Service Records and Retention System (SRRS) is historical digital data set DSI-9949, a collection of products created by the U.S. National Weather Service (NWS) and archived at the National Centers for Environmental Information (NCEI) [formerly National Climatic Data Center (NCDC)]. SRRS was a network of computers and associated hardware whose purpose was to transmit and store a large number of NWS products and make them available as needed. Basic meteorological and hydrological data, analyses, forecasts, and warnings are distributed among NWS offices over the AFOS (Automation of Field Operations and Services) communications system since 1978. These include PIREP (aircraft reports from pilots), AIRMET (aeronautical meteorological bulletins), SIGMET (significant meteorological information), surface and upper air plotted unanalyzed maps, air stagnation, precipitable water, Forecasts such as wind and temperature aloft, thickness and analysis, fire weather, area, local, zone, state, agricultural advisory, and terminal; and Warnings such as marine, severe weather, hurricane and tornado. The AFOS system was developed to increase the productivity and effectiveness of NWS personnel and to increase the timeliness and quality of their warning and forecasting services. This format version of the SRRS data was archived at NCEI from 1983 to 2001 (when a new format was created). The NCEI can service requests for products from the SRRS; two types of products are available to the user: 1) graphic displays of meteorological analyses and forecast charts (limited), and 2) alphanumeric displays of narrative summaries and meteorological/hydrological data. The following is a partial list of historical SRRS products available through the NCDC: rawinsonde data above 100 MB; AIREPS buoy reports; coastal flood warning; Coast Guard surface report; climatological report (daily and misc, incl monthly reports); weather advisory Coastal Waters Forecast Center (CWSU); weather statement; 3- to 5-day extended forecast; average 6- to 10-day weather outlook (local and national); aviation area forecast winds aloft forecast; flash flood statements, watches and warnings; flood statement; flood warning forecast; medium range guidance; FOUS relative humidity/temperature guidance; FOUS prog max/min temp/POP guidance; FOUS wind/cloud guidance; Great Lakes forecast; hurricane local statement; high seas forecast; international aviation observations; local forecast; local storm report; rawinsonde observation - mandatory levels;, METAR formatted surface weather observation; marine weather statement; short term rorecast; non-precipitation warnings/watches/advisories; nearshore marine forecast (Great Lakes only), offshore aviation area forecast; offshore forecast; other marine products, other surface weather observations, pilot report plain language, ship report, state pilot report, collective recreational report; narrative radar summary radar observation; hydrology-meteorology data report; river summary; river forecast; miscellaneous river product; river recreation statement; ; regional weather summary; surface aviation observation; preliminary notice of watch and canc msg SVR; local storm watch and warning; cancelation msg SELS watch; point information message; state forecast discussion ; state forecast rawinsonde observation - significant levels; surface ship report at intermediate synoptic time; surface ship report at non-synoptic time; surface ship report at synoptic time; special weather statement international; SIGMET severe local storm watch and area outline; special marine warning; intermediate surface synoptic observation; main surface synoptic observation; severe thunderstorm warning; severe weather statement; severe storm outlook; narrative state weather summary; terminal forecast; tropical cyclone discussion; marine/aviation tropical cyclone advisory; public tropical cyclone advisory; tornado warning; transcribed weather broadcast; tropical weather discussion; tropical weather outlook and summary; AIRMET SIGMET zone forecast; terminal forecast (prior to 7/1/96); winter weather warnings, watches, advisories; marine advisory/warning; special marine warning; miscellaneous product convective SIGMET ; local ice forecast; area forecast discussion; public information statement. SRRS (DSI-9949) by the Gateway SRRS (DSI-9957; C00583). NWS products after 2001 can be obtained from those systems, from NCEI.

This map displays the expected total accumulation of new snow over the next 72 hours across the contiguous United States. Data are updated hourly from the National Digital Forecast Database produced by the National Weather Service.The dataset includes incremental and cumulative snowfall data in 6-hour intervals. In the ArcGIS Online map viewer you can enable the time animation feature and select either the amount by time (incremental) or accumulation by time (cumulative) layers to view a 72-hour animation of forecast precipitation. All times are reported according to your local time zone.Where is the data coming from?The National Digital Forecast Database (NDFD) was designed to provide access to weather forecasts in digital form from a central location. The NDFD produces gridded forecasts of sensible weather elements. NDFD contains a seamless mosaic of digital forecasts from National Weather Service (NWS) field offices working in collaboration with the National Centers for Environmental Prediction (NCEP). All of these organizations are under the administration of the National Oceanic and Atmospheric Administration (NOAA).Source: https://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/DF.gr2/DC.ndfd/AR.conus/VP.001-003/ds.snow.binWhere can I find other NDFD data?The Source data is downloaded and parsed using the Aggregated Live Feeds methodology to return information that can be served through ArcGIS Server as a map service or used to update Hosted Feature Services in Online or Enterprise.What can you do with this layer?This map service is suitable for data discovery and visualization. Identify features by clicking on the map to reveal the pre-configured pop-ups. View the time-enabled data using the time slider by Enabling Time Animation.This map is provided for informational purposes and is not monitored 24/7 for accuracy and currency.If you would like to be alerted to potential issues or simply see when this Service will update next, please visit our Live Feed Status Page!

