Time: 853 AM Mon September 2, 2024 Forecaster: Tim Tonge ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- Breezy and almost entirely dry for Labor Day As mentioned yesterday, the slow degradation of the ridge over Colorado has begun, and will take place for the next 36 hours or so as a trough approaches from the Pacific Northwest. The effects from the high pressure circulation will remain in place today, suppressing almost all convection east of the Continental Divide. Some moisture has begun to pool west of the Divide, and will increase as the day goes on, so the mountains will likely see some isolated showers throughout the day. One or two showers have a small chance of pushing over the Divide under westerly upper-level flow that develops late afternoon, but will likely sputter out as they move into the dry air present in the foothills and urban corridor, releasing minimal rain and gusty outflow winds. Otherwise, Labor Day will arrive in the District with mostly clear skies, afternoon highs around 90, and breezy winds that will pick up and become quite gusty as the afternoon becomes the evening. STORM RAINFALL POTENTIAL AND DURATION: A stray shower or two in the foothills will produce Trace-0.10" in 10-30 minutes. A LOOK AHEAD: A similar day tomorrow with slightly increased surface moisture but minimal forcing that will keep storm chances minimal and message issuance potential at a NONE. Wednesday, the trough will arrive from the west, delivering a cold front that will drop temperatures and support scattered/widespread showers and thunderstorms Wednesday afternoon and evening. Some residual moisture will bring another isolated chance of storms Thursday before conditions dry out again by the weekend. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Foothills above 6500ft       Boulder 300 PM TO 700 PM Trace (15%) to 0.05" (10%) to 0.1" (5%) NONE Douglas 300 PM TO 700 PM Trace (15%) to 0.05" (10%) to 0.1" (5%) NONE Jefferson 300 PM TO 700 PM Trace (15%) to 0.05" (10%) to 0.1" (5%) 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]