This nowCOAST time-enabled map service provides map depicting the latest surface weather and marine weather observations at observing sites using the international station model. The station model is method for representing information collected at an observing station using symbols and numbers. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, visibility, air temperature, dew point temperature, sea surface water temperature, significant wave height, air pressure adjusted to mean sea level, and the change in air pressure over the last 3 hours. The circle in the model is centered over the latitude and longitude coordinates of the station. The total cloud cover is expressed as a fraction of cloud covering the sky and is indicated by the amount of circle filled in. (Cloud cover is not presently displayed due to a problem with the source data. Present weather information is also not available for display at this time.) Wind speed and direction are represented by a wind barb whose line extends from the cover cloud circle towards the direction from which the wind is blowing. The short lines or flags coming off the end of the long line are called barbs. The barb indicates the wind speed in knots. Each normal barb represents 10 knots, while short barbs indicate 5 knots. A flag represents 50 knots. If there is no wind barb depicted, an outer circle around the cloud cover symbol indicates calm winds. The map of observations are updated in the nowCOAST map service approximately every 10 minutes. However, since the reporting frequency varies by network or station, the observation at a particular station may have not updated and may not update until after the next hour. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The maps of near-real-time surface weather and ocean observations are based on non-restricted data obtained from the NWS Family of Services courtesy of NESDIS/OPSD and also the NWS Meteorological Assimilation Data Ingest System (MADIS). The data includes observations from terrestrial and maritime observing from the U.S.A. and other countries. For terrestrial networks, the platforms including but not limited to ASOS, AWOS, RAWS, non-automated stations, U.S. Climate Reference Networks, many U.S. Geological Survey Stations via NWS HADS, several state DOT Road Weather Information Systems, and U.S. Historical Climatology Network-Modernization. For over maritime areas, the platforms include NOS/CO-OPS National Water Level Observation Network (NWLON), NOS/CO-OPS Physical Oceanographic Observing Network (PORTS), NWS/NDBC Fixed Buoys, NDBC Coastal-Marine Automated Network (C-MAN), drifting buoys, ferries, Regional Ocean Observing System (ROOS) coastal stations and buoys, and ships participating in the Voluntary Ship Observing (VOS) Program. Observations from MADIS are updated approximately every 10 minutes in the map service and those from NESDIS are updated every hour. However, not all stations report that frequently. Many stations only report once per hour sometime between 15 minutes before the hour and 30 minutes past the hour. For these stations, new observations will not appear until 22 minutes past top of the hour for land-based stations and 32 minutes past the top of the hour for maritime stations.

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at: http://new.nowcoast.noaa.gov/help/#section=layerinfo

• NWS, 2013: Sample Station Plot, NWS/NCEP/WPC, College Park, MD (Available at http://www.hpc.ncep.noaa.gov/html/stationplot.shtml).
• NWS, 2013: Terminology and Weather Symbols, NWS/NCEP/OPC, College Park, MD (Available at http://www.opc.ncep.noaa.gov/product_description/keyterm.shtml).
• NWS, 2013: How to read Surface weather maps, JetStream an Online School for Weather (Available at http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm).

This nowCOAST time-enabled map service provides map depicting the latest surface weather and marine weather observations at observing sites using the international station model. The station model is method for representing information collected at an observing station using symbols and numbers. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, visibility, air temperature, dew point temperature, sea surface water temperature, significant wave height, air pressure adjusted to mean sea level, and the change in air pressure over the last 3 hours. The circle in the model is centered over the latitude and longitude coordinates of the station. The total cloud cover is expressed as a fraction of cloud covering the sky and is indicated by the amount of circle filled in. (Cloud cover is not presently displayed due to a problem with the source data. Present weather information is also not available for display at this time.) Wind speed and direction are represented by a wind barb whose line extends from the cover cloud circle towards the direction from which the wind is blowing. The short lines or flags coming off the end of the long line are called barbs. The barb indicates the wind speed in knots. Each normal barb represents 10 knots, while short barbs indicate 5 knots. A flag represents 50 knots. If there is no wind barb depicted, an outer circle around the cloud cover symbol indicates calm winds. The map of observations are updated in the nowCOAST map service approximately every 10 minutes. However, since the reporting frequency varies by network or station, the observation at a particular station may have not updated and may not update until after the next hour. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The maps of near-real-time surface weather and ocean observations are based on non-restricted data obtained from the NWS Family of Services courtesy of NESDIS/OPSD and also the NWS Meteorological Assimilation Data Ingest System (MADIS). The data includes observations from terrestrial and maritime observing from the U.S.A. and other countries. For terrestrial networks, the platforms including but not limited to ASOS, AWOS, RAWS, non-automated stations, U.S. Climate Reference Networks, many U.S. Geological Survey Stations via NWS HADS, several state DOT Road Weather Information Systems, and U.S. Historical Climatology Network-Modernization. For over maritime areas, the platforms include NOS/CO-OPS National Water Level Observation Network (NWLON), NOS/CO-OPS Physical Oceanographic Observing Network (PORTS), NWS/NDBC Fixed Buoys, NDBC Coastal-Marine Automated Network (C-MAN), drifting buoys, ferries, Regional Ocean Observing System (ROOS) coastal stations and buoys, and ships participating in the Voluntary Ship Observing (VOS) Program. Observations from MADIS are updated approximately every 10 minutes in the map service and those from NESDIS are updated every hour. However, not all stations report that frequently. Many stations only report once per hour sometime between 15 minutes before the hour and 30 minutes past the hour. For these stations, new observations will not appear until 22 minutes past top of the hour for land-based stations and 32 minutes past the top of the hour for maritime stations.

