Flash Flood Prediction Program

-	The main area of low pressure that impacted the District earlier this week has now moved east of the area, but a cool northerly flow in place will continue to result in mostly cloudy skies and below average temperatures. Highs today will peak in the upper 50s on the plains.
-	An upper level disturbance will move into Western Colorado from the north today, which will keep most of the shower and thunderstorm activity confined to areas along and west of the Continental Divide. However, outflow from high country storm activity could trigger showers/thunderstorms across the foothills by mid-afternoon, and a few of these showers could potentially spread onto the adjacent plains by late afternoon. Western and southern portions of the District will be the most favored for seeing measurable rainfall.
-	Instability will be marginal on the plains this afternoon, which will limit the potential for thunderstorms. In addition, low level moisture will be marginal today with dewpoints in the upper 30s to near 40. However, storm motions will be rather erratic this afternoon due to weak and variable upper level winds. General storm motions will be west to east at 10-15mph, but if any thunderstorms manage to develop in the District, a low potential will exist for these storms to stall along boundaries and produce moderate to brief heavy rains. Shower/storm activity should quickly taper off by around sunset.

STORM RAINFALL POTENTIAL AND DURATION: Typical showers and weak thunderstorms will produce rainfall amounts of TR-0.2" in 10-30 minutes. An isolated stronger thunderstorm will be capable of producing rainfall of 0.2-0.5" in 10-30 minutes.

WORST CASE SCENARIO: Training of thunderstorms results in rainfall of up to 0.8" in 45-60 minutes.

A LOOK AHEAD: A warming trend will ensue on Thursday, but a disturbance passing south of the District will result in a chance of afternoon showers and thunderstorms. Conditions look marginal for a heavy rainfall threat at this time. High pressure will build over the District on Friday, resulting in further warming and drying with just a slight chance of isolated thunderstorms. The potential for thunderstorms may increase this weekend as southerly winds are projected to transport low level moisture from the southern plains into Eastern Colorado.

Location	Prime Time	30-Minute Rainfall and % Probability	Message Potential
Plains
Adams	400 PM TO 800 PM	Trace (70%) to 0.2" (40%) to 0.5" (10%)	LOW
Arapahoe	400 PM TO 800 PM	Trace (80%) to 0.2" (45%) to 0.5" (15%)	LOW
Broomfield	400 PM TO 800 PM	Trace (70%) to 0.2" (40%) to 0.5" (10%)	LOW
Denver	400 PM TO 800 PM	Trace (70%) to 0.2" (40%) to 0.5" (10%)	LOW
Boulder	300 PM TO 800 PM	Trace (75%) to 0.2" (40%) to 0.5" (10%)	LOW
Douglas	300 PM TO 800 PM	Trace (85%) to 0.2" (50%) to 0.5" (20%)	LOW
Jefferson	300 PM TO 800 PM	Trace (85%) to 0.2" (50%) to 0.5" (20%)	LOW
Foothills above 6500ft
Boulder	200 PM TO 800 PM	Trace (85%) to 0.2" (50%) to 0.5" (20%)	LOW
Douglas	200 PM TO 800 PM	Trace (90%) to 0.2" (55%) to 0.5" (25%)	LOW
Jefferson	200 PM TO 800 PM	Trace (90%) to 0.2" (55%) to 0.5" (25%)	LOW

MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.