This dataset contains the Coded Surface Bulletin (CSB) dataset reformatted as netCDF-4 files. The CSB dataset is a collection of ASCII files containing the locations of weather fronts, troughs, high pressure centers, and low pressure centers as determined by National Weather Service meteorologists at the Weather Prediction Center (WPC) during the surface analysis they do every three hours. Each bulletin is broadcast on the NOAAPort service, and has been available since 2003.

Each netCDF file contains one year of CSB fronts data represented as spatial map data grids. The times and geospatial locations for the data grid cells are also included. The front data is stored in a netCDF variable with dimensions (time, front type, y, x), where x and y are geospatial dimensions. There is a 2D geospatial data grid for each time step for each of the 4 front types—cold, warm, stationary, and occluded. The front polylines from the CSB dataset are rasterized into the appropriate data grids. Each file conforms to the Climate and Forecast Metadata Conventions.

There are two large groupings of the CSB netCDF files. One group uses a data grid based on the North American Regional Reanalysis (NARR) grid, which is a Lambert Conformal Conic projection coordinate reference system (CRS) centered over North America. The NARR grid is quite close the the spatial range of data displayed on the WPC workstations used to perform surface analysis and identify front locations. The native NARR grid has grid cells which are 32 km on each side. Our grid covers the same extents with cells that are 96 km on each side.

The other group uses a 1° latitude/longitude data grid centered over North America with extents 171W – 31W / 10N – 77 N. The files in this group are identified by the name MERRA2, because they were used with data from the NASA MERRA-2 dataset, which uses a latitude/longitude data grid.

There are a number of files within each group. The files all follow the naming convention codsus_[masked]_.nc, where [masked] indicates that the presence of the word masked is optional and is either merra2-1deg or narr-96km. The element is either the word mask or the sequence wide_, where is the front width and is the year for the data stored in the file.

The codsus_mask.nc file is a file containing a single data grid that delineates the envelope of the geospatial region where there are, on average, 40 or more front crossing of any type per year. The WPC meteorologists don't attempt to provide equal levels of attention to every grid cell displayed on their workstations. The files of the form codsus_masked_wide_.nc have all had the mask described above applied to exclude parts of fronts that extend past the envelope. The files of the form codsus_wide_.nc have no masking applied.

The wide portion of the file names takes two forms—1wide and 3wide. The fronts in the1wide files were rasterized by drawing the front polylines with a width of one grid cell. The fronts in the 3wide files were rasterized by drawing the front polylines with a width of 3 grid cells.

Within each grid group, there are five subsets of files:

codsus_masked_1wide_.nc

codsus_masked_3wide_.nc

codsus_1wide_.nc

codsus_3wide_.nc

codsus_mask.nc

The primary source for this dataset is an internal archive maintained by personnel at the WPC and provided to the author. It is also provided at DOI 10.5281/zenodo.2642801. Some bulletins missing from the WPC archive were filled in with data acquired from the Iowa Environmental Mesonet.

Hourly Precipitation Data (HPD) is digital data set DSI-3240, archived at the National Climatic Data Center (NCDC). The primary source of data for this file is approximately 5,500 US National Weather Service (NWS), Federal Aviation Administration (FAA), and cooperative observer stations in the United States of America, Puerto Rico, the US Virgin Islands, and various Pacific Islands. The earliest data dates vary considerably by state and region: Maine, Pennsylvania, and Texas have data since 1900. The western Pacific region that includes Guam, American Samoa, Marshall Islands, Micronesia, and Palau have data since 1978. Other states and regions have earliest dates between those extremes. The latest data in all states and regions is from the present day. The major parameter in DSI-3240 is precipitation amounts, which are measurements of hourly or daily precipitation accumulation. Accumulation was for longer periods of time if for any reason the rain gauge was out of service or no observer was present. DSI 3240_01 contains data grouped by state; DSI 3240_02 contains data grouped by year.

About the data:

Stream gauges with flooding: This is an aggregated live feed derived from the NOAA/USGS Stream Gauges site using the National Weather Service’s River Observation data.

Weather Watches and Warnings: This is an aggregated live feed derived from the NOAA Weather Warnings Watches and Advisory data provided through the Common Alerting Protocol (CAP) Alert system.

