This record is for Approval for Access product AfA054 Flood Warning Areas. These are geographical areas where we expect flooding to occur and where we provide a Flood Warning Service. They generally contain properties that are expected to flood from rivers or the sea and in some areas, from groundwater. Specifically, Flood Warning Areas define locations within the Flood Warning Service Limit that represent a discrete community at risk of flooding.

Flood Warnings are issued when flooding is expected to occur, Severe Flood Warnings are issued to similar areas when there is a danger to life or widespread disruption is expected.

INFORMATION WARNING: Groundwater flood warning areas are property based, usually containing a discrete urban area, suburb, city, village, or hamlet and were created in various ways. In general specialists used the national groundwater dataset, historical maps, bedrock geology and records of properties affected by groundwater flooding in the past to create the groundwater flood warning areas. Additional data sources, including groundwater susceptibility maps, borehole data, local modelling and LiDAR may also have been used depending on the location of the area.

This dataset was last updated on July 9th 2025.

This record is for Approval for Access product AfA136. Flood Warnings are provided by the constant monitoring of stations and forecasting flooding from rivers or the sea:

• Severe Flood Warning: Severe flooding. Danger to life.
• Flood Warning: Flooding is expected. Immediate action required.
• Flood Alert: Flooding is possible. Be prepared.
• Warning no longer in force: Flood warnings and flood alerts that have been removed in the last 24 hours.

Flood Warnings are available on our website and as a live feed. The live feed provides a summary of flood warnings (Alert, Warning and Severe) that have been issued and are currently in force. The Flood Warnings live feed provides the current status of each flood alert and flood warning area that is in force in England. This data is refreshed every minute within the Environment Agency and presented for external users at 5 minutes intervals. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.

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. The coverage areas of these products are usually defined by county or sub-county boundaries, but for simplicity and performance reasons, adjacent WWAs of the same type, issuance, and expiration are depicted in this service as unified (merged/dissolved) polygons in the layers indicated with the suffix "(Dissolved Polygons)". However, a set of equivalent layers containing the original individual zone geometries are also included for querying purposes, and are indicated with the suffix "(Zone Polygons)". Corresponding zone polygon and dissolved polygon layers are matched together in group layers for each WWA category. The zone polygon layers are included in this service only to support query/identify operations (e.g., in order to retrieve the original zone geometry or other attributes such as a URL to the warning text bulletin) and thus will not be drawn when included in a normal map image request. Thus, the dissolved polygon layers should be used when requesting a map image (e.g. WMS GetMap or ArcGIS REST export operations), while the zone polygon layers should be used when performing a query (e.g. WMS GetFeatureInfo or ArcGIS REST query or identify operations). The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at http://www.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 layer update frequency and timing, please reference the nowCOAST™ Dataset Update Schedule. 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 indicate where special weather conditions are occurring, imminent, or have 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, could lead to situations that may threaten life and/or property. Statements usually contain updated information on a warning and are used to let the public know when a warning is no longer in effect. NWS issues over 75 different types of watches, warnings, and advisories (WWAs). WWAs are issued by the NWS regional Weather Forecast Offices (WFOs) and also the NWS Ocean Prediction Center, National Hurricane Center, Central Pacific Hurricane Center, and Storm Prediction Center. The NWS WWAs are organized on the nowCOAST™ map viewer and within this map service by hazardous condition/threat layer groups and then by the geographic area (i.e. coastal & inland, immediate coast or maritime) for which the WWA product is targeted. This was done to allow users to select WWAs for hazardous conditions that are important to their operations or activities. Please note that the Tropical Storm and Hurricane Warnings are provided in both the High Wind Hazards: Maritime Areas and Coastal & Inland Areas layer groups and the Flooding Hazards: Coastal Areas layer group. These warnings are included in the Flooding Hazards/Coastal Areas layer group because the NWS uses those warnings to inform the public that tropical storm or hurricane winds may be accompanied by significant coastal flooding but below the thresholds required for the issuance of a storm surge warning. In addition, a tropical storm or hurricane warning may remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though the winds may be less than hurricane or tropical storm force. The NWS does not issue a Coastal Flood Warning or Advisory when a tropical storm or hurricane warning is in effect; however that does not mean that there is not a significant coastal flooding threat. 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 Storm Surge Watch Storm Surge Warning Tsunami Watch Tsunami Warning Tropical Storm Warning Hurricane 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 Ashfall Warning Blowing Dust Advisory Blowing Dust 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 service 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. In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service. 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. This service is configured with time coverage support, meaning that the service will always return the most relevant available data, if any, to the specified time value. For example, if the service contains data valid today at 12:00 and 12:10 UTC, but a map request specifies a time value of today at 12:07 UTC, the data valid at 12:10 UTC will be returned to the user. This behavior allows more flexibility for users, especially when displaying multiple time-enabled layers together despite slight differences in temporal resolution or update frequency. When interacting with this time-enabled service, only a single instantaneous time value should be specified in each request. If instead a time range is specified in a request (i.e. separate start time and end time values are given), the data returned may be different than what was intended. Care must be taken to ensure the time value specified in each request falls within the current time coverage of the service. Because this service is frequently updated as new data becomes available, the user must periodically determine the service's time extent. However, due to software limitations, the time extent of the service and