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at: http://new.nowcoast.noaa.gov/help/#section=layerinfo

• NWS, 2013: Sample Station Plot, NWS/NCEP/WPC, College Park, MD (Available at http://www.hpc.ncep.noaa.gov/html/stationplot.shtml).
• NWS, 2013: Terminology and Weather Symbols, NWS/NCEP/OPC, College Park, MD (Available at http://www.opc.ncep.noaa.gov/product_description/keyterm.shtml).
• NWS, 2013: How to read Surface weather maps, JetStream an Online School for Weather (Available at http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm).

This nowCOAST time-enabled map service provides map depicting the latest surface weather and marine weather observations at observing sites using the international station model. The station model is method for representing information collected at an observing station using symbols and numbers. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, visibility, air temperature, dew point temperature, sea surface water temperature, significant wave height, air pressure adjusted to mean sea level, and the change in air pressure over the last 3 hours. The circle in the model is centered over the latitude and longitude coordinates of the station. The total cloud cover is expressed as a fraction of cloud covering the sky and is indicated by the amount of circle filled in. (Cloud cover is not presently displayed due to a problem with the source data. Present weather information is also not available for display at this time.) Wind speed and direction are represented by a wind barb whose line extends from the cover cloud circle towards the direction from which the wind is blowing. The short lines or flags coming off the end of the long line are called barbs. The barb indicates the wind speed in knots. Each normal barb represents 10 knots, while short barbs indicate 5 knots. A flag represents 50 knots. If there is no wind barb depicted, an outer circle around the cloud cover symbol indicates calm winds. The map of observations are updated in the nowCOAST map service approximately every 10 minutes. However, since the reporting frequency varies by network or station, the observation at a particular station may have not updated and may not update until after the next hour. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The maps of near-real-time surface weather and ocean observations are based on non-restricted data obtained from the NWS Family of Services courtesy of NESDIS/OPSD and also the NWS Meteorological Assimilation Data Ingest System (MADIS). The data includes observations from terrestrial and maritime observing from the U.S.A. and other countries. For terrestrial networks, the platforms including but not limited to ASOS, AWOS, RAWS, non-automated stations, U.S. Climate Reference Networks, many U.S. Geological Survey Stations via NWS HADS, several state DOT Road Weather Information Systems, and U.S. Historical Climatology Network-Modernization. For over maritime areas, the platforms include NOS/CO-OPS National Water Level Observation Network (NWLON), NOS/CO-OPS Physical Oceanographic Observing Network (PORTS), NWS/NDBC Fixed Buoys, NDBC Coastal-Marine Automated Network (C-MAN), drifting buoys, ferries, Regional Ocean Observing System (ROOS) coastal stations and buoys, and ships participating in the Voluntary Ship Observing (VOS) Program. Observations from MADIS are updated approximately every 10 minutes in the map service and those from NESDIS are updated every hour. However, not all stations report that frequently. Many stations only report once per hour sometime between 15 minutes before the hour and 30 minutes past the hour. For these stations, new observations will not appear until 22 minutes past top of the hour for land-based stations and 32 minutes past the top of the hour for maritime stations.

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at: http://new.nowcoast.noaa.gov/help/#section=layerinfo

• NWS, 2013: Sample Station Plot, NWS/NCEP/WPC, College Park, MD (Available at http://www.hpc.ncep.noaa.gov/html/stationplot.shtml).
• NWS, 2013: Terminology and Weather Symbols, NWS/NCEP/OPC, College Park, MD (Available at http://www.opc.ncep.noaa.gov/product_description/keyterm.shtml).
• NWS, 2013: How to read Surface weather maps, JetStream an Online School for Weather (Available at http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm).

