Flash Flood Prediction Program

-	Message 1's have been issued for the I-25 corridor eastward including Adams, Arapahoe, Denver and Douglas Counties until 4pm.
-	Dry air is approaching from the west but a line of thunderstorms is beginning to develop ahead of it over the plains and portions of the Palmer Divide. Surface moisture remains abundant over the plains currently and as temperatures continue to warm strong thunderstorms may develop in the deeper moisture along and E of I-25. Fast storm motions from S to N will limit point rainfall amounts from a single storm keeping the majority of the heavy rainfall brief but training of thunderstorm cells may result in a prolonged period of heavy rain that could lead to excessive runoff.
-	Strong thunderstorms may also become severe with large hail and gusty winds being the primary threats. As the dry air from the west moves into the District by mid afternoon thunderstorm chances will come to an end. Best chances for thunderstorm activity is until 4pm.

STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers/isolated thunderstorms will have the potential to produce a TR-0.3" in 10-30 minutes. A strong thunderstorm will have the potential to produce 0.3-0.8" in 10-30 minutes.

WORST CASE SCENARIO: Training of thunderstorm cells may result in up to 1.5" of rain in 45-60 minutes.

County	Message	Valid Times	Prime Time
the City of Aurora	1	Current TO 400 PM	Current TO 300 PM
Arapahoe County	1	Current TO 400 PM	Current TO 300 PM
DIA	1	Current TO 400 PM	Current TO 300 PM
Denver County	1	Current TO 400 PM	Current TO 300 PM
Adams County	1	Current TO 400 PM	Current TO 300 PM
Douglas County	1	Current TO 400 PM	Current TO 300 PM

County-specific Quantitative Precipitation Outlook	Precipitation Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	Current TO 400 PM SUN	Trace (95%) to 0.3" (60%) to 0.8" (15%)	ISSUED
Arapahoe	Current TO 400 PM SUN	Trace (95%) to 0.3" (60%) to 0.8" (15%)	ISSUED
Boulder	Current TO 400 PM SUN	Trace (80%) to 0.3" (40%) to 0.8" (10%)	LOW
Broomfield	Current TO 400 PM SUN	Trace (80%) to 0.3" (40%) to 0.8" (10%)	LOW
Denver	Current TO 400 PM SUN	Trace (95%) to 0.3" (60%) to 0.8" (15%)	ISSUED
Douglas	Current TO 400 PM SUN	Trace (95%) to 0.3" (60%) to 0.8" (15%)	ISSUED
Jefferson	Current TO 400 PM SUN	Trace (80%) to 0.3" (40%) to 0.8" (10%)	LOW
Foothills above 6500ft
Boulder	Current TO 400 PM SUN	Trace (75%) to 0.3" (30%) to 0.8" (5%)	LOW
Douglas	Current TO 400 PM SUN	Trace (75%) to 0.3" (30%) to 0.8" (5%)	ISSUED
Jefferson	Current TO 400 PM SUN	Trace (75%) to 0.3" (30%) to 0.8" (5%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.