Flash Flood Prediction Program

Time: 937 AM Wed May 3, 2023 Forecaster: Laura Smith ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- WARM CONDITIONS ACROSS THE DISTRICT TODAY WITH ISOLATED SHOWERS ACROSS THE FOOTHILLS An Omega blocking pattern is in place across the continental US, suppressing thunderstorm activity along the Plains. As a result, this morning will be dry followed by afternoon temperatures in the upper 70s to low 80s. Chances for showers and thunderstorms will remain minimal today with dewpoints in the upper 20s to low 30s across the District. Areas along the foothills and Palmer Divide have slightly better chances for a brief isolated thunderstorm or two due to orographic support. The best chances for precipitation activity will be between 4PM and 8PM. With upper-level flow out of the west-southwest, showers are expected to favor mostly westerly trajectories before dissipating upon reaching the plains. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a TR-0.10” in 10-30 minutes. A moderate rain shower/isolated thunderstorm could produce 0.10-0.20” in 10-30 minutes. WORST CASE SCENARIO: An anchored rain shower/isolated thunderstorm, or training of rain showers, has the potential to produce 0.20-0.40” in 45-60 minutes. A LOOK AHEAD: High-pressure ridging continues over the Intermountain West ahead of an upper-level disturbance slowly advancing across the Great Basin. The Omega block will begin to recede tonight, allowing moisture and upper-level support to improve across Colorado. Afternoon temperatures tomorrow will reach the mid 70s with dew points climbing into the upper 30s to low 40s, resulting in a more active weather pattern. These conditions will support widespread early afternoon to early evening showers and thunderstorms across the District. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Arapahoe 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Boulder 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Broomfield 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Denver 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Douglas 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Jefferson 400 PM TO 800 PM Trace (25%) to 0.1" (15%) to 0.2" (5%) NONE Foothills above 6500ft       Boulder 400 PM TO 800 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Douglas 400 PM TO 800 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Jefferson 400 PM TO 800 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) 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]