This map is a view of current evacuations in California, using data processed by the Office of Emergency Services and the map published by the Department of Technology for use on the state geoportal. To access the raw data, as well as metadata for the data layers, please see the source data at https://california.maps.arcgis.com/home/item.html?id=15fb71971c7246338440d39b9f158bd7

Updated Frequency: 10 minutes

Status	Color Hex Value	Color Name	Color	Description
NORMAL	#FFFFFF	White		No active public safety incidents.
EVACUATION WARNING	#E5C447	Yellow		Potential threat to life and/or property. Those who require additional time to evacuate, and those with pets and livestock should leave now.
EVACUATION ORDER	#D37072	Red		Immediate threat to life. This is a lawful order to leave now. The area is lawfully closed to public access.

Inventory of Counties whose Evacuation Order information is publicly shared by Cal OES through the California Active Evacuation Zones feature service.

This feature service is an aggregation of multiple California County Evacuation Zone services, and Genasys. The schema used mirrors the Zonehaven Schema. This service is fully updated every 10 minutes. During the update, there may be a brief period (~1 min) where the service is rebuilding and not all features are visible.Updated Frequency: 10 minutesContact: gissupport@caloes.ca.govSymbologyStatusColor Hex ValueColor NameColorDescriptionNORMAL#FFFFFFWhiteNo active public safety incidents.EVACUATION WARNING#E5C447YellowPotential threat to life and/or property. Those who require additional time to evacuate, and those with pets and livestock should leave now.EVACUATION ORDER#D37072RedImmediate threat to life. This is a lawful order to leave now. The area is lawfully closed to public access.SHELTER IN PLACE#BF6ADCPurpleGo indoors. Shut and lock doors and windows. Prepare to self-sustain until further notice and/or contacted by emergency personnel for additional direction.CLEAR TO REPOPULATE#90D260GreenIt is now safe to return to your home post evacuation.ADVISORY#6A95CBBlueBe on alert and follow county recommendations.

Updated Frequency: 10 minutes

Status	Color Hex Value	Color Name	Color	Description
NORMAL	#FFFFFF	White		No active public safety incidents.
EVACUATION WARNING	#E5C447	Yellow		Potential threat to life and/or property. Those who require additional time to evacuate, and those with pets and livestock should leave now.
EVACUATION ORDER	#D37072	Red		Immediate threat to life. This is a lawful order to leave now. The area is lawfully closed to public access.

Inventory of Counties whose Evacuation Order information is publicly shared by Cal OES through the California Active Evacuation Zones feature service.

Source Item: https://calema.maps.arcgis.com/home/item.html?id=15fb71971c7246338440d39b9f158bd7The data for this feature service is derived from the CalOES feed indicated at the source item above, which compiles evacuation zone data from multiple local services into a single feed. Since the CalOES feed is a live service showing currently active evacuation orders and warnings, this historic feature service was developed by merging the backups of the live service run daily at 3AM Pacific Time. This database maintains all field headings, field values, and feature polygons of the original CalOES service while adding an EFFECTIVE_DATE_R9 date field to indicate the day and hour that the backup script was run. In order to isolate a specific period of active evacuations, apply a filter to the EFFECTIVE_DATE_R9 field.This service is currently in development. At this time it consists of evacuation data starting January 7th 2025 and is updated daily with the most recent daily backup.

These maps show predictions for the estimated maximum extent of inundation for a LOCAL Cascadia tsunami (YELLOW) for all of Oregon and Washington overlaid on Google Maps. For portions of the Oregon coast only (e.g. currently Bandon to OR/CA border and Cannon Beach), these maps show TWO inundation lines: the estimated maximum extent of inundation for a LOCAL Cascadia tsunami (YELLOW) and a DISTANT tsunami (ORANGE). The entire Pacific coast including Puget Sound, are vulnerable to DISTANT tsunamis even if not depicted on this map. Sections of the coast marked by diagonal lines are currently unmapped, but are also vulnerable to tsunamis - Be vigilant and know what to do when at the coast.