72-hour Forecast Total Precipitation: The data displaying forecast precipitation for the next 72 hours is Quantitative Precipitation Forecast (QPF). QPF is the amount of expected rainfall (in hundredths of inches) every six hours. This data is recorded by NDFD at 0000, 0600, 1200 and 1800. Organization: NDFD (National Digital Forecast Database)

Radar: Provided by AccuWeather, Inc.. For more information on the predictive services AccuWeather provides visit the ArcGIS Marketplace.

This Global Summaries dataset, known as GSOY for Yearly, contains a yearly resolution of meteorological elements from 1763 to present with updates applied weekly. The major parameters are: – average annual temperature, average annual minimum and maximum temperatures; total annual precipitation and snowfall; departure from normal of the mean temperature and total precipitation; heating and cooling degree days; number of days that temperatures and precipitation are above or below certain thresholds; extreme annual minimum and maximum temperatures; number of days with fog; and number of days with thunderstorms. The primary input data source is the Global Historical Climatology Network - Daily (GHCN-Daily) dataset. The Global Summaries datasets also include a monthly resolution of meteorological elements in the GSOM (for Monthly) dataset. See associated resources for more information. These datasets are not to be confused with "GHCN-Monthly", "Annual Summaries" or "NCDC Summary of the Month". There are unique elements that are produced globally within the GSOM and GSOY data files. There are also bias corrected temperature data in GHCN-Monthly, which are not available in GSOM and GSOY. The GSOM and GSOY datasets replace the legacy U.S. COOP Summaries (DSI-3220), and have been expanded to include non-U.S. (global) stations. U.S. COOP Summaries (DSI-3220) only includes National Weather Service (NWS) COOP Published, or "Published in CD", sites.

Q: Where is severe weather likely at this time of year? A: Shading on each map reflects how often severe weather occurred within 25 miles during a 30-year base period. The darker the shading, the higher the number of severe weather reports near that date. For this map, severe weather encompasses tornadoes, thunderstorm winds over 58 miles per hour, and hail larger than three-quarters of an inch in diameter. Q: How were these maps produced? A: For each day of the year, scientists plotted reports of severe weather from 1982 to 2011 on a gridded map. To reveal the long-term patterns of these events, they applied mathematical filters to smooth the counts in time and space. Keep in mind that severe weather is possible at any location on any day of the year. Q: What do the colors mean? A: Shaded areas show the historical probability of severe weather occurring within 25 miles. Meteorologists estimated these probabilities from severe weather reports submitted from 1982-2011. For each day of the year, scientists plotted reports of severe events onto a map marked with grid cells 50 miles on a side. For each grid cell, they counted the number of years with at least one report, and divided by the total number of years. To reveal the long-term patterns suggested by this relatively small dataset, they used statistical methods to smooth the data. For instance, to smooth clusters of events in time, a mathematical filter replaced the value in every grid cell with a 15-day average. Another filter extended report locations over a 25-mile-wide circle to indicate the probability that the event could have occurred at other points within that area. Q: Why do these data matter? A: Knowing when and where severe weather tends to occur through the year promotes preparedness. Residents who are alert to the possibility of severe weather are better able to respond in ways that keep them safe. These data can also help emergency response personnel plan for when and where their services may be necessary. Q: How did you produce these snapshots? A: Data Snapshots are derivatives of existing data products: to meet the needs of a broad audience, we present the source data in a simplified visual style. NOAA's National Weather Service Storm Prediction Center produced the Severe Weather Climatology files. To produce our images, we obtained the climatology data as a numpy array, and ran a set of scripts to display the mapped areas on our base maps with a custom color bar. Additional information Data for these images represents an update and extension of work first put forth by Dr. Harold Brooks of the National Severe Storms Laboratory. References Brooks, H. E., C. A. Doswell, III, and M. P. Kay, (2003) Climatological estimates of local daily tornado probability, Wea. Forecasting, 18, 626-640.Source: https://www.climate.gov/maps-data/data-snapshots/data-source/historic-probability-severe-weather This upload includes two additional files:* Historic Probability of Severe Weather _NOAA Climate.gov.pdf is a screenshot of the main Climate.gov site for these snapshots (https://www.climate.gov/maps-data/data-snapshots/data-source/historic-probability-severe-weather )* Cimate_gov_ Data Snapshots.pdf is a screenshot of the data download page for the full-resolution files.

