NOAA’s National Weather Service Flood and Flash Flood Warning Program Michelle Schmidt Western Region Hydrology and Climate Services Division

Outline Mission of the NWS Hydrology ProgramMission of the NWS Hydrology Program Impacts of floods in the United StatesImpacts of floods in the United States Field Structure for the Hydrology ProgramField Structure for the Hydrology Program Watches and WarningsWatches and Warnings Floods versus Flash FloodsFloods versus Flash Floods Improving the hydrology programImproving the hydrology program

Provide river and flood forecasts and warnings for the protection of lives and property.Provide river and flood forecasts and warnings for the protection of lives and property. Provide basic hydrologic forecast information for the nation’s environmental and economic well being.Provide basic hydrologic forecast information for the nation’s environmental and economic well being. Mission of NWS Hydrologic Services Program

$0.03 $0.69 $0.06 $0.44 $0.87 $5.60 $4.97 Impacts of Natural Disasters United States of America Tornado Hail Cold Lightning Heat Flood Hurricane Winter Storm Average Annual Deaths ( ): 502 Average Annual Damages ( ): $13.1 Billion Flood Hurricane Flood Heat $0.47

National Weather Service Hydrology Program Flash Flood ProgramFlash Flood Program Flood ForecastingFlood Forecasting Snowmelt ForecastingSnowmelt Forecasting Water Supply ForecastingWater Supply Forecasting Dam Break SupportDam Break Support

Hydrology Program Field Office Support Services provided through collaborative efforts of National Centers, River Forecast Centers (RFCs), and Weather Forecast Offices (WFOs) Hydrometeorological Prediction Center (HPC) Camp Springs, MD Storm Prediction Center (SPC) Norman, OK

NWS Products Watches and Warnings Flood Watch Flood Watch Inform the public of conditions which may cause flooding - flooding is not certain or imminentInform the public of conditions which may cause flooding - flooding is not certain or imminent Possible flooding in the next 36 hoursPossible flooding in the next 36 hours Alert decision makers to pay closer attention and position resourcesAlert decision makers to pay closer attention and position resources

NWS Products Watches and Warnings Flash Flood and Flood Warnings Flash Flood and Flood Warnings Flooding is imminentFlooding is imminent Provide advance notification of flood events which require immediate action to protect lives and propertyProvide advance notification of flood events which require immediate action to protect lives and property Allow customers and partners to take immediate mitigation actions such as evacuation to higher groundAllow customers and partners to take immediate mitigation actions such as evacuation to higher ground

Floods versus Flash Floods River FloodRiver Flood River rises to flood stage over many hours or days (6 hours or more)River rises to flood stage over many hours or days (6 hours or more) Longer lasting eventsLonger lasting events Hydrologic eventHydrologic event Flash Flood Quick responding streams and rivers – 6 hours or less after the heavy rain started Meteorological event Different Events  Different program  Different tools

Floods River Flood Program

Spring snowmelt flooding Heavy rain flooding

Flood Warning Mission 1. National Center: Hydrometeorological Prediction Center Quantitative Precipitation Forecasts TemperatureForecasts

Flood Warning Mission 2. River Forecast Centers (RFCs) Calibrate, maintain and run hydrologic model – NWSRFSCalibrate, maintain and run hydrologic model – NWSRFS Produce hydrologic forecastsProduce hydrologic forecasts Provide the forecasts to the Weather Forecast Offices (WFOs)Provide the forecasts to the Weather Forecast Offices (WFOs)

River Forecast Center Tools

Flood Warning Mission 3.Weather Forecast Offices (WFOs) Customer outreachCustomer outreach Field work to keep information up to date (flood stage, impacts, etc..)Field work to keep information up to date (flood stage, impacts, etc..) Monitor situationMonitor situation Issue flood watches and warnings based on forecasts from the River Forecast CentersIssue flood watches and warnings based on forecasts from the River Forecast Centers

Operational Tools at the WFO WHFS – components Viewing Editor - Quality control Database Product maker