This nowCOAST time-enabled map service provides map depicting the latest surface weather and marine weather observations at observing sites using the international station model. The station model is method for representing information collected at an observing station using symbols and numbers. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, visibility, air temperature, dew point temperature, sea surface water temperature, significant wave height, air pressure adjusted to mean sea level, and the change in air pressure over the last 3 hours. The circle in the model is centered over the latitude and longitude coordinates of the station. The total cloud cover is expressed as a fraction of cloud covering the sky and is indicated by the amount of circle filled in. (Cloud cover is not presently displayed due to a problem with the source data. Present weather information is also not available for display at this time.) Wind speed and direction are represented by a wind barb whose line extends from the cover cloud circle towards the direction from which the wind is blowing. The short lines or flags coming off the end of the long line are called barbs. The barb indicates the wind speed in knots. Each normal barb represents 10 knots, while short barbs indicate 5 knots. A flag represents 50 knots. If there is no wind barb depicted, an outer circle around the cloud cover symbol indicates calm winds. The map of observations are updated in the nowCOAST map service approximately every 10 minutes. However, since the reporting frequency varies by network or station, the observation at a particular station may have not updated and may not update until after the next hour. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The maps of near-real-time surface weather and ocean observations are based on non-restricted data obtained from the NWS Family of Services courtesy of NESDIS/OPSD and also the NWS Meteorological Assimilation Data Ingest System (MADIS). The data includes observations from terrestrial and maritime observing from the U.S.A. and other countries. For terrestrial networks, the platforms including but not limited to ASOS, AWOS, RAWS, non-automated stations, U.S. Climate Reference Networks, many U.S. Geological Survey Stations via NWS HADS, several state DOT Road Weather Information Systems, and U.S. Historical Climatology Network-Modernization. For over maritime areas, the platforms include NOS/CO-OPS National Water Level Observation Network (NWLON), NOS/CO-OPS Physical Oceanographic Observing Network (PORTS), NWS/NDBC Fixed Buoys, NDBC Coastal-Marine Automated Network (C-MAN), drifting buoys, ferries, Regional Ocean Observing System (ROOS) coastal stations and buoys, and ships participating in the Voluntary Ship Observing (VOS) Program. Observations from MADIS are updated approximately every 10 minutes in the map service and those from NESDIS are updated every hour. However, not all stations report that frequently. Many stations only report once per hour sometime between 15 minutes before the hour and 30 minutes past the hour. For these stations, new observations will not appear until 22 minutes past top of the hour for land-based stations and 32 minutes past the top of the hour for maritime stations.

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at: http://new.nowcoast.noaa.gov/help/#section=layerinfo

• NWS, 2013: Sample Station Plot, NWS/NCEP/WPC, College Park, MD (Available at http://www.hpc.ncep.noaa.gov/html/stationplot.shtml).
• NWS, 2013: Terminology and Weather Symbols, NWS/NCEP/OPC, College Park, MD (Available at http://www.opc.ncep.noaa.gov/product_description/keyterm.shtml).
• NWS, 2013: How to read Surface weather maps, JetStream an Online School for Weather (Available at http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm).

This nowCOAST time-enabled map service provides maps depicting the latest global forecast guidance of water currents, water temperature, and salinity at forecast projections: 0, 12, 24, 36, 48, 60, 72, 84, and 96-hours from the NWS/NCEP Global Real-Time Ocean Forecast System (GRTOFS). The surface water currents velocity maps displays the direction using white or black streaklets. The magnitude of the current is indicated by the length and width of the streaklet. The maps of the GRTOFS surface forecast guidance are updated on the nowCOAST map service once per day. For more detailed information about the update schedule, see: https://new.nowcoast.noaa.gov/help/#section=updateschedule

GRTOFS is based on the Hybrid Coordinates Ocean Model (HYCOM), an eddy resolving, hybrid coordinate numerical ocean prediction model. GRTOFS has global coverge and a horizontal resolution of 1/12 degree and 32 hybrid vertical layers. It has one forecast cycle per day (i.e. 0000 UTC) which generates forecast guidance out to 144 hours (6 days). However, nowCOAST only provides guidance out to 96 hours (4 days). The forecast cycle uses 3-hourly momentum and radiation fluxes along with precipitation predictions from the NCEP Global Forecast System (GFS). Each forecast cycle is preceded with a 48-hr long nowcast cycle. The nowcast cycle uses daily initial 3-D fields from the NAVOCEANO operational HYCOM-based forecast system which assimilates situ profiles of temperature and salinity from a variety of sources and remotely sensed SST, SSH and sea-ice concentrations. GRTOFS was developed by NCEP/EMC/Marine Modeling and Analysis Programs. GRTOFS is run once per day (0000 UTC forecast cycle) on the NOAA Weather and Climate Operational Supercomputer System (WCOSS) operated by NWS/NCEP Central Operations.