Local Climatological Data (LCD) contains summaries from major airport weather stations that include a daily account of temperature extremes, degree days, precipitation amounts and winds. Also included are the hourly precipitation amounts and abbreviated 3-hourly weather observations. This is the final quality controlled copy and generally has a one to two month time lag. The local climatological data annual file is produced from the National Weather Service (NWS) first and second order stations. These data are contained in the LCD monthly and annual publications. The monthly summaries include maximum, minimum, and average temperature, temperature departure from normal, dew point temperature, average station pressure, ceiling, visibility, weather type, wet bulb temperature, relative humidity, degree days (heating and cooling), daily precipitation, average wind speed, fastest wind speed/direction, sky cover, and occurrences of sunshine, snowfall and snow depth. The annual summary with comparative data contains monthly and annual averages of the above basic climatological data in the meteorological data for the current year section, a table of the normals, means, and extremes of these same data, and sequential table of monthly and annual values of average temperature, total precipitation, total snowfall, and total degree days. Also included is a station location table showing in detail a history of, and relative information about, changes in the locations and exposure of instruments. The NCDC also archives a Preliminary Local Climatological Data manuscript that contains similar information, but is not quality controlled.

Weather data were collected by the National Weather Service in International Falls, Minnesota. International Falls is about 80 miles from the SNF, but the weather data is representative of the area. Total solar insolation measurements were made at Fall Lake Dam in Winton, Minn. by Prof. Donald Baker of the Department of Soil Science at the University of Minnesota, St. Paul. Insolation values were measured using a Yellow Springs solar cell calibrated against an Eppley Pyranometer. This data set contains monthly summaries of the daily average temperature (minimum, maximum, average) and insolation for the years 1976-1986.

The global summaries data set contains a yearly (GSOY) resolution of meteorological elements (max temp, snow, etc) from 1763 to present with updates weekly. The major parameters are: monthly mean maximum, mean minimum and mean temperatures; monthly total precipitation and snowfall; departure from normal of the mean temperature and total precipitation; monthly heating and cooling degree days; number of days that temperatures and precipitation are above or below certain thresholds; and extreme daily temperature and precipitation amounts. The primary source data set source is the Global Historical Climatology Network (GHCN)-Daily Data set. The global summaries data set also contains a monthly (GSOM) resolution of meteorological elements. See associated resources for more information. This data is not to be confused with "GHCN-Monthly", "Annual Summaries" or "NCDC Summary of the Month". There are unique elements that are produced globally within the GSOM and GSOY data files. There are also bias corrected temperature data in GHCN-Monthly, which will not be available in GSOM and GSOY. The GSOM and GSOY data set is going to replace the legacy DSI-3220 and expand to include non-U.S. (a.k.a. global) stations. DSI-3220 only included National Weather Service (NWS) COOP Published, or "Published in CD", sites.

The NOAA Cooperative Observer Program (COOP) 15-Minute Precipitation Data consists of quality controlled precipitation amounts, which are measurements of 15 minute accumulation of precipitation, including rain and snow for approximately 2,000 observing stations around the country, and several U.S. territories in the Caribbean and Pacific operated or managed by the NOAA National Weather Service (NWS). Stations are primary, secondary, or cooperative observer sites that have the capability to measure precipitation at 15 minute intervals. This dataset contains 15-minute precipitation data (reported 4 times per hour, if precipitation occurred) for U.S. stations along with selected non-U.S. stations in U.S. territories and associated nations. It includes major city locations and many small town locations. Daily total precipitation is also included as part of the data record. The dataset period of record is from May 1970 to December 2013. The dataset is archived by the NOAA National Centers for Environmental Information (NCEI).

This data package contains locally verified daily meteorological observations from a NOAA National Weather Service station located at the USDA Jornada Experimental Range headquarters in southern New Mexico, USA. Daily data has been collected there by USDA staff since 1914 for minimum and maximum air temperature and daily accumulated precipitation using standard U.S. climatological service instrumentation and procedures. The included data were verified and transcribed directly from the original paper data sheets and have undergone quality control and assurance procedures different than those in place at NOAA. These data therefore differ from those directly downloadable from NOAA servers. Local verification and transcription of observations from the data sheets ceased in 2006 and data are now directly entered to the NOAA system. Therefore, this dataset is complete and will no longer be added to.All observations from this weather station have also undergone NOAA QA/QC procedures and those data are available by accessing the Jornada Experimental Range, NM US GHCN station through the National Climatic Data Center portal (https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USC00294426/detail - daily and monthly data are available).

CARICOOS is the observing arm of the Caribbean Regional Association for Integrated Coastal Ocean Observing (CaRA) http://cara.uprm.edu/. This effort, funded by the NOAA IOOS office http://ioos.noaa.gov/, is one of eleven coastal observing systems and regional associations which along with federal agencies constitute the national coastal component of the US Integrated Ocean Observing System. For more information on the regional associations, please visit http://www.ioosassociation.org This web page brings together coastal ocean data and forecasts from a variety of sources including satellites, ocean instruments and numerical models to give the user an integrated view of past, present and forecasted ocean conditions in the US Caribbean region. Data are provided online by a number of organizations including NOAA, NASA, ONR Universities and others to whom credit is given. Data and graphics, other than NOAA National Weather Service products, are presented as experimental products. CaRA assumes no responsibility for the validity of the data for planning or executing marine activities. For official information and forecasts on marine weather you should consult with the National Weather Service at http://www.nws.noaa.gov/ and its San Juan office at http://www.srh.noaa.gov/sju/

