Flash Flood Prediction Program

Time: 1011 AM Mon August 22, 2022 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- WARM WITH A CHANCE FOR AFTERNOON RAIN SHOWERS/ISOLATED THUNDERSTORMS - Northwesterly upper-level flow aloft today will create warm conditions as high temperatures reach the low to mid 80's, dew points in the low 50's, by this afternoon. An upper level disturbance moves through the region today supporting a chance for afternoon rain showers/isolated thunderstorms. - Storm chances today will be low today as PW values across the District will reach 0.75-0.90 inches. However, a chance remains for a few rain showers/isolated thunderstorms this afternoon with the best chance between 1PM-7PM. Thunderstorm activity will favor the foothills, areas near the Palmer Divide, and east of the District today. Storm motions will be slow today, between 5-10mph from the NW to SE. - Overnight, skies will gradually clear with mild conditions expected. Lows will drop into the upper 50's to low 60's be daybreak Saturday. STORM RAINFALL POTENTIAL AND DURATION: Rain showers today will produce a trace to 0.2"-0.6" of rainfall in 10 to 30 minutes. WORST CASE SCENARIO: A slow-moving or anchored rain shower/thunderstorm will have the potential to produce 0.6"-1.2" in 10 to 30 minutes. A LOOK AHEAD: High pressure ridging remains the dominate pattern over the intermountain west, creating warm conditions across the District throughout the week. Tomorrow, high temperatures reach the mid to upper 80s with a slight chance for isolated afternoon showers and thunderstorms. Wednesday will be similar with highs in the mid to upper 80s and a slight chance for isolated thunderstorm activity. By the end of the week, an upper-level disturbance over the Pacific Northwest will transport a plume of moisture into the region, supporting increased thunderstorm activity. On Thursday and Friday, scattered showers and thunderstorms are likely as high temperatures remain in the mid 80s. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Arapahoe 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Boulder 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Broomfield 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Denver 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Douglas 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Jefferson 100 PM TO 700 PM Trace (30%) to 0.2" (20%) to 0.6" (10%) LOW Foothills above 6500ft       Boulder 1200 PM TO 800 PM Trace (50%) to 0.2" (25%) to 0.6" (10%) LOW Douglas 1200 PM TO 800 PM Trace (50%) to 0.2" (25%) to 0.6" (10%) LOW Jefferson 1200 PM TO 800 PM Trace (50%) to 0.2" (25%) to 0.6" (10%) LOW MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]