Flash Flood Prediction Program

Time: 922 AM Fri May 5, 2023 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- GENERALLY DRY AND BREEZY WITH A SLIGHT CHANCE FOR A VERY ISOLATED SHOWER/WEAK THUNDERSTORM Conditions will trend on the dry side over the majority of the District today with above normal temperatures and breezy winds. Afternoon highs will reach the mid to upper 70’s over the plains with 60’s in the Front Range foothills. Normal high for Denver today is 66°F. Winds will be from the SW to W at 10-20mph, gusting to 30-35mph. Skies will begin the day sunny and then become partly cloudy this afternoon with any shower or thunderstorm activity likely limited to the higher mountains and foothills and over far NE Colorado leaving the District sandwiched in-between on the drier side. Isolated afternoon thunderstorms will be possible over the foothills between 1-8pm, favoring Boulder County over Douglas or Jefferson Counties. Should a shower or weak thunderstorm survive off the foothills the impacts will be minimal with storms producing more wind than rain. Overnight, conditions will be dry and winds will decrease with temperatures reaching the upper 30’s and lower 40’s for overnight lows along the I-25 corridor into Saturday morning. STORM RAINFALL POTENTIAL AND DURATION: Isolated rain showers and possibly a weak thunderstorm will produce a trace to 0.1” of rain over the lower elevations. WORST CASE SCENARIO: A foothill thunderstorm will have the potential to produce a trace to 0.2” in 10-30 minutes, favoring Boulder County. A LOOK AHEAD: Saturday will continue the dry trend for most with any chances for storms limited to the foothills. Temperatures will back off a handful of degrees with highs in the low to mid 70’s. Winds will continue breezy from the W/SW at 10-20mph, gusting to 25-30mph. A slight uptick in thunderstorm activity is expected Sunday with isolated afternoon and evening thunderstorms over the plains producing minimal moisture. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Arapahoe 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Boulder 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Broomfield 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Denver 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Douglas 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Jefferson 200 PM TO 800 PM Trace (15%) to 0.1" (5%) NONE Foothills above 6500ft       Boulder 100 PM TO 800 PM Trace (50%) to 0.1" (25%) to 0.2" (10%) NONE Douglas 100 PM TO 800 PM Trace (30%) to 0.1" (15%) to 0.2" (5%) NONE Jefferson 100 PM TO 800 PM Trace (25%) to 0.1" (10%) to 0.2" (5%) 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]