Time: 937 AM Thu August 25, 2022 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- MOSTLY SUNNY WITH A CHANCE FOR AFTERNOON SHOWERS/THUNDERSTORMS - Warm conditions continue as an upper-level disturbance over the Pacific Northwest transports a plume of moisture into the region, supporting increased thunderstorm activity today with highs reaching the upper 80’s to low 90’s this afternoon. - Initial storm development will occur along the higher terrain towards the west between noon and 2pm. These storms will likely move into the District between 1-3pm with the best chance for storm activity through 9pm. Current dew points in the mid 40's to around 50 should mix out during the morning into the low to mid 40's effectively limiting the amount of available, however, models suggest an uptick in surface moisture this afternoon resulting in a LOW chance for Message 1 issuance this afternoon. - Storm motions will generally be from the NNW to ESE between 10-15mph helping limit point rainfall amounts, however, additional storm development along outflow boundaries has the potential to produce slower moving, if not stationary storms at times. Storms today will also likely be very pulse like with generally a trace to 0.2" of rainfall, however a LOW threat today will see a storm produce a quick 0.5" in 10-15 minutes. Isolated higher amounts cannot be completely ruled out at this time if stronger storms are able to develop, although the threat will remain minimal today. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a trace to 0.2" of rainfall in 10-30 minutes. A moderate to strong rain showers/isolated thunderstorm could produce 0.2-0.5" in 10-30 minutes. WORST CASE SCENARIO: A slow-moving or anchored rain shower/isolated thunderstorm will have the potential to produce 0.5-1.5" in 45-75 minutes. A LOOK AHEAD: With the weekend on the horizon, the District will once again be in the cross hairs for an active weather pattern with storms chances likely Friday, Saturday and Sunday. Tomorrow will likely be the most active day with a good chance for afternoon and evening storm activity with at least a moderate chance for heavy rainfall at this time. Storm chances taper off slightly both Saturday and Sunday, although a LOW threat will likely remain for moderate to heavy afternoon rain showers/thunderstorms. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Arapahoe 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Boulder 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Broomfield 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Denver 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Douglas 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Jefferson 200 PM TO 900 PM Trace (60%) to 0.2" (30%) to 0.5" (10%) LOW Foothills above 6500ft       Boulder 200 PM TO 900 PM Trace (70%) to 0.2" (40%) to 0.5" (15%) LOW Douglas 200 PM TO 900 PM Trace (70%) to 0.2" (40%) to 0.5" (15%) LOW Jefferson 200 PM TO 900 PM Trace (70%) to 0.2" (40%) to 0.5" (15%) 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]