The maps are generated using a visualization technique was developed by the Data Visualization Research Lab at The University of New Hampshire Center for Coastal and Ocean Mapping (https://www.ccom.unh.edu/vislab/). The method combines two techniques. First, equally spaced streamlines are computed in the flow field using Jobard and Lefer's (1977) algorithm. Second, a series of "streaklets" are rendered head to tail along each streamline to show the direction of flow. Each of these varies along its length in size, color and transparency using a method developed by Fowler and Ware (1989), and later refined by Mr. Pete Mitchell and Dr. Colin Ware (Mitchell, 2007).

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at:https://new.nowcoast.noaa.gov/help/#section=layerinfo

• Fowler, D. and C. Ware, 1989: Strokes for Representing Vector Field Maps. Proceedings: Graphics Interface '98 249-253.
• Jobard, B and W. Lefer,1977: Creating evenly spaced streamlines of arbitrary density. Proceedings: Eurographics workshop on Visualization in Scientific Computing. 43-55.
• Mitchell, P.W., 2007: The Perceptual optimization of 2D Flow Visualizations Using Human in the Loop Local Hill Climbing. University of New Hampshire Masters Thesis. Department of Computer Science.
• NWS, 2013: About Global RTOFS, NCEP/EMC/MMAB, College Park, MD (Available at https://polar.ncep.noaa.gov/global/about/).
• Chassignet, E.P., H.E. Hurlburt, E.J. Metzger, O.M. Smedstad, J. Cummings, G.R. Halliwell, R. Bleck, R. Baraille, A.J. Wallcraft, C. Lozano, H.L. Tolman, A. Srinivasan, S. Hankin, P. Cornillon, R. Weisberg, A. Barth, R. He, F. Werner, and J. Wilkin, 2009: U.S. GODAE: Global Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanography, 22(2), 64-75.
• Mehra, A, I. Rivin, H. Tolman, T. Spindler, and B. Balasubramaniyan, 2011: A Real-Time Operational Global Ocean Forecast System, Poster, GODAE OceanView –GSOP-CLIVAR Workshop in Observing System Evaluation and Intercomparisons, Santa Cruz, CA.

This nowCOAST time-enabled map service provides maps depicting NWS gridded forecasts of the following selected sensible surface weather variables or elements: air temperature (including daily maximum and minimum), apparent air temperature, dew point temperature, relative humidity, wind velocity, wind speed, wind gust, total sky cover, and significant wave height for the next 6-7 days. Additional forecast maps are available for 6-hr quantitative precipitation (QPF), 6-hr quantitative snowfall, and 12-hr probability of precipitation. These NWS forecasts are from the National Digital Forecast Database (NDFD) at a 2.5 km horizontal spatial resolution. Surface is defined as 10 m (33 feet) above ground level (AGL) for wind variables and 2 m (5.5 ft) AGL for air temperature, dew point temperature, and relative humidity variables. The forecasts extend out to 7 days from 0000 UTC on Day 1 (current day). The forecasts are updated in the nowCOAST map service four times per day. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The forecast projection availability times listed below are generally accurate, however forecast interval and forecast horizon vary by region and variable. For the most up-to-date information, please see http://www.nws.noaa.gov/ndfd/resources/NDFD_element_status.pdf and http://graphical.weather.gov/docs/datamanagement.php.

The forecasts of the air, apparent, and dew point temperatures are displayed using different colors at 2 degree Fahrenheit increments from -30 to 130 degrees F in order to use the same color legend throughout the year for the United States. This is the same color scale used for displaying the NDFD maximum and minimum air temperature forecasts. Air and dew point temperature forecasts are available every hour out to +36 hours from forecast issuance time, at 3-hour intervals from +36 to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days). Maximum and minimum air temperature forecasts are each available every 24 hours out to +168 hours (7 days) from 0000 UTC on Day 1 (current day).

The relative humidity (RH) forecasts are depicted using different colors for every 5-percent interval. The increment and color scale used to display the RH forecasts were developed to highlight NWS local fire weather watch/red flag warning RH criteria at the low end (e.g. 15, 25, & 35% thresholds) and important high end RH thresholds for other users (e.g. agricultural producers) such as 95%. The RH forecasts are available every hour out to +36 hours from 0000 UTC on Day 1 (current day), at 3-hour intervals from +36 to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days).

The 6-hr total precipitation amount forecasts or QPFs are symbolized using different colors at 0.01, 0.10, 0.25 inch intervals, at 1/4 inch intervals up to 4.0 (e.g. 0.50, 0.75, 1.00, 1.25, etc.), at 1-inch intervals from 4 to 10 inches and then at 2-inch intervals up to 14 inches. The increments from 0.01 to 1.00 or 2.00 inches are similar to what are used on NCEP/Weather Prediction Center's QPF products and the NWS River Forecast Center (RFC) daily precipitation analysis. Precipitation forecasts are available for each 6-hour period out to +72 hours (3 days) from 0000 UTC on Day 1 (current day).