Quality Controlled Local Climatological Data (QCLCD) contains summaries from major airport weather stations that include a daily account of temperature extremes, degree days, precipitation amounts and winds. Also included are the hourly precipitation amounts and abbreviated 3-hourly weather observations. The source data is global hourly (DSI 3505) which includes a number of quality control checks. The local climatological data annual file is produced from the National Weather Service (NWS) first and second order stations. The monthly summaries include maximum, minimum, and average temperature, temperature departure from normal, dew point temperature, average station pressure, ceiling, visibility, weather type, wet bulb temperature, relative humidity, degree days (heating and cooling), daily precipitation, average wind speed, fastest wind speed/direction, sky cover, and occurrences of sunshine, snowfall and snow depth. The annual summary with comparative data contains monthly and annual averages of the above basic climatological data in the meteorological data for the current year section, a table of the normals, means, and extremes of these same data, and sequential table of monthly and annual values of average temperature, total precipitation, total snowfall, and total degree days. Also included is a station _location table showing in detail a history of, and relative information about, changes in the locations and exposure of instruments.

This dataset consists of Level 3 weather radar products collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska, Hawaii, U.S. territories and at military base sites. NEXRAD is a network of 160 high-resolution Doppler weather radars operated by the NOAA National Weather Service (NWS), the Federal Aviation Administration (FAA), and the U.S. Air Force (USAF). Doppler radars detect atmospheric precipitation and winds, which allow scientists to track and anticipate weather events, such as rain, ice pellets, snow, hail, and tornadoes, as well as some non-weather objects like birds and insects. NEXRAD stations use the Weather Surveillance Radar - 1988, Doppler (WSR-88D) system. This is a 10 cm wavelength (S-Band) radar that operates at a frequency between 2,700 and 3,000 MHz. The radar system operates in two basic modes: a slow-scanning Clear Air Mode (Mode B) for analyzing air movements when there is little or no precipitation activity in the area, and a Precipitation Mode (Mode A) with a faster scan for tracking active weather. The two modes employ nine Volume Coverage Patterns (VCPs) to adequately sample the atmosphere based on weather conditions. A VCP is a series of 360 degree sweeps of the antenna at pre-determined elevation angles and pulse repetition frequencies completed in a specified period of time. The radar scan times 4.5, 5, 6 or 10 minutes depending on the selected VCP. During 2008, the WSR-88D radars were upgraded to produce increased spatial resolution data, called Super Resolution. The earlier Legacy Resolution data provides radar reflectivity at 1.0 degree azimuthal by 1 km range gate resolution to a range of 460 km, and Doppler velocity and spectrum width at 1.0 degree azimuthal by 250 m range gate resolution to a range of 230 km. The upgraded Super Resolution data provides radar reflectivity at 0.5 degree azimuthal by 250 m range gate resolution to a range of 460 km, and Doppler velocity and spectrum width at 0.5 degree azimuthal by 250 m range gate resolution to a range of 300 km. Super resolution makes a compromise of slightly decreased noise reduction for a large gain in resolution. In 2010, the deployment of the Dual Polarization (Dual Pol) capability to NEXRAD sites began with the first operational Dual Pol radar in May 2011. Dual Pol radar capability adds vertical polarization to the previous horizontal radar waves, in order to more accurately discern the return signal. This allows the radar to better distinguish between types of precipitation (e.g., rain, hail and snow), improves rainfall estimates, improves data retrieval in mountainous terrain, and aids in removal of non-weather artifacts. The NEXRAD products are divided in two data processing levels. The lower Level 2 data are base products at original resolution. Level 2 data are recorded at all NWS and most USAF and FAA WSR-88D sites. From the Level 2 quantities, computer processing generates numerous meteorological analysis Level 3 products. The Level 3 data consists of reduced resolution, low-bandwidth, base products as well as many derived, post-processed products. Level 3 products are recorded at most U.S. sites, though non-US sites do not have Level 3 products. There are over 40 Level 3 products available from the NCDC. General products for Level 3 include the base and composite reflectivity, storm relative velocity, vertical integrated liquid, echo tops and VAD wind profile. Precipitation products for Level 3 include estimated ground accumulated rainfall amounts for one and three hour periods, storm totals, and digital arrays. Estimates are based on reflectivity to rainfall rate (Z-R) relationships. Overlay products for Level 3 are alphanumeric data that give detailed information on certain parameters for an identified storm cell. These include storm structure, hail index, mesocyclone identification, tornadic vortex signature, and storm tracking information. Radar messages for Level 3 are sent by the radar site to users in order to know more about the radar status and special product data. NEXRAD data are provided to the NOAA National Centers for Environmental Information (NCEI) for archiving and dissemination to users. Data coverage varies by station and ranges from May 1992 to 1 day from present. Most stations began observing in the mid-1990s, and most period of records are continuous.