UTC FLOOD WARNING NATIONAL WEATHER SERVICE SALT LAKE CITY UT 115 PM MDT TUE MAY RIVER FLOOD WARNING FOR THE UPPER WEBER RIVER UNTIL FURTHER NOTICE.. THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A RIVER FLOOD WARNING FOR THE UPPER WEBER RIVER FROM THE OUTLET OF SMITH MOREHOUSE RESERVOIR TO ROCKPORT RESERVOIR. THIS WARNING IS IN EFFECT UNTIL FURTHER NOTICE. THE LATEST STAGE FOR THE WEBER RIVER NEAR OAKLEY IS 4.3 FEET AT 12 PM TUESDAY. MINOR FLOODING IS FORECASTED...WITH A MAXIMUM STAGE OF 4.5 FEET AT 6 AM WEDNESDAY...WHICH IS EQUAL TO THE FLOOD STAGE. THE RIVER IS FORECAST TO CONTINUALLY RISE THROUGH SUNDAY...MAY 29TH. FLOODING IS EXPECTED TO IMPACT STRUCTURES ADJACENT TO THE RIVER BELOW SMITH MOREHOUSE RESERVOIR TO ROCKPORT RESERVOIR. THESE WATERS ARE VERY COLD...FAST...AND DANGEROUS. PLEASE USE CAUTION WHEN RECREATING NEAR THESE WATERS. ALSO...PLEASE MONITOR ANY CHILDREN WHO MAY VENTURE TOO CLOSE TO THESE RIVERS AND STREAMS. STAY TUNED TO NOAA WEATHER RADIO...YOUR FAVORITE LOCAL MEDIA SOURCE...OR ON THE INTERNET AT WEATHER.GOV FOR THE LATEST HYDROLOGIC INFORMATION.

Advanced Hydrologic Prediction Services – AHPS Improving Hydrologic Services Improving disseminationImproving dissemination More graphicsMore graphics More standard formatsMore standard formats Better use of the InternetBetter use of the Internet User friendlyUser friendly

Flash Flood Program

Flash Floods Driven by heavy rain Respond too quickly to be modeled in RFC hydrologic model Meteorologic event

Flash Flood Warning Program 1. National Centers Storm Prediction Center - heavy rain meso-scale discussionStorm Prediction Center - heavy rain meso-scale discussion Hydrometeorologic Prediction Center - excessive rainfall product and quantitative precipitation productHydrometeorologic Prediction Center - excessive rainfall product and quantitative precipitation product

Flash Flood Warning Program 2. River Forecast Centers (RFCs) - Flash Flood Guidance - Flash Flood Guidance

Flash Flood Warning Program 3. Weather Forecast Offices ( ) 3. Weather Forecast Offices ( )ttp://weather.gov/ttp://weather.gov/ Pre-event partner/customer outreach and educationPre-event partner/customer outreach and education Hydrometeorological monitoring and threat assessmentHydrometeorological monitoring and threat assessment Issuance of Flash Flood Watches and WarningsIssuance of Flash Flood Watches and Warnings

Advanced Hydrologic Prediction Services - AHPS Improving Hydrologic Services Flash Flood Monitoring and Prediction – FFMPFlash Flood Monitoring and Prediction – FFMP Continuous monitoring of rainfall rates and accumulations compared to flash flood guidance for high resolution basinsContinuous monitoring of rainfall rates and accumulations compared to flash flood guidance for high resolution basins Automated alerts when dangerous flash flood situations may be developingAutomated alerts when dangerous flash flood situations may be developing Distributed to the Weather Forecast Offices in 2002Distributed to the Weather Forecast Offices in 2002

Flash Flood Monitoring and Prediction FFMP Data Integration

2130 – 2135 UTC Rainfall (in/hr) Grid size 1 o x 1km Flash Flood Monitoring and Prediction Mapping Radar Bins to a Basin Watershed Boundary

Flash Flood Monitoring and Prediction County Precipitation Accumulation Displays precipitation for the basin in the county that has highest accumulationDisplays precipitation for the basin in the county that has highest accumulation FFMP 1.0 Hour Basin Avg Precip

Flash Flood Monitoring and Prediction Basin Precipitation Accumulation Displays basin precipitation within the selected countyDisplays basin precipitation within the selected county FFMP 1.0 Hour Basin Avg Precip

Summary National Weather Service mission is to save lives and propertyNational Weather Service mission is to save lives and property National, regional and local offices work together to carry out this missionNational, regional and local offices work together to carry out this mission Weather Forecast Offices issue watches and warning to the publicWeather Forecast Offices issue watches and warning to the public Continuously improving our servicesContinuously improving our services

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