| Message 2’s (NWS Flood/Flash Flood Watch) have been issued for the entire District and will be valid until midnight tonight. Cool temperatures with readings in the upper 70’s to lower 80’s currently is holding back the initiation of thunderstorms due to cloud cover this morning slowing daytime heating. Clouds have dissipated and good warming is underway, and thunderstorms are expected to develop over the next 1-3 hours and begin to impact the District later this afternoon and continue well into the evening with multiple rounds of showers and thunderstorms possible. Thunderstorms that develop later this afternoon and evening have ample moisture to work with and will be very capable of producing heavy rainfall that may lead to excessive runoff and flash flooding within the District. Storms will be faster moving today as upper level winds have increased with typical storm motions of around 20mph from SW to NE. Slower moving large thunderstorms or training of thunderstorm cells are the likely culprits for extended periods of heavy rainfall. Due to all of the rain yesterday it may not take as much rain today to produce excessive runoff and flash flooding. Heavy rainfall will be the primary threat from thunderstorms today, but large hail and gusty winds are also possible from stronger storms. |
WORST CASE SCENARIO: A slow moving strong thunderstorm or training of thunderstorm cells may result in up to 3.5” of rain in 60-90 minutes.
| County-specific Quantitative Precipitation Outlook |
Precipitation Time | 30-Minute Rainfall and % Probability |
Message Potential |
|---|---|---|---|
| Plains | |||
| Adams |
300 PM TO
1159 PM |
0.5" (75%) to 1" (50%) to 2" (25%) | |
| Arapahoe |
300 PM TO
1159 PM |
0.5" (80%) to 1" (50%) to 2" (30%) | |
| Boulder |
300 PM TO
1159 PM |
0.5" (75%) to 1" (50%) to 2" (25%) | |
| Broomfield |
300 PM TO
1159 PM |
0.5" (75%) to 1" (50%) to 2" (25%) | |
| Denver |
200 PM TO
1159 PM |
0.5" (75%) to 1" (50%) to 2" (25%) | |
| Douglas |
200 PM TO
1159 PM |
0.5" (80%) to 1" (50%) to 2" (30%) | |
| Jefferson |
200 PM TO
1159 PM |
0.5" (75%) to 1" (50%) to 2" (25%) | |
| Foothills above 6500ft | |||
| Boulder |
100 PM TO
1159 PM |
0.5" (80%) to 1" (50%) to 2" (25%) | |
| Douglas |
100 PM TO
1159 PM |
0.5" (80%) to 1" (50%) to 2" (25%) | |
| Jefferson |
100 PM TO
1159 PM |
0.5" (80%) to 1" (50%) to 2" (25%) |
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.