This dataset consists of Level II weather radar data collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska, Hawaii, U.S. territories and at military base sites. NEXRAD is a network of 160 high-resolution Doppler weather radars operated by the NOAA National Weather Service (NWS), the Federal Aviation Administration (FAA), and the U.S. Air Force (USAF). Doppler radars detect atmospheric precipitation and winds, which allow scientists to track and anticipate weather events, such as rain, ice pellets, snow, hail, and tornadoes, as well as some non-weather objects like birds and insects. NEXRAD stations use the Weather Surveillance Radar - 1988, Doppler (WSR-88D) system. This is a 10 cm wavelength (S-Band) radar that operates at a frequency between 2,700 and 3,000 MHz. The radar system operates in two basic modes: a slow-scanning Clear Air Mode (Mode B) for analyzing air movements when there is little or no precipitation activity in the area, and a Precipitation Mode (Mode A) with a faster scan for tracking active weather. The two modes employ nine Volume Coverage Patterns (VCPs) to adequately sample the atmosphere based on weather conditions. A VCP is a series of 360 degree sweeps of the antenna at pre-determined elevation angles and pulse repetition frequencies completed in a specified period of time. The radar scan times 4.5, 5, 6 or 10 minutes depending on the selected VCP. The NEXRAD products are divided into multiple data processing levels. The lower Level II data contain the three meteorological base data quantities at original resolution: reflectivity, mean radial velocity, and spectrum width. With the advent of dual polarization beginning in 2011, additional base products of differential reflectivity, correlation coefficient and differential phase are available. Level II data are recorded at all NWS and most USAF and FAA WSR-88D sites. From the Level II quantities, computer processing generates numerous meteorological analysis Level 3 products. NEXRAD data are acquired by the NOAA National Centers for Environmental Information (NCEI) for archiving and dissemination to users. Data coverage varies by station and ranges from June 1991 to 1 day from present. Most stations began observing in the mid-1990s, and most period of records are continuous.

This layer is deprecated as of April 3, 2023. Use this layer as a replacement: https://noaa.maps.arcgis.com/home/item.html?id=b0cdf263cea24544b0da2fc00fb2b259This nowCOAST time-enabled map service provides maps of NOAA/National Weather Service RIDGE2 mosaics of base reflectivity images across the Continental United States (CONUS) as well as Puerto Rico, Hawaii, Guam and Alaska with a 2 kilometer (1.25 mile) horizontal resolution. The mosaics are compiled by combining regional base reflectivity radar data obtained from 158 Weather Surveillance Radar 1988 Doppler (WSR-88D) also known as NEXt-generation RADar (NEXRAD) sites across the country operated by the NWS and the Dept. of Defense and also from data from Terminal Doppler Weather Radars (TDWR) at major airports. The colors on the map represent the strength of the energy reflected back toward the radar. The reflected intensities (echoes) are measured in dBZ (decibels of z). The color scale is very similar to the one used by the NWS RIDGE2 map viewer. The radar data itself is updated by the NWS every 10 minutes during non-precipitation mode, but every 4-6 minutes during precipitation mode. To ensure nowCOAST is displaying the most recent data possible, the latest mosaics are downloaded every 5 minutes. For more detailed information about the update schedule, see: https://new.nowcoast.noaa.gov/help/#section=updateschedule

Background Information

Reflectivity is related to the power, or intensity, of the reflected radiation that is sensed by the radar antenna. Reflectivity is expressed on a logarithmic scale in units called dBZ. The "dB" in the dBz scale is logarithmic and is unit less, but is used only to express a ratio. The "z" is the ratio of the density of water drops (measured in millimeters, raised to the 6th power) in each cubic meter (mm^6/m^3). When the "z" is large (many drops in a cubic meter), the reflected power is large. A small "z" means little returned energy. In fact, "z" can be less than 1 mm^6/m^3 and since it is logarithmic, dBz values will become negative, as often in the case when the radar is in clear air mode and indicated by earth tone colors. dBZ values are related to the intensity of rainfall. The higher the dBZ, the stronger the rain rate. A value of 20 dBZ is typically the point at which light rain begins. The values of 60 to 65 dBZ is about the level where 3/4 inch hail can occur. However, a value of 60 to 65 dBZ does not mean that severe weather is occurring at that location. The best reflectivity is lowest (1/2 degree elevation angle) reflectivity scan from the radar. The source of the base reflectivity mosaics is the NWS Southern Region Radar Integrated Display with Geospatial Elements (RIDGE2).

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:

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.