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. The coverage areas of these products are usually defined by county or sub-county boundaries, but for simplicity and performance reasons, adjacent WWAs of the same type, issuance, and expiration are depicted in this service as unified (merged/dissolved) polygons in the layers indicated with the suffix "(Dissolved Polygons)". However, a set of equivalent layers containing the original individual zone geometries are also included for querying purposes, and are indicated with the suffix "(Zone Polygons)". Corresponding zone polygon and dissolved polygon layers are matched together in group layers for each WWA category. The zone polygon layers are included in this service only to support query/identify operations (e.g., in order to retrieve the original zone geometry or other attributes such as a URL to the warning text bulletin) and thus will not be drawn when included in a normal map image request. Thus, the dissolved polygon layers should be used when requesting a map image (e.g. WMS GetMap or ArcGIS REST export operations), while the zone polygon layers should be used when performing a query (e.g. WMS GetFeatureInfo or ArcGIS REST query or identify operations). The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at http://www.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 layer update frequency and timing, please reference the nowCOAST™ Dataset Update Schedule. 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 indicate where special weather conditions are occurring, imminent, or have 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, could lead to situations that may threaten life and/or property. Statements usually contain updated information on a warning and are used to let the public know when a warning is no longer in effect. NWS issues over 75 different types of watches, warnings, and advisories (WWAs). WWAs are issued by the NWS regional Weather Forecast Offices (WFOs) and also the NWS Ocean Prediction Center, National Hurricane Center, Central Pacific Hurricane Center, and Storm Prediction Center. The NWS WWAs are organized on the nowCOAST™ map viewer and within this map service by hazardous condition/threat layer groups and then by the geographic area (i.e. coastal & inland, immediate coast or maritime) for which the WWA product is targeted. This was done to allow users to select WWAs for hazardous conditions that are important to their operations or activities. Please note that the Tropical Storm and Hurricane Warnings are provided in both the High Wind Hazards: Maritime Areas and Coastal & Inland Areas layer groups and the Flooding Hazards: Coastal Areas layer group. These warnings are included in the Flooding Hazards/Coastal Areas layer group because the NWS uses those warnings to inform the public that tropical storm or hurricane winds may be accompanied by significant coastal flooding but below the thresholds required for the issuance of a storm surge warning. In addition, a tropical storm or hurricane warning may remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though the winds may be less than hurricane or tropical storm force. The NWS does not issue a Coastal Flood Warning or Advisory when a tropical storm or hurricane warning is in effect; however that does not mean that there is not a significant coastal flooding threat. 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 Storm Surge Watch Storm Surge Warning Tsunami Watch Tsunami Warning Tropical Storm Warning Hurricane 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 Ashfall Warning Blowing Dust Advisory Blowing Dust 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 service 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. In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service. 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. This service is configured with time coverage support, meaning that the service will always return the most relevant available data, if any, to the specified time value. For example, if the service contains data valid today at 12:00 and 12:10 UTC, but a map request specifies a time value of today at 12:07 UTC, the data valid at 12:10 UTC will be returned to the user. This behavior allows more flexibility for users, especially when displaying multiple time-enabled layers together despite slight differences in temporal resolution or update frequency. When interacting with this time-enabled service, only a single instantaneous time value should be specified in each request. If instead a time range is specified in a request (i.e. separate start time and end time values are given), the data returned may be different than what was intended. Care must be taken to ensure the time value specified in each request falls within the current time coverage of the service. Because this service is frequently updated as new data becomes available, the user must periodically determine the service's time extent. However, due to software limitations, the time extent of the service and

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.

