Flash Flood Prediction Program

Time: 841 AM Fri July 16, 2021 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- A BIT WARMER WITH ANOTHER CHANCE FOR SCATTERED RAIN SHOWERS/ISOLATED THUNDERSTORMS THIS AFTERNOON AND EARLY EVE - Mostly sunny skies once again this morning will help temperatures increase into the upper 80's to low 90's across the plains this afternoon with low to mid 80's along the foothills. Similar conditions as yesterday with a chance for afternoon rain showers and isolated thunderstorms. Currently dew points are in the upper 40's to around 50 and should continue to mix out through the morning, however, if dew points stay elevated into the afternoon there will be a better chance for rain showers and thunderstorms along the I-25 corridor this afternoon with the potential for isolated heavy rainfall favoring areas east of I-25 at this time. - The most likely outcome today will be a weak round of rain showers/isolated thunderstorms this afternoon between 2-4pm with storms increasing in intensity as they move out onto the eastern plains and away from the District. An outflow boundary that moves westerly from strong storms out on the eastern plains will have the potential to trigger additional storms within the District in the later afternoon and early evening which could have the potential for brief moderate to heavy rainfall. Any storm development should quickly decrease around sunset with mild and dry conditions into the rest of the evening. - Skies will gradually clear completely through the rest of the evening with overnight lows dropping into the low to mid 60's on the plains with mid to upper 50's along the foothills. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will produce a trace-0.2" of rainfall in 10-30 minutes. A moderate to strong thunderstorms will produce 0.2-0.4" of rainfall in 10-30 minutes. WORST CASE SCENARIO: A moderate to strong stationary thunderstorm formed along an outflow boundary has the potential to produce 1.2" in 45-60 minutes. A LOOK AHEAD: Not much will change with the overall pattern through the weekend with high temperatures remaining in the upper 80's to low 90's Saturday with a slightly better chance for afternoon rain showers/isolated thunderstorms. Similar conditions Sunday with high temps reaching the upper 80's to low 90's once again with another chance for afternoon rain showers/isolated thunderstorms. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (10%) LOW Arapahoe 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (10%) LOW Boulder 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Broomfield 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Denver 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (10%) LOW Douglas 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Jefferson 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Foothills above 6500ft       Boulder 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Douglas 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) LOW Jefferson 200 PM TO 900 PM 0.2" (40%) to 0.4" (20%) to 1.2" (5%) 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]