  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.




  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

References

NWS, 2003: NWS Product Description Document for Radar Integrated Display with Geospatial Elements Version 2- RIDGE2, NWS/SRH, Fort Worth, Texas (Available at https://products.weather.gov/PDD/RIDGE_II_PDD_ver2.pdf). NWS, 2013: Radar Images for GIS Software (https://www.srh.noaa.gov/jetstream/doppler/gis.htm).

This Global Summaries dataset, known as GSOY for Yearly, contains a yearly resolution of meteorological elements from 1763 to present with updates applied weekly. The major parameters are: – average annual temperature, average annual minimum and maximum temperatures; total annual precipitation and snowfall; departure from normal of the mean temperature and total precipitation; heating and cooling degree days; number of days that temperatures and precipitation are above or below certain thresholds; extreme annual minimum and maximum temperatures; number of days with fog; and number of days with thunderstorms. The primary input data source is the Global Historical Climatology Network - Daily (GHCN-Daily) dataset. The Global Summaries datasets also include a monthly resolution of meteorological elements in the GSOM (for Monthly) dataset. See associated resources for more information. These datasets are not to be confused with "GHCN-Monthly", "Annual Summaries" or "NCDC Summary of the Month". There are unique elements that are produced globally within the GSOM and GSOY data files. There are also bias corrected temperature data in GHCN-Monthly, which are not available in GSOM and GSOY. The GSOM and GSOY datasets replace the legacy U.S. COOP Summaries (DSI-3220), and have been expanded to include non-U.S. (global) stations. U.S. COOP Summaries (DSI-3220) only includes National Weather Service (NWS) COOP Published, or "Published in CD", sites.

Map Information

This nowCOAST time-enabled map service provides maps depicting the geographic coverage of the latest NOAA/National Weather Service (NWS) WATCHES, WARNINGS, ADVISORIES, and STATEMENTS for long-duration hazardous weather, marine weather, hydrological, oceanographic, wildfire, air quality, and ecological conditions which may or are presently affecting inland, coastal, and maritime areas. A few examples include Gale Watch, Gale Warning, High Surf Advisory, High Wind Watch, Areal Flood Warning, Coastal Flood Watch, Winter Storm Warning, Wind Chill Advisory, Frost Advisory, Tropical Storm Watch, Red Flag Warning, Air Stagnation Warning, and Beach Hazards Statement. (A complete list is given in the Background Information section below.) The coverage areas of these products are usually defined by county or sub-county boundaries. The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at weather.gov. The NWS products for long-duration hazardous conditions are updated in the nowCOAST map service approximately every 10 minutes. For more detailed information about the update schedule, please see: http://new.nowcoast.noaa.gov/help/#section=updateschedule.

Background Information

NWS watches depict the geographic areas where the risk of hazardous weather or hydrologic events has increased significantly, but their occurrence, location, and/or timing is still uncertain. A warning depicts where a hazardous weather or hydrologic event is occurring, is imminent, or has a very high probability of occurring. A warning is used for conditions posing a threat to life or property. Advisories indicates where special weather conditions are occurring, imminent, or has a very high probability of occurring but are less serious than a warning. They are for events that may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property. Statements usually contain updated information on a warning and to let the public know when a warning is no longer in effect. All of these products are issued by the NWS regional Weather Forecast Offices (WFO).

NWS watches, warnings, and advisories (WWA) are organized on nowCOAST's map viewer and map services by hazardous conditions/threats groups and then by the geographic area (i.e. coastal & inland, immediate coast or maritime) that the WWA product is targeted for.

  High Wind Hazards (Associated with Non-Tropical & Tropical Cyclones)


      Maritime Areas

        Brisk Wind Advisory
        Small Craft Advisory
        Small Craft Advisory for Winds
        Gale Watch
        Gale Warning
        Storm Watch
        Storm Warning
        Hurricane Force Wind Watch
        Hurricane Force Wind Warning
        Tropical Storm Watch
        Tropical Storm Warning
        Hurricane Watch
        Hurricane Warning



      Coastal & Inland Areas

        High Wind Watch
        Wind Advisory
        Lake Wind Advisory
        High Wind Warning
        Tropical Storm Watch
        Tropical Storm Warning
        Hurricane Watch
        Hurricane Warning





  Hazardous Seas, Surf, and Beach Conditions


      Maritime Areas

        Small Craft Advisory for Hazardous Seas
        Small Craft Advisory for Rough Bar
        Hazardous Seas Watch
        Hazardous Seas Warning



      Immediate Coast

        Beach Hazards Statement
        High Surf Advisory
        High Surf Warning 
        Low Water Advisory
        Rip Current Statement