The coverage areas of these products are usually defined by county or sub-county boundaries, but for simplicity and performance reasons, adjacent WWAs of the same type, issuance, and expiration are depicted in this service as unified (merged/dissolved) polygons in the layers indicated with the suffix "(Dissolved Polygons)". However, a set of equivalent layers containing the original individual zone geometries are also included for querying purposes, and are indicated with the suffix "(Zone Polygons)". Corresponding zone polygon and dissolved polygon layers are matched together in group layers for each WWA category. The zone polygon layers are included in this service only to support query/identify operations (e.g., in order to retrieve the original zone geometry or other attributes such as a URL to the warning text bulletin) and thus will not be drawn when included in a normal map image request. Thus, the dissolved polygon layers should be used when requesting a map image (e.g. WMS GetMap or ArcGIS REST export operations), while the zone polygon layers should be used when performing a query (e.g. WMS GetFeatureInfo or ArcGIS REST query or identify operations).

The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at http://www.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 layer update frequency and timing, please reference the
nowCOAST™ Dataset Update Schedule.

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 indicate where special weather conditions are occurring, imminent, or have 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, could lead to situations that may threaten life and/or property. Statements usually contain updated information on a warning and are used to let the public know when a warning is no longer in effect. NWS issues over 75 different types of watches, warnings, and advisories (WWAs). WWAs are issued by the NWS regional Weather Forecast Offices (WFOs) and also the NWS Ocean Prediction Center, National Hurricane Center, Central Pacific Hurricane Center, and Storm Prediction Center.

The NWS WWAs are organized on the nowCOAST™ map viewer and within this map service by hazardous condition/threat layer groups and then by the geographic area (i.e. coastal & inland, immediate coast or maritime) for which the WWA product is targeted. This was done to allow users to select WWAs for hazardous conditions that are important to their operations or activities.

Please note that the Tropical Storm and Hurricane Warnings are provided in both the High Wind Hazards: Maritime Areas and Coastal & Inland Areas layer groups and the Flooding Hazards: Coastal Areas layer group. These warnings are included in the Flooding Hazards/Coastal Areas layer group because the NWS uses those warnings to inform the public that tropical storm or hurricane winds may be accompanied by significant coastal flooding but below the thresholds required for the issuance of a storm surge warning. In addition, a tropical storm or hurricane warning may remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though the winds may be less than hurricane or tropical storm force. The NWS does not issue a Coastal Flood Warning or Advisory when a tropical storm or hurricane warning is in effect; however that does not mean that there is not a significant coastal flooding threat.

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
   Storm Surge Watch
   Storm Surge Warning
   Tsunami Watch
   Tsunami Warning
   Tropical Storm Warning
   Hurricane 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
   Ashfall Warning
   Blowing Dust Advisory
   Blowing Dust 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 service 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.

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

This particular service can be queried with or without the use of a time component. If the time parameter

This record is for Approval for Access product AfA054 Flood Warning Areas are geographical areas where we expect flooding to occur and where we provide a Flood Warning Service. They generally contain properties that are expected to flood from rivers or the sea and in some areas, from groundwater. Specifically, Flood Warning Areas define locations within the Flood Warning Service Limit that represent a discrete community at risk of flooding. A discrete community is a recognised and named geographical community, which can be an urban area, a significant suburb of a large city or a village or a hamlet. The purpose of Flood Warnings is to alert people that flooding is expected and they should take action to protect themselves and their property. Flood Warnings are issued when flooding is expected to occur, Severe Flood Warnings are issued to similar areas when there is a danger to life or widespread disruption is expected. INFORMATION WARNING: Groundwater flood warning areas are properties based, usually containing a discrete urban area, suburb, city, village or hamlet and were created in various ways. In general technical specialists used the national groundwater dataset, historical maps, bedrock geology and records of properties affected by groundwater flooding in the past to create the groundwater flood warning areas. Additional data sources, including groundwater susceptibility maps, borehole data, local modelling and LiDAR may also have been used depending on the location of the area. The triggers for Flood Warnings for groundwater flooding are based on actual observed groundwater levels. There are currently no flood risk maps for groundwater so our flood warning areas for groundwater tend to cover properties which we know have been flooded by groundwater in the past. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.

