Time: 1212 PM Sun June 11, 2023 Forecaster: Justin Brooks ------------------------- MESSAGE 2 Flash Flood Prediction Program ------------------------- FLASH FLOOD WATCH The National Weather Service has issued a FLASH FLOOD WATCH for: the following counties: ARAPAHOE, DENVER, ADAMS, DOUGLAS, BROOMFIELD, JEFFERSON, BOULDER (CITY OF BOULDER AFFECTED, FOUR MILE BURN AREA AFFECTED) including: ARVADA, THE CITY OF AURORA, DIA, WHEAT RIDGE, LAKEWOOD ------------------------------------------------------------------------------ from: 100 PM to 300 AM . THE NATIONAL WEATHER SERVICE IN BOULDER HAS ISSUED A FLOOD WATCH FOR THE ENTIRE DISTRICT EFFECTIVE FROM 3:00 PM TODAY, JUNE 11TH 2023, UNTIL 3:00 AM MONDAY, JUNE 12TH, 2023. Prime time for flooding: 200 PM to 200 AM . ------------------------------------------------------------------------------ Forecast rainfall: Typical thunderstorms have the potential to produce moderate to heavy rainfall of 0.40” to 0.75” total, in 10 to 30 minutes. Moderate to strong thunderstorms will have the potential to produce heavy rainfall rates of 0.75-1.50" total, in 10-30 minutes. A nearly stationary thunderstorm or large thunderstorm complex may produce up to 2.5" of heavy rain total, in 45-60 minutes. ------------------------------------------------------------------------------ The most likely areas to be impacted by flooding are: X Mountain streams & floodplains; road crossings; canyon roads & highways; recreational trails; adjacent open space areas/campgrounds/parks; fishing access points & stream reaches; buildings near streams; utilities X Urban streams/gulches; road crossings; recreational trails; adjacent open space areas/campgrounds/parks; floodplain properties; utilities X Urban streets, intersections, low lying areas, known trouble spots X Mountain locations subject to mud/rock/debris slide ------------------------------------------------------------------------------ Additional information: Excessive runoff roadways is likely to develop over the District today, this evening and through the overnight tonight with Flash flooding of watercourses possible today should a stronger thunderstorm be observed. A Flash Flood Watch means that flash flooding is possible within the watch area. This message is not intended for public dissemination. Please pass this information along to affected emergency response organizations (police, fire, public works, etc.) within your area. Also, please take appropriate actions to prepare for possible flooding. Further information will be provided to you as it becomes available. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]