Time: 1012 AM Sun May 3, 2020 Forecaster: Brad Simmons

Heavy Precipitation Outlook
Flash Flood Prediction Program

ANOTHER DISTURBANCE WILL KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR LATER TODAY AND TONIGHT
-With more sunshine to start the day today temperatures will recover nicely into the 70's to around 80 over the plains. Another upper level disturbance will pass along the CO/WY border area later today and tonight resulting in isolated afternoon and evening thunderstorm activity with chances for additional rain showers into daybreak Monday.
-Thunderstorm chances begin to increase over the higher terrain after 2 or 3pm with best chances for thunderstorms lower elevations from about 4pm to midnight. Storms that develop today will be more isolated and weaker than yesterday but will still move quickly from WSW to ENE at 30-40mph helping to limit point rainfall amounts. Light to brief moderate rain will accompany most storms with an outside chance for a stronger storm to potentially produce brief heavy rain, hail and gusty winds.
-After midnight thunderstorm chances decrease but a chance for isolated light rain showers continues possible into about daybreak Monday. Best chances additional light rainfall after midnight will be over the northern half of the District.
STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.1" of rain. Moderate to strong thunderstorms will have the potential to produce 0.1-0.4" of rain in 10-30 minutes.

WORST CASE SCENARIO: Moisture levels remain elevated and a surface wind convergence line sets up over the District allowing for stronger and slower moving thunderstorms to develop with the potential to produce rainfall rates of 0.3-0.8" in 10-30 minutes as well as severe weather in the form of hail and gusty winds.

A LOOK AHEAD: Temperatures on Monday will be a little cooler with highs either side of 70 degrees on the plains. The threat for isolated afternoon and evening thunderstorms will continue. Heavy rainfall is not expected at this time.

Location Prime Time 30-Minute Rainfall
and % Probability
Message
Potential
Plains      
Adams 400 PM TO 1159 PM
Trace (80%) to 0.1" (60%) to 0.4" (20%) LOW
Arapahoe 400 PM TO 1159 PM
Trace (75%) to 0.1" (50%) to 0.4" (15%) LOW
Boulder 400 PM TO 1159 PM
Trace (90%) to 0.1" (65%) to 0.4" (25%) LOW
Broomfield 400 PM TO 1159 PM
Trace (85%) to 0.1" (60%) to 0.4" (20%) LOW
Denver 400 PM TO 1159 PM
Trace (75%) to 0.1" (50%) to 0.4" (15%) LOW
Douglas 300 PM TO 1159 PM
Trace (75%) to 0.1" (50%) to 0.4" (10%) LOW
Jefferson 300 PM TO 1159 PM
Trace (75%) to 0.1" (60%) to 0.4" (15%) LOW
Foothills above 6500ft      
Boulder 200 PM TO 1159 PM
Trace (90%) to 0.1" (65%) to 0.4" (20%) LOW
Douglas 200 PM TO 1159 PM
Trace (75%) to 0.1" (50%) to 0.4" (10%) LOW
Jefferson 200 PM TO 1159 PM
Trace (80%) to 0.1" (60%) to 0.4" (15%) LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.