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. The coverage areas of these products are usually defined by county or sub-county boundaries, but for simplicity and performance reasons, adjacent WWAs of the same type, issuance, and expiration are depicted in this service as unified (merged/dissolved) polygons in the layers indicated with the suffix "(Dissolved Polygons)". However, a set of equivalent layers containing the original individual zone geometries are also included for querying purposes, and are indicated with the suffix "(Zone Polygons)". Corresponding zone polygon and dissolved polygon layers are matched together in group layers for each WWA category. The zone polygon layers are included in this service only to support query/identify operations (e.g., in order to retrieve the original zone geometry or other attributes such as a URL to the warning text bulletin) and thus will not be drawn when included in a normal map image request. Thus, the dissolved polygon layers should be used when requesting a map image (e.g. WMS GetMap or ArcGIS REST export operations), while the zone polygon layers should be used when performing a query (e.g. WMS GetFeatureInfo or ArcGIS REST query or identify operations). The colors used to identify the different watches, advisories, warnings, and statements are the same colors used by the NWS on their map at http://www.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 layer update frequency and timing, please reference the nowCOAST™ Dataset Update Schedule. 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 indicate where special weather conditions are occurring, imminent, or have 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, could lead to situations that may threaten life and/or property. Statements usually contain updated information on a warning and are used to let the public know when a warning is no longer in effect. NWS issues over 75 different types of watches, warnings, and advisories (WWAs). WWAs are issued by the NWS regional Weather Forecast Offices (WFOs) and also the NWS Ocean Prediction Center, National Hurricane Center, Central Pacific Hurricane Center, and Storm Prediction Center. The NWS WWAs are organized on the nowCOAST™ map viewer and within this map service by hazardous condition/threat layer groups and then by the geographic area (i.e. coastal & inland, immediate coast or maritime) for which the WWA product is targeted. This was done to allow users to select WWAs for hazardous conditions that are important to their operations or activities. Please note that the Tropical Storm and Hurricane Warnings are provided in both the High Wind Hazards: Maritime Areas and Coastal & Inland Areas layer groups and the Flooding Hazards: Coastal Areas layer group. These warnings are included in the Flooding Hazards/Coastal Areas layer group because the NWS uses those warnings to inform the public that tropical storm or hurricane winds may be accompanied by significant coastal flooding but below the thresholds required for the issuance of a storm surge warning. In addition, a tropical storm or hurricane warning may remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though the winds may be less than hurricane or tropical storm force. The NWS does not issue a Coastal Flood Warning or Advisory when a tropical storm or hurricane warning is in effect; however that does not mean that there is not a significant coastal flooding threat. 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 Storm Surge Watch Storm Surge Warning Tsunami Watch Tsunami Warning Tropical Storm Warning Hurricane 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 Ashfall Warning Blowing Dust Advisory Blowing Dust 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 service 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. In addition to ArcGIS Server REST access, time-enabled OGC WMS 1.3.0 access is also provided by this service. 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. This service is configured with time coverage support, meaning that the service will always return the most relevant available data, if any, to the specified time value. For example, if the service contains data valid today at 12:00 and 12:10 UTC, but a map request specifies a time value of today at 12:07 UTC, the data valid at 12:10 UTC will be returned to the user. This behavior allows more flexibility for users, especially when displaying multiple time-enabled layers together despite slight differences in temporal resolution or update frequency. When interacting with this time-enabled service, only a single instantaneous time value should be specified in each request. If instead a time range is specified in a request (i.e. separate start time and end time values are given), the data returned may be different than what was intended. Care must be taken to ensure the time value specified in each request falls within the current time coverage of the service. Because this service is frequently updated as new data becomes available, the user must periodically determine the service's time extent. However, due to software limitations, the time extent of the service and

This spatial Flood Warning Areas dataset are geographical areas where NRW expect flooding to occur and where NRW provide a Flood Warning Service.

Flood Warning Areas generally contain properties that are expected to flood from rivers or the sea. Specifically, Flood Warning Areas define locations within the Flood Warning Service Limit that represent a discrete community at risk of flooding. A discrete community is a recognised and named geographical community, which can be an urban area, a significant suburb of a large city or a village or a hamlet.

