Flash Flood Prediction Program

Time: 837 AM Wed May 26, 2021 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- GENERALLY DRY WITH ISOLATED HIGH-BASED AFTERNOON THUNDERSTORMS/CHERRY CREEK FLUSHING OPERATION TODAY - An upper level disturbance will move through the District today but with little moisture to work with along and W of the I-25 corridor any storm development will be high-based with minimal rainfall. Stronger thunderstorms are expected to remain well E of the District this afternoon. - Highs will reach the 70's to around 80 over the plains under a veil of partly to mostly cloudy skies. The chance for high-based showers and weak thunderstorms will be between the hours of 3-7pm. Gusty winds and sprinkles are the most likely outcome from storms today with most areas remaining on the drier side. Far E areas of the District will have slightly better chances measurable precipitation. - The US Army Corps of Engineers will be performing the annual Cherry Creek Dam sediment flush today and will result in a rise along Cherry Creek through Denver which may inundate bike paths at times. A Message 1 Cherry Creek Trail Flood Advisory will be issued for the exercise and will be valid from 9am to 7pm today. STORM RAINFALL POTENTIAL AND DURATION: Typical high based showers and weak thunderstorms will produce a trace to 0.1" of rain. A stronger thunderstorm far eastern areas of the District will have the potential to produce 0.1-0.3" in 10-30 minutes. WORST CASE SCENARIO: Moisture levels remain elevated and strong to severe storms are able to develop further W than expected and result in 0.3-0.8" of rain in 10-30 minutes. A LOOK AHEAD: A cold front will move through tonight with highs on Thursday in the low to mid 70's over the plains. There will be a little better chance for isolated afternoon thunderstorms, mainly over the foothills and Palmer Divide. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 300 PM TO 700 PM Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE Arapahoe 300 PM TO 700 PM Trace (40%) to 0.1" (20%) to 0.3" (10%) NONE Boulder 300 PM TO 700 PM Trace (30%) to 0.1" (15%) to 0.2" (5%) NONE Broomfield 300 PM TO 700 PM Trace (20%) to 0.1" (10%) to 0.2" (5%) NONE Denver 300 PM TO 700 PM Trace (30%) to 0.1" (15%) to 0.3" (5%) NONE Douglas 300 PM TO 700 PM Trace (30%) to 0.1" (15%) to 0.2" (5%) NONE Jefferson 300 PM TO 700 PM Trace (30%) to 0.1" (15%) to 0.2" (5%) NONE Foothills above 6500ft       Boulder 200 PM TO 700 PM Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Douglas 200 PM TO 700 PM Trace (40%) to 0.1" (20%) to 0.2" (10%) NONE Jefferson 200 PM TO 700 PM Trace (40%) to 0.1" (20%) to 0.2" (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]