Produced collectively by geologic hazard mapping scientists, and emergency planning specialists from the California Geological Survey, the California Governor’s Office of Emergency Services, and local agencies, organizations, and other stakeholders. The tsunami hazard evacuation areas were developed for all populated areas at risk to tsunamis in California and are based on the tsunami hazard defined in the Tsunami Inundation Maps for Emergency Planning. While the State assisted in the development of the evacuation areas, local agencies, organizations, and other stakeholders made the final determination on the location and coverage of these evacuation areas as they will be used for evacuation planning at the community level.

This layer features tropical storm (hurricanes, typhoons, cyclones) tracks, positions, and observed wind swaths from the past hurricane season for the Atlantic, Pacific, and Indian Basins. These are products from the National Hurricane Center (NHC) and Joint Typhoon Warning Center (JTWC). They are part of an archive of tropical storm data maintained in the International Best Track Archive for Climate Stewardship (IBTrACS) database by the NOAA National Centers for Environmental Information.Data SourceNOAA National Hurricane Center tropical cyclone best track archive.Update FrequencyWe automatically check these products for updates every 15 minutes from the NHC GIS Data page.The NHC shapefiles are parsed using the Aggregated Live Feeds methodology to take the returned information and serve the data through ArcGIS Server as a map service.Area CoveredWorldWhat can you do with this layer?Customize the display of each attribute by using the ‘Change Style’ option for any layer.Run a filter to query the layer and display only specific types of storms or areas.Add to your map with other weather data layers to provide insight on hazardous weather events.Use ArcGIS Online analysis tools like ‘Enrich Data’ on the Observed Wind Swath layer to determine the impact of cyclone events on populations.Visualize data in ArcGIS Insights or Operations Dashboards.This map is provided for informational purposes and is not monitored 24/7 for accuracy and currency. Always refer to NOAA or JTWC sources for official guidance.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!

National Hurricane Center - National Storm Surge Hazard Maps - https://www.nhc.noaa.gov/nationalsurge/The SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model is a numerical model used by NWS to compute storm surge. Storm surge is defined as the abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Flooding from storm surge depends on many factors, such as the track, intensity, size, and forward speed of the hurricane and the characteristics of the coastline where it comes ashore or passes nearby. For planning purposes, the NHC uses a representative sample of hypothetical storms to estimate the near worst-case scenario of flooding for each hurricane category.This is version 3 of the NHC National Storm Surge Risk Maps. The updates in this version include data mapped to 10m DEMs for the US Gulf and East Coast. The following new regions have been added: Southern California (hurricane wind category 1 and 2 storms), Guam, American Samoa, and the Yucatan Peninsula for parts of Mexico, Belize, and Honduras. For simplicity, the tiled map services are published by hurricane wind category and all available mapped regions for that category are provided in that web map.The following areas are mapped in the hurricane wind Category 3 Maps:US Gulf and East CoastPuerto Rico and US Virgin IslandsHawaiiGuamAmerican SamoaHispaniolaYucatan Peninsula- parts of Mexico, Belize, Guatemala, and western HondurasSLOSH employs curvilinear polar, elliptical, and hyperbolic telescoping mesh grids to simulate the storm surge hazard. The spatial coverage for each SLOSH grid ranges from an area the size of a few counties to a few states. The resolution of individual grid cells within each basin ranges from tens to hundreds of meters to a kilometer or more. Sub-grid scale water features and topographic obstructions such as channels, rivers, and cuts and levees, barriers, and roads, respectively, are parameterized to improve the modeled water levels.The NHC provides two products based on hypothetical hurricanes: MEOWs and MOMs. MEOWs are created by computing the maximum storm surge resulting from up to 100,000 hypothetical storms simulated through each SLOSH grid of varying forward speed, radius of maximum wind, intensity (Categories 1-5), landfall location, tide level, and storm direction. A MEOW product is created for each combination of category, forward speed, storm direction, and tide level. SLOSH products exclude Category 5 storms north of the NC/VA border. SLOSH products only include hurricane wind Category 1-4 scenarios for Hawaii and hurricane wind category 1-2 scenarios for Southern California. For each storm combination, parallel storms make landfall in 5 to 10 mile increments along the coast within the SLOSH grid, and the maximum storm surge footprint from each simulation is composited, retaining the maximum height of storm surge in a given basin grid cell. These are called MEOWs and no single hurricane will produce the regional flooding depicted in the MEOWs. SLOSH model MOMs are an ensemble product of maximum storm surge heights. SLOSH MOMs are created for each storm category by retaining the maximum storm surge value in each grid cell for all the MEOWs, regardless of the forward speed, storm trajectory, or landfall location. SLOSH MOMs are available for mean tide and high tide scenarios and represent the near worst-case scenario of flooding under ideal storm conditions. A high tide initial water level was used for the storm surge hazard maps.This product uses the expertise of the NHC Storm Surge Unit to merge the operational SLOSH grids to build a seamless map of storm surge hazard scenarios using the MOM product. Each individual SLOSH grid for the Category 1-5 MOMs are merged into a single, seamless grid. The seamless grid is then resampled, interpolated, and processed with a DEM (Digital Elevation Model, i.e. topography) to compute the storm surge hazard above ground for each hurricane wind category. The SLOSH MOM storm surge hazard data used to create these maps are constrained by the extent of the SLOSH grids and users should be aware that risk due to storm surge flooding could extend beyond the areas depicted in these maps.Users of this hazard map should be aware that potential storm surge flooding is not depicted within some levee areas, such as the Hurricane & Storm Damage Risk Reduction System in Louisiana. These areas are highly complex and water levels resulting from overtopping are difficult to predict. Users are urged to consult local officials for flood risk inside these leveed areas. If applicable to the region displayed by the map, these leveed areas will be depicted with a black and white diagonal hatch pattern. Not all levee areas are included in this analysis - in particular, local features such as construction walls, levees, berms, pumping systems, or other mitigation systems found at the local level may not be included in this analysis. Additionally, some marshy or low lying areas are not mapped in this analysis.In locations that have a steep and narrow continental shelf, wave setup can be a substantial contributor to the total water level rise observed during a tropical cyclone. Wave setup is defined as the increase in mean water level due to momentum transfer to the water column by waves that are breaking or otherwise dissipating their energy. The following locations use SLOSH+Wave Setup simulations to create MEOW and MOM products that account for the increase in the mean water level due to wave setup: Puerto Rico, US Virgin Islands, Hawaii, Hispaniola, Guam, American Samoa, and Southern California. Through the USAID/WMO Coastal Inundation and Flooding Demonstration Project, these SLOSH storm surge risk products were created for the Island of Hispaniola.