The purpose of Flood Warnings is to alert people that flooding is expected and they should take action to protect themselves and their property. An online viewable version of this dataset is available here https://naturalresources.wales/our-evidence-and-reports/maps/flood-risk-map/?lang=en

For each reported flash flood event, the flash flood warning lead-time is the difference in minutes between the issuance of a flash flood warning and the onset of a geographically corresponding flash flood event. The lead times for all flash flood events, within the United States and territories served by the National Weather Service, are averaged to calculate the national average flash flood warning lead-time metric for a given fiscal year. This average includes all warned events with zero lead times and all unwarned events. Historically, flash flood warnings were issued and verified on a countywide basis. Starting in FY 2010, the storm-based warnings were implemented with verification based solely for the areas impacted by the warning and event.

Flood Warnings are issued by the Bureau to advise that flooding is occurring or expected to occur in a geographical area based on defined criteria. Flood Warning severity is displayed for each …Show full descriptionFlood Warnings are issued by the Bureau to advise that flooding is occurring or expected to occur in a geographical area based on defined criteria. Flood Warning severity is displayed for each sub-catchment, identified by the highest/worst classification of forecast severity (i.e. minor, moderate or major) at a forecast site within a sub-catchment. Generalised Flood Warnings may also be issued when there is no defined flood warning service, low amounts of data available or in the developing stages of a flood event. Final severity is displayed for the final issue of a Flood Warning. Flood Warning areas are areas that are at risk of the impacts of flooding (eg inundation of low lying areas). Flood Warning areas do not represent the current or forecast flood extent. Flood Warning areas are not defined for all parts of Australia. The flood forecasting and warning service uses rainfall and streamflow observations, numerical weather predictions and hydrologic models to forecast and warn for possible flood events. Flood warnings, which are issued by each Australian State/Territory have been combined into a national product for Web Map Service and Web Feature Service layers. Please note, flood warnings for the Melbourne Metropolitan and the South Australia section of the River Murray are issued on behalf of Melbourne Water and Department of Environment, Water and Natural Resources respectively. These products are text based format and as such are not available as a WMS.

Dataset shows the number of registrations for the flood warning system (FWS) by target area (flood warning and flood alert areas). The dataset includes figures for publically registerable live flood warning and flood alert target areas in England only. Data for all target areas with 10 or less properties will appear as blank - this is to protect the anonymity of customers in those target areas.

This feature service depicts the National Weather Service (NWS) watches, warnings, and advisories within the United States. Watches and warnings are classified into 43 categories. Those 43 categories have been filtered to just coastal watches, warnings, and advisories: coastal flooding, hurricanes, tropical storms. A warning is issued when a hazardous weather or hydrologic event is occurring, imminent or likely. A warning means weather conditions pose a threat to life or property. People in the path of the storm need to take protective action.A watch is used when the risk of a hazardous weather or hydrologic event has increased significantly, but its occurrence, location or timing is still uncertain. It is intended to provide enough lead time so those who need to set their plans in motion can do so. A watch means that hazardous weather is possible. People should have a plan of action in case a storm threatens, and they should listen for later information and possible warnings especially when planning travel or outdoor activities.An advisory is issued when a hazardous weather or hydrologic event is occurring, imminent or likely. Advisories are for less serious conditions than warnings, that cause significant inconvenience and if caution is not exercised, could lead to situations that may threaten life or property.SourceNational Weather Service RSS-CAP Warnings and Advisories: Public AlertsNational Weather Service Boundary Overlays: AWIPS Shapefile DatabaseSample DataSee Sample Layer Item for sample data during Weather inactivity!Update FrequencyThe services is updated every 5 minutes using the Aggregated Live Feeds methodology.The overlay data is checked and updated daily from the official AWIPS Shapefile Database.Area CoveredUnited States and TerritoriesWhat can you do with this layer?Customize the display of each attribute by using the Change Style option for any layer.Query the layer to display only specific types of weather watches and warnings.Add to a map with other weather data layers to provide insight on hazardous weather events.Use ArcGIS Online analysis tools, such as Enrich Data, to determine the potential impact of weather events on populations.

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,

Flood Alert Areas are geographical areas where it is possible for flooding to occur from rivers or the sea. A single Flood Alert Area may cover the floodplain within the Flood Warning Service Limit of multiple catchments of similar characteristics containing a number of Flood Warning Areas. A Flood Alert Area may also match that of a corresponding Flood Warning Area and warn for the possibility of flooding in that area. In some coastal locations a Flood Alert may be issued for spray or overtopping and be defined by a stretch of coastline. Practical and administrative factors may also influence the exact extent of a Flood Alert Area. An online viewable version of the dataset is available here: https://naturalresources.wales/our-evidence-and-reports/maps/flood-risk-map/?lang=en

The Numerical Flash Flood Alert APP (NFFA APP) proudly supports the water science community across the United States by offering streamlined access to essential flood data from all USGS stations.

