Flash Flood Prediction Program

-	A passing upper level disturbance is expected to increase the thunderstorm activity today over the District. Ample moisture remains at the surface to fuel storms and in tandem with daytime heating thunderstorms will once again develop over the higher terrain to the W of the District by around noon.
-	Thunderstorm chances will increase over the plains between 1-3pm. Prime time for stronger thunderstorms will be between 3-9pm. An additional round of showers and possibly a weak thunderstorm continues likely until midnight with a few lingering isolated light rain showers into early Tuesday morning. Thunderstorms that develop today will be very capable of producing moderate to heavy rainfall and may become severe with large hail and gusty winds being the primary threats.
-	Upper level steering winds remain relatively light from NW to SE at 10-15mph. Outflow boundaries and gust fronts may act to slow down or briefly anchor storms and may result in erratic storm motions at times. Temperatures today expected to reach the lower 90's over the plains.

STORM RAINFALL POTENTIAL AND DURATION: Weak to moderate thunderstorms will produce 0.1-0.4" of rainfall. Strong thunderstorms will have the potential to produce 0.4-1.2" in 10-30 minutes.

WORST CASE SCENARIO: A nearly stationary strong thunderstorm may result in up to 2.5" of heavy rain in 45-60 minutes.

A LOOK AHEAD: Behind the disturbance on Tuesday temperatures will be cooler in the upper 70's to lower 80's for highs. The best chances for thunderstorms will be pushed southward but there will still be widely scattered afternoon thunderstorms with the potential to produce heavy rainfall.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Arapahoe	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Broomfield	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Denver	300 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Boulder	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Douglas	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Jefferson	200 PM TO 900 PM	0.1" (90%) to 0.4" (60%) to 1.2" (30%)	HIGH
Foothills above 6500ft
Boulder	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	HIGH
Douglas	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	HIGH
Jefferson	100 PM TO 900 PM	0.1" (95%) to 0.4" (65%) to 1.2" (30%)	HIGH

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.