Flash Flood Prediction Program

Time: 913 AM Tue May 17, 2022 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HOT TODAY WITH ANOTHER CHANCE FOR HIGH-BASED AFTERNOON/EVE RAIN/ISOLATED THUNDERSTORMS - Another well above average temperature day with highs well into the 80's on the plains with mid to upper 70's along the foothills this afternoon. Best chance for rain shower/isolated thunderstorm activity today will be from noon until 8pm with a few lingering rain showers possible through the evening and into the overnight with minimal precipitation expected. - With high temperatures in the 80's with dew points dropping to the low 30's this afternoon will result in a couple of rounds of high-based rain showers with minimal precipitation expected as most rainfall will struggle to reach the surface. However, if moisture does increase at the surface this afternoon, a few stronger storms have the potential to develop this evening bringing isolated moderate to heavy rainfall. A few isolated thunderstorms cannot be completely ruled out also, favoring the foothills and areas northward towards the Colorado/WY border through the afternoon and evening at this time. - Rainfall chances for the District taper off after midnight as overnight lows drop into low to mid 50's on the plains, with mid to upper 40's along the foothills. Mild and dry conditions are expected through daybreak Wednesday. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a trace to 0.1" of rainfall in 10-30 minutes. Weak to moderate thunderstorms will have the potential to produce rainfall rates of 0.1-0.4" in 10-30 minutes. WORST CASE SCENARIO: An increase in surface moisture has the potential to produce moderate to strong thunderstorm, or training of thunderstorms with the potential for moderate to brief heavy rainfall of 0.4-1.2" in 30-60 minutes. A LOOK AHEAD: An uptick in moisture Wednesday will result in a better chance for widespread afternoon/eve rain/thunderstorms with a low chance at this time for a heavy rainfall threat. A break in the pattern Thursday with mostly dry conditions throughout the day, with a chance for late evening rain showers with off and on rain showers through the day Friday with a chance for rain/mix and possibly some snow Friday evening and into Saturday morning. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Arapahoe 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Boulder 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Broomfield 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Denver 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Douglas 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Jefferson 1200 PM TO 1159 PM Trace (30%) to 0.1" (15%) to 0.4" (5%) NONE Foothills above 6500ft       Boulder 1200 PM TO 1159 PM Trace (40%) to 0.1" (20%) to 0.4" (10%) NONE Douglas 1200 PM TO 1159 PM Trace (40%) to 0.1" (20%) to 0.4" (10%) NONE Jefferson 1200 PM TO 1159 PM Trace (40%) to 0.1" (20%) 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]