Flash Flood Prediction Program

-	Thunderstorms have developed this afternoon as surface moisture increased behind a cold that moved through early this afternoon. High temperatures have decreased slightly behind the cold front, but enough daytime heating has returned to initiate moderate thunderstorms favoring areas north and east as these storms move through.
-	Best chance for thunderstorm activity will be from now through 9:00pm with thunderstorm chances decreasing significantly after sunset. Scattered, more widespread showers are expected later this evening with no threat of heavy rain.
-	Showers and thunderstorms this afternoon will move from WSW to ENE at around 20mph then upper level steering winds will turn to the N/NE overnight as upslope flow develops. Typical storms today will produce light to moderate rain, heavy rainfall is not anticipated.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and weak thunderstorms will produce a trace to 0.2" in 10-30 minutes. A moderate thunderstorm will be capable of producing 0.2-0.6" in 10-30 minutes. Rain showers overnight will result in rainfall rates of up to 0.2"/hr.

WORST CASE SCENARIO: A unexpected strong thunderstorm develops with the potential to produce 0.4-1.2" in 10-30 minutes.

A LOOK AHEAD: Unseasonably cool on Sunday with highs only in the 50's to lower 60's over the plains. There will be a chance for lingering rain showers in the morning all areas and isolated thunderstorms in the afternoon favoring the foothills. Heavy rainfall is not expected.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 900 PM SAT	Trace (70%) to 0.3" (40%) to 0.6" (20%)	LOW
Arapahoe	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Boulder	Current TO 900 PM SAT	Trace (70%) to 0.3" (40%) to 0.6" (20%)	LOW
Broomfield	Current TO 900 PM SAT	Trace (70%) to 0.3" (40%) to 0.6" (20%)	LOW
Denver	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Douglas	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Jefferson	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Foothills above 6500ft
Boulder	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Douglas	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW
Jefferson	Current TO 900 PM SAT	Trace (70%) to 0.3" (30%) to 0.6" (10%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.