Flash Flood Prediction Program

Time: 635 AM Thu May 11, 2023 Forecaster: Justin Brooks ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2'S HAVE BEEN ISSUED FOR THE ENTIRE DISTRICT Message 2's have been issued for the entire District effective from 6am this morning valid until 6am Thursday, May 12, 2023. An active day expected weather wise as widespread moderate to heavy rain showers impact the District today, this evening, and through the overnight tonight. Currently temperatures are relatively cool, resulting in just typical rain showers currently. As the day progresses, and there’s a bit more daytime heating, there will be a better chance for impactful rain showers across the District this afternoon, evening and overnight. This has resulted in the issuance of a Flood Watch for the entirety of the District effective now, through 6am Thursday, May, 12th. Elevated moisture both at the surface and aloft today will result in efficient rain producing showers and thunderstorms. The storm motions currently SE to NW and will shift through the day becoming N to S later today and into this evening. Storm motions will be generally between 5-15mph, however training of heavy rain showers bringing over 1" per hour rainfall rates, or an anchored/slow moving shower/thunderstorm will bring the biggest threat for heavy rainfall today, this evening and through the overnight. Off and on rain showers are likely to continue into Friday, although the threat of heavy rainfall is minimal at this time. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers will produce 0.2-0.5" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce rainfall rates of 0.5-1.5" in 10-30 minutes. WORST CASE SCENARIO: A strong/slower moving or stationary thunderstorm, or training of rain showers/thunderstorms may result in heavy rainfall rates of up to 3.0" in 45-60 minutes. COUNTY MESSAGE VALID TIMES PRIME TIME Lakewood 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Arvada 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Wheat Ridge 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Broomfield County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Douglas County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Adams County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Denver County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY DIA 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Arapahoe County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY the City of Aurora 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Jefferson County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY Boulder County 2 Current TO 600 AM FRIDAY Current TO 600 AM FRIDAY County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Arapahoe Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Boulder Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Broomfield Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Denver Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Douglas Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Jefferson Current TO 600 AM FRI 0.2" (100%) to 0.5" (75%) to 1.5" (25%) ISSUED Foothills above 6500ft       Boulder Current TO 600 AM FRI 0.2" (80%) to 0.5" (50%) to 1.5" (15%) ISSUED Douglas Current TO 600 AM FRI 0.2" (80%) to 0.5" (50%) to 1.5" (15%) ISSUED Jefferson Current TO 600 AM FRI 0.2" (80%) to 0.5" (50%) to 1.5" (15%) ISSUED MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]