Date of Image:9/4/2019Date of Next Image:UnknownSummary:The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory and California Institute of Technology in Pasadena, California, created this Damage Proxy Map (DPM) depicting areas of the Bahamas that are likely damaged (shown by red and yellow pixels) as a result of Hurricane Dorian that made a landfall as Category 5 storm Sunday (September 1) afternoon. The map was derived from synthetic aperture radar (SAR) data acquired around 7pm (local time) on September 2, 2019 by the European Union's Copernicus Sentinel-1 satellites operated by the European Space Agency (ESA). The pre-event images were taken before (August 21, 2019) and the post-event image was acquired a day after the hurricane's landfall.Suggested Use:The color variation from yellow to red indicates increasingly more significant ground surface change.This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas and flooded areas. For example, the scattered single colored pixels over vegetated areas may be false positives, and the lack of colored pixels over vegetated areas does not necessarily mean no damage.Satellite/Sensor:Synthetic Aperture Radar (SAR) on European Space Agency's (ESA) Copernicus Sentinel-1 satelliteResolution: 30 metersCredits:Contains modified Copernicus Sentinel data (2019) processed by the ARIA team at NASA-JPL and Caltech. This task was funded by NASA Disasters Program.For more information about ARIA, visit: http://aria.jpl.nasa.govFor more information about the EU’s Copernicus Programme, visit: https://www.copernicus.eu/enEsri REST Endpoint:See URL section on right side of pageWMS Endpoint: https://maps.disasters.nasa.gov/ags04/services/hurricane_dorian_2019/aria_dpm_sentinel1_20190904/ImageServer/WMSServer

