Flash Flood Prediction Program

Time: 856 AM Tue May 3, 2022 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- DRY TODAY WITH HIGH-BASED AFTERNOON RAIN/ISO THUNDERSTORMS, WITH EVENING AND OVERNIGHT RAIN SHOWERS LIKELY - An isolated foggy start to the day today with partly cloudy skies as high temperatures reach the low to mid 60's this afternoon. A disturbance will move into the region late this afternoon bringing a chance for scattered high-based rain showers/isolated thunderstorms, with a better chance for rain showers this evening and through the overnight and into Wednesday morning. - Minimal precipitation is expected during the afternoon as high-based rain showers will mainly produce gusty winds with most precipitation struggling to reach the surface. An uptick in upper-level moisture this evening will bring a better chance for rain showers late with scattered off and on rain showers possible through the overnight and into Wednesday morning. With decent upper-level support through the overnight, can't completely rule out a few storms could strengthen enough to produce some lightning and bring some moderate rainfall to brief isolated heavy rainfall, although chances remain very low at this time. - Best chance for high-based rain/isolated thunderstorms will be from 3-8pm with off and on rain showers likely from 8pm through the overnight and into daybreak Wednesday. A better chance for meaningful rainfall after 8pm, however storm intensity will also decrease at this time as thunderstorm activity diminishes significantly after 8pm. Overnight lows will drop into the mid to upper 30's, resulting in a slight chance for mix/snow for higher elevations through the overnight and into daybreak Wednesday. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a trace to 0.2" of rainfall in 10-30 minutes. Weak to moderate thunderstorms will have the potential to produce rainfall rates of 0.2-0.4" in 10-30 minutes. WORST CASE SCENARIO: A strong thunderstorm is able to develop with the potential for moderate to brief heavy rainfall of 0.4-0.8" in 30-60 minutes. A LOOK AHEAD: This unsettled weather pattern remains over the region Wednesday bringing a continued chance for off and on rain showers throughout the day. Cooler daytime temperatures will help limit rainfall intensity throughout the day Wednesday with another chance for overnight precipitation and into early Thursday morning. A few lingering rain showers will be possible Thursday morning with conditions drying out throughout the day as high temperatures reach the low to mid 60's. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Arapahoe 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Boulder 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Broomfield 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Denver 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Douglas 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Jefferson 400 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (20%) NONE Foothills above 6500ft       Boulder 300 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (10%) NONE Douglas 300 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (10%) NONE Jefferson 300 PM TO 900 AM WED Trace (90%) to 0.2" (50%) to 0.4" (10%) NONE MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]