The 6-hr total snowfall amount forecasts are depicted using different colors at 1-inch intervals for snowfall greater than 0.01 inches. Snowfall forecasts are available for each 6-hour period out to +48 hours (2 days) from 0000 UTC on Day 1 (current day).

The 12-hr probability of precipitation (PoP) forecasts are displayed for probabilities over 10 percent using different colors at 10, 20, 30, 60, and 85+ percent. The probability of precipitation forecasts are available for each 12-hour period out to +72 hours (3 days) from 0000 UTC on Day 1 (current day).

The wind speed and wind gust forecasts are depicted using different colors at 5 knots increment up to 115 knots. The legend includes tick marks for both knots and miles per hour. The same color scale is used for displaying the RTMA surface wind speed forecasts. The wind velocity is depicted by curved wind barbs along streamlines. The direction of the wind is indicated with an arrowhead on the wind barb. The flags on the wind barb are the standard meteorological convention in units of knots. The wind speed and wind velocity forecasts are available hourly out to +36 hours from 00:00 UTC on Day 1 (current day), at 3-hour intervals out to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days). The wind gust forecasts are available hourly out to +36 hours from 0000 UTC on Day 1 (current day) and at 3-hour intervals out to +72 hours (3 days).

The total sky cover forecasts are displayed using progressively darker shades of gray for 10, 30, 60, and 80+ percentage values. Sky cover values under 10 percent are shown as transparent. The sky cover forecasts are available for each hour out to +36 hours from 0000 UTC on Day 1 (current day), every 3 hours from +36 to +72 hours, and every 6 hours from +72 to +168 hours (7 days).

The significant wave height forecasts are symbolized with different colors at 1-foot intervals up to 20 feet and at 5-foot intervals from 20 feet to 35+ feet. The significant wave height forecasts are available for each hour out to +36 hours from 0000 UTC on Day 1 (current day), every 3 hours from +36 to +72 hours, and every 6 hours from +72 to +144 hours (6 days).

Background Information

The NDFD is a seamless composite or mosaic of gridded forecasts from individual NWS Weather Forecast Offices (WFOs) from around the U.S. as well as the NCEP/Ocean Prediction Center and National Hurricane Center/TAFB. NDFD has a spatial resolution of 2.5 km. The 2.5km resolution NDFD forecasts are presently experimental, but are scheduled to become operational in May/June 2014. The time resolution of forecast projections varies by variable (element) based on user needs, forecast skill, and forecaster workload. Each WFO prepares gridded NDFD forecasts for their specific geographic area of responsibility. When these locally generated forecasts are merged into a national mosaic, occasionally areas of discontinuity will be evident. Staff at NWS forecast offices attempt to resolve discontinuities along the boundaries of the forecasts by coordinating with forecasters at surrounding WFOs and using workstation forecast tools that identify and resolve some of these differences. The NWS is making progress in this area, and recognizes that this is a significant issue in which improvements are still needed. The NDFD was developed by NWS Meteorological Development Laboratory.

As mentioned above, a curved wind barb with an arrow head is used to display the wind velocity forecasts instead of the traditional wind barb. The curved wind barb was developed and evaluated at the Data Visualization Laboratory of the NOAA-UNH Joint Hydrographic Center/Center for Coastal and Ocean Mapping (Ware et al., 2014). The curved wind barb combines the best features of the wind barb, that it displays speed in a readable form, with the best features of the streamlines which shows wind patterns. The arrow head helps to convey the flow direction.

Time Information

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes

This nowCOAST time-enabled map service provides maps depicting the latest global forecast guidance of water currents, water temperature, and salinity at forecast projections: 0, 12, 24, 36, 48, 60, 72, 84, and 96-hours from the NWS/NCEP Global Real-Time Ocean Forecast System (GRTOFS). The surface water currents velocity maps displays the direction using white or black streaklets. The magnitude of the current is indicated by the length and width of the streaklet. The maps of the GRTOFS surface forecast guidance are updated on the nowCOAST map service once per day. For more detailed information about the update schedule, see: https://new.nowcoast.noaa.gov/help/#section=updateschedule

GRTOFS is based on the Hybrid Coordinates Ocean Model (HYCOM), an eddy resolving, hybrid coordinate numerical ocean prediction model. GRTOFS has global coverge and a horizontal resolution of 1/12 degree and 32 hybrid vertical layers. It has one forecast cycle per day (i.e. 0000 UTC) which generates forecast guidance out to 144 hours (6 days). However, nowCOAST only provides guidance out to 96 hours (4 days). The forecast cycle uses 3-hourly momentum and radiation fluxes along with precipitation predictions from the NCEP Global Forecast System (GFS). Each forecast cycle is preceded with a 48-hr long nowcast cycle. The nowcast cycle uses daily initial 3-D fields from the NAVOCEANO operational HYCOM-based forecast system which assimilates situ profiles of temperature and salinity from a variety of sources and remotely sensed SST, SSH and sea-ice concentrations. GRTOFS was developed by NCEP/EMC/Marine Modeling and Analysis Programs. GRTOFS is run once per day (0000 UTC forecast cycle) on the NOAA Weather and Climate Operational Supercomputer System (WCOSS) operated by NWS/NCEP Central Operations.