Date of Image:9/2/2019Date of Next Image:UnknownSummary:The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory and California Institute of Technology in Pasadena, California, in collaboration with the Earth Observatory of Singapore (EOS), created this Flood Proxy Map depicting areas of the Bahamas that are likely flooded as a result of Hurricane Dorian that made a landfall as Category 5 storm Sunday (September 1) afternoon. The map was derived from synthetic aperture radar (SAR) data acquired around 7pm (local time) on September 2, 2019 by the Copernicus Sentinel-1 satellites operated by the European Space Agency (ESA).Suggested Usage:Potentially flooding is shown by blue pixels.This flood proxy map should be used as guidance to identify areas that are likely flooded, and may be less reliable over urban and vegetated areas.Satellite/Sensor:Synthetic Aperture Radar (SAR) on European Space Agency's (ESA) Copernicus Sentinel-1A satelliteResolution: 30 metersCredits:Contains modified Copernicus Sentinel data (2019) analyzed by the NASA-JPL/Caltech ARIA team. This task was carried out at JPL funded by NASA Disasters Program.Esri REST Endpoint:See URL section on right side of pageWMS Endpoint:https://maps.disasters.nasa.gov/ags03/services/hurricane_dorian_2019/aria_fpm_sentinel1_20190902/ImageServer/WMSServer

EmergencyMapBC is overseen by EmergencyInfoBC and serves as a general reference for current public safety conditions during emergencies. This application displays information related to emergencies in British Columbia from the Ministry of Emergency Management and Climate Readiness. EmergencyMapBC includes Evacuation Alert and Order layers that indicate which areas of BC have been issued an Evacuation Alert or Evacuation Order in response to a potential hazard. In addition, locations of Emergency Support Services Reception Centres are viewable, as well as flood watches and warnings issued by the Province of British Columbia. For more information on emergencies, please visit https://www.emergencyinfobc.gov.bc.ca/ .A GeoBC production in association with Emergency Management and Climate Readiness BC.BC Data Catalogue Metadata: https://catalogue.data.gov.bc.ca/dataset/70bb4164-b353-499f-91c6-7c5d65a73eedCOPYRIGHT | DISCLAIMER | PRIVACY | ACCESSIBILITY

Produced collectively by geologic hazard mapping scientists, and emergency planning specialists from the California Geological Survey, the California Governor’s Office of Emergency Services, and local agencies, organizations, and other stakeholders. The tsunami hazard areas were developed for all populated areas at risk to tsunamis in California and are based on the tsunami hazard defined in the Tsunami Inundation Maps for Emergency Planning. While the State assisted in the development of the evacuation areas, local agencies, organizations, and other stakeholders made the final determination on the location and coverage of these evacuation areas as they will be used for evacuation planning at the community level.

Produced collectively by tsunami modelers, geologic hazard mapping specialists, and emergency planning scientists from CGS, Cal OES, and the Tsunami Research Center at the University of Southern California, the tsunami inundation maps for California cover most residentially and transient populated areas along the state’s coastline. Coordinated by Cal OES, these official maps are developed for all populated areas at risk to tsunamis in California and represent a combination of the maximum considered tsunamis for each area.For more information please visit: Official Tsunami Inundation ZonesMap Disclaimer: These maps were prepared to assist cities and counties in identifying their tsunami hazard. They are intended for local jurisdictional, coastal evacuation planning uses only. These maps are not a legal documents and do not meet disclosure requirements for real estate transactions nor for any other regulatory purpose. The California Emergency Management Agency (CalEMA), the University of Southern California (USC), and the California Geological Survey (CGS) make no representation or warranties regarding the accuracy of this inundation map nor the data from which the map was derived. Neither the State of California nor USC shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of this map.

Produced collectively by geologic hazard mapping scientists, and emergency planning specialists from the California Geological Survey, the California Governor’s Office of Emergency Services, and local agencies, organizations, and other stakeholders. The tsunami hazard evacuation areas were developed for all populated areas at risk to tsunamis in California and are based on the tsunami hazard defined in the Tsunami Inundation Maps for Emergency Planning. While the State assisted in the development of the evacuation areas, local agencies, organizations, and other stakeholders made the final determination on the location and coverage of these evacuation areas as they will be used for evacuation planning at the community level.The hazard map is compiled with best currently available scientific information. The Tsunami Hazard Line represents an area that could be exposed to tsunami hazards during a tsunami event. The Tsunami Hazard Line includes tsunami model results that at a minimum represent inundation exceeding that of a 975-year average return period event. Please refer to the following websites for additional information on the construction and/or intended use of the Tsunami Hazard Line:California Geological Survey Tsunami Information: https://www.tsunami.ca.gov/California Governor’s Office of Emergency Services, Earthquake, Tsunami, and Volcano Program: https://www.caloes.ca.gov/cal-oes-divisions/earthquake-tsunami-volcano-programs/tsunami-about