  Flooding Hazards


      Coastal Areas

        Coastal Flood Statement
        Coastal Flood Watch
        Coastal Flood Advisory
        Coastal Flood Warning
        Lakeshore Flood Watch
        Lakeshore Flood Advisory
        Lakeshore Flood Warning
        Lakeshore Flood Statement
        Tsunami Watch
        Tsunami Warning



      Inland Areas

        Flood Watch (Point) (also called River Flood Watch)
        Flood Watch (Areal)
        Flood Advisory (Point) (also called River Flood Advisory)
        Flood Advisory (Areal)
        Flood Warning (Point) (also called River Flood Warning)
        Flood Warning (Areal)
        Hydrologic Outlook
        Hydrologic Statement





  Reduced Visibility Hazards


      Maritime Areas

        Dense Fog Advisory



      Coastal & Inland Areas

        Ashfall Advisory
        Blowing Dust Advisory
        Dust Storm Warning
        Dense Fog Advisory
        Dense Smoke Advisory





  Freezing Spray Hazards

    Maritime Areas

        Heavy Freezing Spray Watch
        Freezing Spray Advisory
        Heavy Freezing Spray Advisory





  Snow, Sleet, Freezing Rain, and Freezing Fog Hazards


      Coastal & Inland Areas

        Blizzard Watch
        Blizzard Warning
        Freezing Fog Advisory
        Freezing Rain Advisory
        Ice Storm Warning
        Lake-Effect Snow Watch
        Lake-Effect Snow Advisory
        Lake-Effect Snow Warning
        Winter Storm Watch
        Winter Weather Advisory
        Winter Storm Warning





  Cold and Heat Hazards


      Coastal & Inland Areas

        Excessive Cold Watch
        Excessive Cold Warning
        Excessive Heat Watch
        Heat Advisory
        Excessive Heat Warning
        Frost Advisory
        Freeze Watch
        Freeze Warning
        Wind Chill Advisory
        Wind Chill Warning





  Critical Wildfire Conditions


      Coastal & Inland Areas

        Fire Weather Watch
        Red Flag Warning





  Unhealthy Air Quality


      Coastal & Inland Areas

        Air Stagnation Advisory
        Air Quality Alerts from states are NOT available

For descriptions of individual NWS watches, warnings, and advisories please see Section 2 of the NWS Reference Guide available at http://www.nws.noaa.gov/om/guide/Section2.pdf

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:

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.


  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.




  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

References

NWS, 2006: NWS Instructions 10-313, WFO Severe Weather Products Specification, NWS, Silver Spring, MD. NWS, 2007: NWS Instructions 10-320, Coastal/Lakeshore Hazard Services, NWS, Silver Spring, MD. NWS, 2007: NWS Instructions 10-922, Weather Forecast Office Hydrologic Products Specification, NWS, Silver Spring, MD. NWS, 2008: NWS Instructions 10-301, Marine and Coastal Services Abbreviations and Definitions, NWS, Silver Spring, MD. NWS, 2010: NWS Instructions 10-519, WFO Air Quality Products Specification, NWS, Silver Spring, MD. NWS, 2011: NWS Products and Services Reference Guidebook, NWS/Office of Climate, Water, and Weather Services, Silver Spring, MD. NWS,

When severe weather occurs in the United States, there are networks of humans and sensors that observe and report the events and their details to the National Weather Service. These storm reports are aggregated and archived by NOAA's National Centers for Environmental Information. With over 1.7 million records over 70 years, the Storm Events Database is the most comprehensive, official record of severe weather in the U.S. This layer is a simplified version of the full database, providing information on:DateLocationEvent TypeNumber of injuries and deathsEstimated property damageEvent/episode summariesUse the NOAA Storm Events Database Explorer ArcGIS Dashboard for a more interactive data exploration. Known Data Quality Issue: approximately 650,000 of the 1.71 million features do not include latitude or longitude values in the original NOAA data source. To address these issues in the 2021 data update, the following has been done:Use the county and state fields the geolocate unknown locations using the ArcGIS World Geocoding Service. These events will all appear at the county centroid. There are a total of 646,039 records in this category. The field LatLon Known describes if an original geolocation was provided (Yes) or if it was generated per above (No).Marine (CZ_Type = M) locations without a known lat/lon were not included. There are a total of 3,987 records in this category. For related archives of weather information, please see the Windstorm Points and Paths, Hailstorm Points and Paths, and Historical Hurricane layers.Data caveatsPer NCEI, the "National Weather Service receives their information from a variety of sources, which include but are not limited to: county, state and federal emergency management officials, local law enforcement officials, skywarn spotters, NWS damage surveys, newspaper clipping services, the insurance industry and the general public, among others." However, these sources are all population-dependent, and many severe weather events are assumed to not be reported in areas of low population. Not only does this bias occur across space, but also across time as many areas had lower populations in the mid-20th Century, and more advanced networks and reporting methods have evolved with technology.