The maps are generated using a visualization technique was developed by the Data Visualization Research Lab at The University of New Hampshire Center for Coastal and Ocean Mapping (https://www.ccom.unh.edu/vislab/). The method combines two techniques. First, equally spaced streamlines are computed in the flow field using Jobard and Lefer's (1977) algorithm. Second, a series of "streaklets" are rendered head to tail along each streamline to show the direction of flow. Each of these varies along its length in size, color and transparency using a method developed by Fowler and Ware (1989), and later refined by Mr. Pete Mitchell and Dr. Colin Ware (Mitchell, 2007).

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at:https://new.nowcoast.noaa.gov/help/#section=layerinfo

• Fowler, D. and C. Ware, 1989: Strokes for Representing Vector Field Maps. Proceedings: Graphics Interface '98 249-253.
• Jobard, B and W. Lefer,1977: Creating evenly spaced streamlines of arbitrary density. Proceedings: Eurographics workshop on Visualization in Scientific Computing. 43-55.
• Mitchell, P.W., 2007: The Perceptual optimization of 2D Flow Visualizations Using Human in the Loop Local Hill Climbing. University of New Hampshire Masters Thesis. Department of Computer Science.
• NWS, 2013: About Global RTOFS, NCEP/EMC/MMAB, College Park, MD (Available at https://polar.ncep.noaa.gov/global/about/).
• Chassignet, E.P., H.E. Hurlburt, E.J. Metzger, O.M. Smedstad, J. Cummings, G.R. Halliwell, R. Bleck, R. Baraille, A.J. Wallcraft, C. Lozano, H.L. Tolman, A. Srinivasan, S. Hankin, P. Cornillon, R. Weisberg, A. Barth, R. He, F. Werner, and J. Wilkin, 2009: U.S. GODAE: Global Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanography, 22(2), 64-75.
• Mehra, A, I. Rivin, H. Tolman, T. Spindler, and B. Balasubramaniyan, 2011: A Real-Time Operational Global Ocean Forecast System, Poster, GODAE OceanView –GSOP-CLIVAR Workshop in Observing System Evaluation and Intercomparisons, Santa Cruz, CA.

This nowCOAST time-enabled map service provides maps depicting NWS gridded forecasts of the following selected sensible surface weather variables or elements: air temperature (including daily maximum and minimum), apparent air temperature, dew point temperature, relative humidity, wind velocity, wind speed, wind gust, total sky cover, and significant wave height for the next 6-7 days. Additional forecast maps are available for 6-hr quantitative precipitation (QPF), 6-hr quantitative snowfall, and 12-hr probability of precipitation. These NWS forecasts are from the National Digital Forecast Database (NDFD) at a 2.5 km horizontal spatial resolution. Surface is defined as 10 m (33 feet) above ground level (AGL) for wind variables and 2 m (5.5 ft) AGL for air temperature, dew point temperature, and relative humidity variables. The forecasts extend out to 7 days from 0000 UTC on Day 1 (current day). The forecasts are updated in the nowCOAST map service four times per day. For more detailed information about the update schedule, please see: https://new.nowcoast.noaa.gov/help/#section=updateschedule

The forecast projection availability times listed below are generally accurate, however forecast interval and forecast horizon vary by region and variable. For the most up-to-date information, please see https://graphical.weather.gov/docs/datamanagement.php.

The forecasts of the air, apparent, and dew point temperatures are displayed using different colors at 2 degree Fahrenheit increments from -30 to 130 degrees F in order to use the same color legend throughout the year for the United States. This is the same color scale used for displaying the NDFD maximum and minimum air temperature forecasts. Air and dew point temperature forecasts are available every hour out to +36 hours from forecast issuance time, at 3-hour intervals from +36 to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days). Maximum and minimum air temperature forecasts are each available every 24 hours out to +168 hours (7 days) from 0000 UTC on Day 1 (current day).

The relative humidity (RH) forecasts are depicted using different colors for every 5-percent interval. The increment and color scale used to display the RH forecasts were developed to highlight NWS local fire weather watch/red flag warning RH criteria at the low end (e.g. 15, 25, & 35% thresholds) and important high end RH thresholds for other users (e.g. agricultural producers) such as 95%. The RH forecasts are available every hour out to +36 hours from 0000 UTC on Day 1 (current day), at 3-hour intervals from +36 to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days).