This Layer is the layer that shows on the public website to show Evacuation Alerts, Orders and Rescinds.For more information on the Area's under Evacuation please visit www.cordemergency.ca

Date of Image:9/3/2021Date of Next Image:None ExpectedSummary:The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory and California Institute of Technology in Southern California, in collaboration with the Earth Observatory of Singapore (EOS), created this Damage Proxy Map (DPM) depicting areas that are likely damaged by the Hurricane Ida (August 29, 2021) in central and western Louisiana, United States. The map was derived from synthetic aperture radar (SAR) images on Sep 03, 2021 by the Copernicus Sentinel-1 satellites operated by the European Space Agency (ESA). The pre-event images were taken before (Aug 10, 2021 and Aug 22, 2021) the hurricane hit land. The image covers an area of 337 by 250 kilometers (210 by 155 miles. Each pixel measures about 30 meters across. Suggested Use:The color variation from yellow to red indicates increasingly more significant surface change. Preliminary validation was done by comparing with the Media reports. This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated or flooded areas. For example, the scattered colored pixels over vegetated areas and flooded fields may be false positives, and the lack of colored pixels over vegetated areas does not necessarily mean no damage. Some additional false positives in the middle of the image are likely due to the stitching of Sentinel-1 frames as a thin line running across the map at a ENE-WSW angle. This map is most sensitive to building damage, but small-scale change or partial structural damage may not be detected by this map. Satellite/Sensor:Copernicus Sentinel-1 Synthetic Aperture Radar (SAR)Resolution:30 metersCredits:Sentinel-1 data were accessed through the Copernicus Open Hub and the Alaska Satellite Facility server. The product contains modified Copernicus Sentinel data (2021), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team and EOS team. Part of the funding was provided by NASA's Earth Applied Sciences Disasters Program.For more information about ARIA, visit: http://aria.jpl.nasa.govFor more information about EOS, visit: http://earthobservatory.sgEsri REST Endpoint:See URL section on right side of pageWMS Endpoint:https://maps.disasters.nasa.gov/ags04/services/hurricane_ida_2021/aria_dpm_sentinel1_20210903/ImageServer/WMSServerData Download:https://aria-share.jpl.nasa.gov/20210829-Hurricane_Ida_USA/DPM/

The SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model is a numerical model used by NWS to compute storm surge. Storm surge is defined as the abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Flooding from storm surge depends on many factors, such as the track, intensity, size, and forward speed of the hurricane and the characteristics of the coastline where it comes ashore or passes nearby. For planning purposes, the NHC uses a representative sample of hypothetical storms to estimate the near worst-case scenario of flooding for each hurricane category.This is version 3 of the NHC National Storm Surge Risk Maps. The updates in this version include data mapped to 10m DEMs for the US Gulf and East Coast. The following new regions have been added: Southern California (hurricane wind category 1 and 2 storms), Guam, American Samoa, and the Yucatan Peninsula for parts of Mexico, Belize, and Honduras. For simplicity, the tiled map services are published by hurricane wind category and all available mapped regions for that category are provided in that web map.The following areas are mapped in the hurricane wind Category 1 Maps:US Gulf and East CoastPuerto Rico and US Virgin IslandsSouthern CaliforniaHawaiiGuamAmerican SamoaHispaniolaYucatan Peninsula- parts of Mexico, Belize, Guatemala, and western HondurasSLOSH employs curvilinear polar, elliptical, and hyperbolic telescoping mesh grids to simulate the storm surge hazard. The spatial coverage for each SLOSH grid ranges from an area the size of a few counties to a few states. The resolution of individual grid cells within each basin ranges from tens to hundreds of meters to a kilometer or more. Sub-grid scale water features and topographic obstructions such as channels, rivers, and cuts and levees, barriers, and roads, respectively, are parameterized to improve the modeled water levels.The NHC provides two products based on hypothetical hurricanes: MEOWs and MOMs. MEOWs are created by computing the maximum storm surge resulting from up to 100,000 hypothetical storms simulated through each SLOSH grid of varying forward speed, radius of maximum wind, intensity (Categories 1-5), landfall location, tide level, and storm direction. A MEOW product is created for each combination of category, forward speed, storm direction, and tide level. SLOSH products exclude Category 5 storms north of the NC/VA border. SLOSH products only include hurricane wind Category 1-4 scenarios for Hawaii and hurricane wind category 1-2 scenarios for Southern California. For each storm combination, parallel storms make landfall in 5 to 10 mile increments along the coast within the SLOSH grid, and the maximum storm surge footprint from each simulation is composited, retaining the maximum height of storm surge in a given basin grid cell. These are called MEOWs and no single hurricane will produce the regional flooding depicted in the MEOWs. SLOSH model MOMs are an ensemble product of maximum storm surge heights. SLOSH MOMs are created for each storm category by retaining the maximum storm surge value in each grid cell for all the MEOWs, regardless of the forward speed, storm trajectory, or landfall location. SLOSH MOMs are available for mean tide and high tide scenarios and represent the near worst-case scenario of flooding under ideal storm conditions. A high tide initial water level was used for the storm surge hazard maps.This product uses the expertise of the NHC Storm Surge Unit to merge the operational SLOSH grids to build a seamless map of storm surge hazard scenarios using the MOM product. Each individual SLOSH grid for the Category 1-5 MOMs are merged into a single, seamless grid. The seamless grid is then resampled, interpolated, and processed with a DEM (Digital Elevation Model, i.e. topography) to compute the storm surge hazard above ground for each hurricane wind category. The SLOSH MOM storm surge hazard data used to create these maps are constrained by the extent of the SLOSH grids and users should be aware that risk due to storm surge flooding could extend beyond the areas depicted in these maps.Users of this hazard map should be aware that potential storm surge flooding is not depicted within some levee areas, such as the Hurricane & Storm Damage Risk Reduction System in Louisiana. These areas are highly complex and water levels resulting from overtopping are difficult to predict. Users are urged to consult local officials for flood risk inside these leveed areas. If applicable to the region displayed by the map, these leveed areas will be depicted with a black and white diagonal hatch pattern. Not all levee areas are included in this analysis - in particular, local features such as construction walls, levees, berms, pumping systems, or other mitigation systems found at the local level may not be included in this analysis. Additionally, some marshy or low lying areas are not mapped in this analysis.In locations that have a steep and narrow continental shelf, wave setup can be a substantial contributor to the total water level rise observed during a tropical cyclone. Wave setup is defined as the increase in mean water level due to momentum transfer to the water column by waves that are breaking or otherwise dissipating their energy. The following locations use SLOSH+Wave Setup simulations to create MEOW and MOM products that account for the increase in the mean water level due to wave setup: Puerto Rico, US Virgin Islands, Hawaii, Hispaniola, Guam, American Samoa, and Southern California. Through the USAID/WMO Coastal Inundation and Flooding Demonstration Project, these SLOSH storm surge risk products were created for the Island of Hispaniola.View Dataset on the Gateway