Accessing water data can sometimes be challenging. Our website is designed to provide quick and easy access to vital flood information for all USGS stations, helping professionals and communities stay informed and prepared. Here’s what you can find:

Action stage: This crucial threshold helps signal when it's time to start taking action in response to potential flooding. Basin Area: Measured in square kilometers, this gives you insights into the scale of the potential flood. Basin slope and stream length: These key geographical features provide critical information on water flow and flood potential. Flashiness metrics: These indicators measure the variability in historical streamflow at each station, using a color-coded system: red indicates low variability, green is medium, and blue signifies high variability. Technological Expertise To deliver state-of-the-art solutions, we leverage a comprehensive suite of advanced IT tools:

Hydraulic & Hydrologic Modeling: We utilize sophisticated tools such as HEC-HMS for hydrology, HEC-RAS for hydraulics, and EF5 for precision in flash flood simulation. Our models are crucial for designing effective flood warning systems, enhanced by real-time satellite data to monitor and predict flood events accurately. Water Resources Management: Our application of WEAP aids in sustainable water resources planning across sectors like agriculture, urban centers, and treatment facilities. This tool supports our commitment to developing well-informed, sustainable management strategies through detailed numerical analysis. Pressurized Systems: Utilizing Pipe Flow Expert, we optimize systems for efficiency and sustainability, selecting the ideal pipes and pumps based on comprehensive hydrodynamic modeling. Data Analysis Software: We employ Python and R Studio for cutting-edge data analysis, allowing us to craft sophisticated algorithmic solutions that enhance our predictive capabilities and decision-making processes. GIS Software: Through ArcGIS and QGIS, we deliver intricate geographical mapping and spatial data analysis. These tools are integral to our comprehensive approach, offering crucial insights into the geographic dynamics of water flow and potential flood zones.

Continuously updated US flooding information from the National Weather Service shows observed flooding locations, current & forecast precipitation, and flood warning areas. The stream gauges and weather watches layers allow you to identify features to get specific information such as flooding height, weather related issue, and severity. For a map that focuses on more general weather reports and current radar, see our Severe Weather Map.

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.

Flood Warnings (short and long term): 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.

National rainfall, river level and tide gauges used in delivering the Bureau of Meteorology's flood warning service, along with flood watch & flood warning catchments.

These spatial datasets represent the Bureau of Meteorology's National rainfall gauge and river level gauge flood network, which are utilised for delivering flood warning services. Flood gauges are classified forecast, information, data and tide gauge locations. Also includes Bureau flood watch catchments and flood warning catchments.

Supporting datasets include Geofabric V3x, showing major rivers and all rivers, streams and creeks, as well as Local Government Areas.

Dataset shows flood warning areas within South Ribble

The National Weather Service issues warnings for severe weather that are imminent or actively occurring. This layer shows shorter-term warnings for the following events:Special Marine Warnings - potentially hazardous weather conditions of short duration (up to 2 hours) that may include sustained winds or gusts of 39 mph or greater, hail 0.75” or greater in diameter, or waterspouts.Severe Thunderstorm Warnings - storms with winds of 58 mph or higher or hail 1” or greater in diameter.Tornado Warnings - imminent or active tornados.Extreme Wind Warnings - surface winds of 115 mph or greater associated with non-convective, downslope, derecho, or sustained hurricane winds are expected to occur within one hour.Flash Flood Warnings - conditions are favorable for flash flooding. It does not mean that flash flooding will occur, but it is possible.SourceCurrent Warnings: https://www.weather.gov/source/crh/shapefiles/CurrentWarnings.tar.gzSample DataSee Sample Layer Item for sample data during Weather inactivity!Update FrequencyThe service is updated every 5 minutes using the Aggregated Live Feeds methodology.Area CoveredContiguous United StatesWhat can you do with this layer?Customize the display of each attribute by using the Change Style option for any layer.Query the layer to display only specific types of weather watches and warnings.Add to a map with other weather data layers to provide inside on hazardous weather events.Use ArcGIS Online analysis tools, such as Enrich Data, to determine the potential impact of weather events on populations.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!