Flash Flood Prediction Program

Time: 850 AM Mon September 16, 2024 Forecaster: Aaron O ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- More Very Isolated Showers this Afternoon with Mostly Sunny Skies Slightly warmer temperatures today, with highs in the low to mid 80s. Dew points will drop this afternoon to the low to mid 30s, limiting any significant point rainfall amounts. Precipitable water values are higher than yesterday, with 0.65” to 0.80”, but due to the low dew points and drying winds from the mountains point rainfall amounts will be significantly limited. Storm motion today will be SW to NE at 20-25 mph, which will also limit rainfall amounts. Rainfall amounts today should remain well below Message level amounts for The District. Storms should weaken around sunset and fully dissipate an hour or two after sunset, with skies clearing overnight. STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce rainfall rates of up to 0.10” total in 15-30 minutes. WORST CASE SCENARIO: A moderate to strong thunderstorm has the potential to produce up to 0.30” total rainfall 15-30 minutes. A LOOK AHEAD: Tomorrow will have a strong cold front move through The District in the afternoon. PWAT values of 0.70” to 0.80” and dew points in the low to mid 40s could have the potential to create Message level rainfall. Storm speeds should be quite high, 15-30 mph, which will limit point rainfall amounts, but storms still could possibly meet Message level criteria. A storm or two could possibly reach severe criteria of 60 mph gusts and hail up to 1 inch in diameter. The cold front should reach The District by the early afternoon. After the cold front leaves The District should dry out and continue to stay dry for the rest of the work week. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Arapahoe 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Boulder 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Broomfield 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Denver 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Douglas 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Jefferson 100 PM TO 900 PM Trace (30%) to 0.1" (20%) to 0.2" (10%) NONE Foothills above 6500ft       Boulder 100 PM TO 900 PM Trace (40%) to 0.1" (30%) to 0.2" (20%) NONE Douglas 100 PM TO 900 PM Trace (40%) to 0.1" (30%) to 0.2" (20%) NONE Jefferson 100 PM TO 900 PM Trace (40%) to 0.1" (30%) to 0.2" (20%) 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]