DescriptionNational Hurricane Center - National Storm Surge Hazard Maps - https://www.nhc.noaa.gov/nationalsurge/The SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model is a numerical model used by NWS to compute storm surge. Storm surge is defined as the abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Flooding from storm surge depends on many factors, such as the track, intensity, size, and forward speed of the hurricane and the characteristics of the coastline where it comes ashore or passes nearby. For planning purposes, the NHC uses a representative sample of hypothetical storms to estimate the near worst-case scenario of flooding for each hurricane category.This is version 3 of the NHC National Storm Surge Risk Maps. The updates in this version include data mapped to 10m DEMs for the US Gulf and East Coast. The following new regions have been added: Southern California (hurricane wind category 1 and 2 storms), Guam, American Samoa, and the Yucatan Peninsula for parts of Mexico, Belize, and Honduras. For simplicity, the tiled map services are published by hurricane wind category and all available mapped regions for that category are provided in that web map.The following areas are mapped:US Gulf and East Coast (Category 5 south of NC/VA border only)Puerto Rico and US Virgin IslandsSouthern California (Category 1-2 only)Hawaii (Category 1-4 only)GuamAmerican SamoaHispaniolaYucatan Peninsula- parts of Mexico, Belize, Guatemala, and western HondurasSLOSH employs curvilinear polar, elliptical, and hyperbolic telescoping mesh grids to simulate the storm surge hazard. The spatial coverage for each SLOSH grid ranges from an area the size of a few counties to a few states. The resolution of individual grid cells within each basin ranges from tens to hundreds of meters to a kilometer or more. Sub-grid scale water features and topographic obstructions such as channels, rivers, and cuts and levees, barriers, and roads, respectively, are parameterized to improve the modeled water levels.The NHC provides two products based on hypothetical hurricanes: MEOWs and MOMs. MEOWs are created by computing the maximum storm surge resulting from up to 100,000 hypothetical storms simulated through each SLOSH grid of varying forward speed, radius of maximum wind, intensity (Categories 1-5), landfall location, tide level, and storm direction. A MEOW product is created for each combination of category, forward speed, storm direction, and tide level. SLOSH products exclude Category 5 storms north of the NC/VA border. SLOSH products only include hurricane wind Category 1-4 scenarios for Hawaii and hurricane wind category 1-2 scenarios for Southern California. For each storm combination, parallel storms make landfall in 5 to 10 mile increments along the coast within the SLOSH grid, and the maximum storm surge footprint from each simulation is composited, retaining the maximum height of storm surge in a given basin grid cell. These are called MEOWs and no single hurricane will produce the regional flooding depicted in the MEOWs. SLOSH model MOMs are an ensemble product of maximum storm surge heights. SLOSH MOMs are created for each storm category by retaining the maximum storm surge value in each grid cell for all the MEOWs, regardless of the forward speed, storm trajectory, or landfall location. SLOSH MOMs are available for mean tide and high tide scenarios and represent the near worst-case scenario of flooding under ideal storm conditions. A high tide initial water level was used for the storm surge hazard maps.This product uses the expertise of the NHC Storm Surge Unit to merge the operational SLOSH grids to build a seamless map of storm surge hazard scenarios using the MOM product. Each individual SLOSH grid for the Category 1-5 MOMs are merged into a single, seamless grid. The seamless grid is then resampled, interpolated, and processed with a DEM (Digital Elevation Model, i.e. topography) to compute the storm surge hazard above ground for each hurricane wind category. The SLOSH MOM storm surge hazard data used to create these maps are constrained by the extent of the SLOSH grids and users should be aware that risk due to storm surge flooding could extend beyond the areas depicted in these maps.Users of this hazard map should be aware that potential storm surge flooding is not depicted within some levee areas, such as the Hurricane & Storm Damage Risk Reduction System in Louisiana. These areas are highly complex and water levels resulting from overtopping are difficult to predict. Users are urged to consult local officials for flood risk inside these leveed areas. If applicable to the region displayed by the map, these leveed areas will be depicted with a black and white diagonal hatch pattern. Not all levee areas are included in this analysis - in particular, local features such as construction walls, levees, berms, pumping systems, or other mitigation systems found at the local level may not be included in this analysis. Additionally, some marshy or low lying areas are not mapped in this analysis.In locations that have a steep and narrow continental shelf, wave setup can be a substantial contributor to the total water level rise observed during a tropical cyclone. Wave setup is defined as the increase in mean water level due to momentum transfer to the water column by waves that are breaking or otherwise dissipating their energy. The following locations use SLOSH+Wave Setup simulations to create MEOW and MOM products that account for the increase in the mean water level due to wave setup: Puerto Rico, US Virgin Islands, Hawaii, Hispaniola, Guam, American Samoa, and Southern California. Through the USAID/WMO Coastal Inundation and Flooding Demonstration Project, these SLOSH storm surge risk products were created for the Island of Hispaniola.