Flash Flood Prediction Program

-	A "dry line" is approaching from the west but ahead of it ample moisture remains in place along the I-25 corridor to fuel storms as temperatures are now warming. Ahead of the dry line there will be a modest chance for thunderstorms, some of which may become strong to severe and could produce brief heavy rainfall.
-	As the dry air arrives from the west thunderstorm chances will diminish significantly. The drier air is currently just W of the Continental Divide and the progression of the drier air over the next few hours will be a determining factor on how the day will play out. Thunderstorms will be fast moving from S to N reducing the threat for heavy rainfall from a single storm. Training of thunderstorm cells may result in extended periods of heavy rainfall.
-	If thunderstorms initiate over the foothills instead of E of the I-25 corridor, Message 1's may need to be issued as brief heavy rainfall will accompany the stronger thunderstorm cells.

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.

A LOOK AHEAD: High pressure starts to build over the region tomorrow leading to dry conditions starting the week with temperatures in the upper 70's to low 80's through Wednesday. A slight chance Wednesday afternoon for widely scattered high-based thunderstorms with no heavy rainfall threat at this time.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	1130 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Arapahoe	1130 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Broomfield	1130 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Denver	1130 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Boulder	1100 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Douglas	1100 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Jefferson	1100 AM TO 400 PM	Trace (90%) to 0.3" (60%) to 0.8" (15%)	MOD
Foothills above 6500ft
Boulder	Current TO 400 PM SUN	Trace (80%) to 0.3" (50%) to 0.8" (10%)	LOW
Douglas	Current TO 400 PM SUN	Trace (80%) to 0.3" (50%) to 0.8" (10%)	LOW
Jefferson	Current TO 400 PM SUN	Trace (80%) to 0.3" (50%) to 0.8" (10%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.