Flash Flood Prediction Program

-	A cold front moved in overnight resulting in increased surface moisture with dew points expected to hold in the low to mid 50's bringing a good chance for heavy rainfall this afternoon and early evening. Temperatures today will reach the low to mid 80's across the plains with low to mid 70's along the foothills.
-	Rain showers and thunderstorms will start to develop around midday along the Palmer Divide and the foothills. Storms will begin to move off the higher terrain between 12-2pm with the initial round of storms having a good chance of becoming severe along the I-25 corridor and eastward out on the plains. Additional storm development behind the initial round will be less severe, although will still have the potential for heavy rainfall as an abundance of moisture will remain in place throughout the day.
-	Storms today will move from W/SW to E/NE at 5-10mph and will contain isolated heavy rainfall, large hail, gusty winds, and frequent lightning. By sunset, storm activity should diminish over the District as skies clear through the overnight. Lows tomorrow morning will drop into the upper 50's to low 60's, with another chance tomorrow afternoon for rain showers/isolated thunderstorms.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/thunderstorms will produce a 0.1-0.3" in 10-30 minutes. A moderate to strong thunderstorm will produce 0.3-1.0" in 10-30 minutes. Supplemental QPF is available at https://qpf.udfcd.org

WORST CASE SCENARIO: A slow moving/stationary strong thunderstorm formed along an outflow boundary could produce up to 2.0" in 45-60 minutes.

A LOOK AHEAD: Warmer tomorrow and Thursday with a decreased chance for afternoon and evening rain showers/isolated thunderstorms. A monsoon type pattern begins to set up Friday resulting in a increased chance for rain showers/thunderstorms, with heavy rain possible through the weekend.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	100 PM TO 800 PM	0.1" (70%) to 0.3" (50%) to 1.0" (20%)	HIGH
Arapahoe	100 PM TO 800 PM	0.1" (70%) to 0.3" (50%) to 1.0" (30%)	HIGH
Boulder	100 PM TO 800 PM	0.1" (60%) to 0.3" (40%) to 1.0" (20%)	HIGH
Broomfield	100 PM TO 800 PM	0.1" (60%) to 0.3" (40%) to 1.0" (20%)	HIGH
Denver	100 PM TO 800 PM	0.1" (60%) to 0.3" (40%) to 1.0" (20%)	HIGH
Douglas	100 PM TO 800 PM	0.1" (80%) to 0.3" (50%) to 1.0" (30%)	HIGH
Jefferson	100 PM TO 800 PM	0.1" (60%) to 0.3" (40%) to 1.0" (20%)	HIGH
Foothills above 6500ft
Boulder	100 PM TO 800 PM	0.1" (60%) to 0.3" (30%) to 1.0" (15%)	MOD
Douglas	100 PM TO 800 PM	0.1" (60%) to 0.3" (40%) to 1.0" (20%)	HIGH
Jefferson	100 PM TO 800 PM	0.1" (60%) to 0.3" (30%) to 1.0" (15%)	MOD

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.