Time: 955 AM Wed July 17, 2024 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Scattered to widespread Afternoon to evening showers and thunderstorms Subtropical moisture continues improving today following last night’s cold front, while afternoon high temperatures are expected to be much cooler, reaching the mid 80s across the Front Range Urban Corridor. Dewpoints will be in the low 50s with precipitable water (PWAT) values around 0.85”. These conditions will support scattered to widespread thunderstorms this afternoon and evening. Like yesterday, convection initiation will begin around noon across complex terrain, with storms moving east onto the plains between 15-20 mph. Conditions for heavy rain are better across the foothills and east of the District. However, stronger storms across the eastern Plains of Colorado have the potential to produce outflow boundaries that move west into the District, initiating slow-moving storms with the potential to produce meaningful rainfall. Thunderstorm activity is expected to dissipate by the late evening, with skies gradually clearing overnight. STORM RAINFALL POTENTIAL AND DURATION: Thunderstorms today have the potential to produce 0.25”-1.00” in 10-30 minutes. WORST CASE SCENARIO: A slow-moving, strong thunderstorm may be capable of producing up to 1.50” or more in 30 minutes or less. A LOOK AHEAD: Dry(er) air and hot afternoon temperatures return Thursday, with highs climbing into the 90s across the Plains with chances for showers and thunderstorms through the evening. Storms are expected to produce light to briefly moderate rainfall as drying continues through the day. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Arapahoe 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Boulder 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Broomfield 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Denver 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Douglas 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Jefferson 100 PM TO 800 PM 0.25" (50%) to 0.5" (30%) to 1" (10%) MOD Foothills above 6500ft       Boulder 100 PM TO 800 PM 0.25" (60%) to 0.5" (40%) to 1" (20%) HIGH Douglas 100 PM TO 800 PM 0.25" (60%) to 0.5" (40%) to 1" (20%) HIGH Jefferson 100 PM TO 800 PM 0.25" (60%) to 0.5" (40%) to 1" (20%) HIGH MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]