The 6-hr total precipitation amount forecasts or QPFs are symbolized using different colors at 0.01, 0.10, 0.25 inch intervals, at 1/4 inch intervals up to 4.0 (e.g. 0.50, 0.75, 1.00, 1.25, etc.), at 1-inch intervals from 4 to 10 inches and then at 2-inch intervals up to 14 inches. The increments from 0.01 to 1.00 or 2.00 inches are similar to what are used on NCEP/Weather Prediction Center's QPF products and the NWS River Forecast Center (RFC) daily precipitation analysis. Precipitation forecasts are available for each 6-hour period out to +72 hours (3 days) from 0000 UTC on Day 1 (current day).

The 6-hr total snowfall amount forecasts are depicted using different colors at 1-inch intervals for snowfall greater than 0.01 inches. Snowfall forecasts are available for each 6-hour period out to +48 hours (2 days) from 0000 UTC on Day 1 (current day).

The 12-hr probability of precipitation (PoP) forecasts are displayed for probabilities over 10 percent using different colors at 10, 20, 30, 60, and 85+ percent. The probability of precipitation forecasts are available for each 12-hour period out to +72 hours (3 days) from 0000 UTC on Day 1 (current day).

The wind speed and wind gust forecasts are depicted using different colors at 5 knots increment up to 115 knots. The legend includes tick marks for both knots and miles per hour. The same color scale is used for displaying the RTMA surface wind speed forecasts. The wind velocity is depicted by curved wind barbs along streamlines. The direction of the wind is indicated with an arrowhead on the wind barb. The flags on the wind barb are the standard meteorological convention in units of knots. The wind speed and wind velocity forecasts are available hourly out to +36 hours from 00:00 UTC on Day 1 (current day), at 3-hour intervals out to +72 hours, and at 6-hour intervals from +72 to +168 hours (7 days). The wind gust forecasts are available hourly out to +36 hours from 0000 UTC on Day 1 (current day) and at 3-hour intervals out to +72 hours (3 days).

The total sky cover forecasts are displayed using progressively darker shades of gray for 10, 30, 60, and 80+ percentage values. Sky cover values under 10 percent are shown as transparent. The sky cover forecasts are available for each hour out to +36 hours from 0000 UTC on Day 1 (current day), every 3 hours from +36 to +72 hours, and every 6 hours from +72 to +168 hours (7 days).

The significant wave height forecasts are symbolized with different colors at 1-foot intervals up to 20 feet and at 5-foot intervals from 20 feet to 35+ feet. The significant wave height forecasts are available for each hour out to +36 hours from 0000 UTC on Day 1 (current day), every 3 hours from +36 to +72 hours, and every 6 hours from +72 to +144 hours (6 days).

Background Information

The NDFD is a seamless composite or mosaic of gridded forecasts from individual NWS Weather Forecast Offices (WFOs) from around the U.S. as well as the NCEP/Ocean Prediction Center and National Hurricane Center/TAFB. NDFD has a spatial resolution of 2.5 km. The 2.5km resolution NDFD forecasts are presently experimental, but are scheduled to become operational in May/June 2014. The time resolution of forecast projections varies by variable (element) based on user needs, forecast skill, and forecaster workload. Each WFO prepares gridded NDFD forecasts for their specific geographic area of responsibility. When these locally generated forecasts are merged into a national mosaic, occasionally areas of discontinuity will be evident. Staff at NWS forecast offices attempt to resolve discontinuities along the boundaries of the forecasts by coordinating with forecasters at surrounding WFOs and using workstation forecast tools that identify and resolve some of these differences. The NWS is making progress in this area, and recognizes that this is a significant issue in which improvements are still needed. The NDFD was developed by NWS Meteorological Development Laboratory.

As mentioned above, a curved wind barb with an arrow head is used to display the wind velocity forecasts instead of the traditional wind barb. The curved wind barb was developed and evaluated at the Data Visualization Laboratory of the NOAA-UNH Joint Hydrographic Center/Center for Coastal and Ocean Mapping (Ware et al., 2014). The curved wind barb combines the best features of the wind barb, that it displays speed in a readable form, with the best features of the streamlines which shows wind patterns. The arrow head helps to convey the flow direction.

