Time: 906 AM Wed July 6, 2022 Forecaster: Brad Simmons ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- HEAVY RAINFALL PRODUCING THUNDERSTORMS LIKELY THIS AFTERNOON AND EVENING - A substantial increase in moisture will result in the potential for heavy rainfall producing thunderstorms today which may lead to excessive runoff and possibly flash flooding within the District. Surface dew points are unusually high in the 60's this morning and are only expected to decrease into the mid and upper 50's this afternoon with precipitable water values well over 1.0". - Daytime heating in tandem with high moisture values will begin to produce showers and thunderstorms ahead of noon over the foothills. The strength of the storms over the plains will hinge upon daytime heating and more sun this morning will likely result in stronger storms this afternoon. The storms that develop will be slow moving from SW to NE at 10-15mph but stronger storms may anchor briefly or move erratically along surface boundaries. - Weak to moderate thunderstorms will be capable of producing brief heavy rainfall today with strong thunderstorms very capable of producing extended periods of heavy rainfall as well as gusty winds and hail. Prime time for thunderstorm activity is from 1-9pm. More numerous showers and thunderstorms will favor the foothills and Palmer Divide but the stronger storms will most likely favor the plains. STORM RAINFALL POTENTIAL AND DURATION: Rain showers will produce a trace to 0.2" in 10-30 minutes. Weak thunderstorms will produce rainfall rates of 0.2-0.6" in 10-30 minutes. Moderate to strong thunderstorms will have the potential to produce 0.6-1.8" in 10-30 minutes. WORST CASE SCENARIO: A large thunderstorm complex or a slow moving large thunderstorm may result in up to 3.0" of rain in 45-60 minutes. A LOOK AHEAD: Moisture will begin to decrease tomorrow resulting in the heavy rainfall threat lowering. There will still be ample moisture to fuel storms with isolated to widely scattered coverage in the afternoon/early evening. Temperatures will be near seasonal levels in the upper 80's to around 90 for highs. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Arapahoe 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Boulder 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Broomfield 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Denver 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Douglas 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Jefferson 100 PM TO 900 PM 0.2" (80%) to 0.8" (40%) to 1.6" (20%) HIGH Foothills above 6500ft       Boulder 1200 PM TO 900 PM 0.2" (90%) to 0.8" (50%) to 1.6" (15%) HIGH Douglas 1200 PM TO 900 PM 0.2" (90%) to 0.8" (50%) to 1.6" (15%) HIGH Jefferson 1200 PM TO 900 PM 0.2" (90%) to 0.8" (50%) to 1.6" (15%) 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]