Time Information

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end

This nowCOAST time-enabled map service provides map depicting the latest surface weather and marine weather observations at observing sites using the international station model. The station model is method for representing information collected at an observing station using symbols and numbers. The station model depicts current weather conditions, cloud cover, wind speed, wind direction, visibility, air temperature, dew point temperature, sea surface water temperature, significant wave height, air pressure adjusted to mean sea level, and the change in air pressure over the last 3 hours. The circle in the model is centered over the latitude and longitude coordinates of the station. The total cloud cover is expressed as a fraction of cloud covering the sky and is indicated by the amount of circle filled in. (Cloud cover is not presently displayed due to a problem with the source data. Present weather information is also not available for display at this time.) Wind speed and direction are represented by a wind barb whose line extends from the cover cloud circle towards the direction from which the wind is blowing. The short lines or flags coming off the end of the long line are called barbs. The barb indicates the wind speed in knots. Each normal barb represents 10 knots, while short barbs indicate 5 knots. A flag represents 50 knots. If there is no wind barb depicted, an outer circle around the cloud cover symbol indicates calm winds. The map of observations are updated in the nowCOAST map service approximately every 10 minutes. However, since the reporting frequency varies by network or station, the observation at a particular station may have not updated and may not update until after the next hour. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule

The maps of near-real-time surface weather and ocean observations are based on non-restricted data obtained from the NWS Family of Services courtesy of NESDIS/OPSD and also the NWS Meteorological Assimilation Data Ingest System (MADIS). The data includes observations from terrestrial and maritime observing from the U.S.A. and other countries. For terrestrial networks, the platforms including but not limited to ASOS, AWOS, RAWS, non-automated stations, U.S. Climate Reference Networks, many U.S. Geological Survey Stations via NWS HADS, several state DOT Road Weather Information Systems, and U.S. Historical Climatology Network-Modernization. For over maritime areas, the platforms include NOS/CO-OPS National Water Level Observation Network (NWLON), NOS/CO-OPS Physical Oceanographic Observing Network (PORTS), NWS/NDBC Fixed Buoys, NDBC Coastal-Marine Automated Network (C-MAN), drifting buoys, ferries, Regional Ocean Observing System (ROOS) coastal stations and buoys, and ships participating in the Voluntary Ship Observing (VOS) Program. Observations from MADIS are updated approximately every 10 minutes in the map service and those from NESDIS are updated every hour. However, not all stations report that frequently. Many stations only report once per hour sometime between 15 minutes before the hour and 30 minutes past the hour. For these stations, new observations will not appear until 22 minutes past top of the hour for land-based stations and 32 minutes past the top of the hour for maritime stations.

This map is time-enabled, meaning that each individual layer contains time-varying data and can be utilized by clients capable of making map requests that include a time component.

This particular service can be queried with or without the use of a time component. If the time parameter is specified in a request, the data or imagery most relevant to the provided time value, if any, will be returned. If the time parameter is not specified in a request, the latest data or imagery valid for the present system time will be returned to the client. If the time parameter is not specified and no data or imagery is available for the present time, no data will be returned.

In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service.

Due to software limitations, the time extent of the service and map layers displayed below does not provide the most up-to-date start and end times of available data. Instead, users have three options for determining the latest time information about the service:

1. Issue a returnUpdates=true request for an individual layer or for the service itself, which will return the current start and end times of available data, in epoch time format (milliseconds since 00:00 January 1, 1970). To see an example, click on the "Return Updates" link at the bottom of this page under "Supported Operations". Refer to the ArcGIS REST API Map Service Documentation for more information.
2. Issue an Identify (ArcGIS REST) or GetFeatureInfo (WMS) request against the proper layer corresponding with the target dataset. For raster data, this would be the "Image Footprints with Time Attributes" layer in the same group as the target "Image" layer being displayed. For vector (point, line, or polygon) data, the target layer can be queried directly. In either case, the attributes returned for the matching raster(s) or vector feature(s) will include the following:
   • validtime: Valid timestamp.
   • starttime: Display start time.
   • endtime: Display end time.
   • reftime: Reference time (sometimes reffered to as issuance time, cycle time, or initialization time).
   • projmins: Number of minutes from reference time to valid time.
   • desigreftime: Designated reference time; used as a common reference time for all items when individual reference times do not match.
   • desigprojmins: Number of minutes from designated reference time to valid time.
3. Query the nowCOAST LayerInfo web service, which has been created to provide additional information about each data layer in a service, including a list of all available "time stops" (i.e. "valid times"), individual timestamps, or the valid time of a layer's latest available data (i.e. "Product Time"). For more information about the LayerInfo web service, including examples of various types of requests, refer to the nowCOAST help documentation at: http://new.nowcoast.noaa.gov/help/#section=layerinfo

• NWS, 2013: Sample Station Plot, NWS/NCEP/WPC, College Park, MD (Available at http://www.hpc.ncep.noaa.gov/html/stationplot.shtml).
• NWS, 2013: Terminology and Weather Symbols, NWS/NCEP/OPC, College Park, MD (Available at http://www.opc.ncep.noaa.gov/product_description/keyterm.shtml).
• NWS, 2013: How to read Surface weather maps, JetStream an Online School for Weather (Available at http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm).