Time: 647 PM Thu June 22, 2023 Forecaster: Brad Simmons ------------------------- Internal Message Status Flash Flood Prediction Program ------------------------- MESSAGE 2’S CONTINUE VALID BUT MAY BE RESCINDED EARLY Message 2’s (NWS Flood/Flash Flood Watch) currently remains valid until midnight tonight but there is a good chance that the Watch will be rescinded early as the threat for heavy rainfall is lowering as we move into the evening and temperatures have cooled into the 60's to around 70. There will still be a good chance for showers and weak to moderate thunderstorms but nothing like the intense thunderstorms that impacted portions of the District earlier today with heavy rainfall, large damaging hail and even isolated tornadoes over Douglas County. New storms are staging to the W over the foothills and will progress eastward but with a cooler air mass in place the strength of the storms will be weaker than earlier today, and it will not take as much rain to produce runoff as the ground is saturated and creeks and streams are still running high. Best chances for additional rain showers and weak to moderate thunderstorms will be through about 9pm. If NWS cancels the Flood/Flash Flood Watch, Message 4’s (All Clear) will be issued. STORM RAINFALL POTENTIAL AND DURATION: Rain showers and weak thunderstorms will produce a trace to 0.3” of rain. Moderate thunderstorms will have the potential to produce rainfall rates of 0.3-0.7” in 10-30 minutes. WORST CASE SCENARIO: Should a strong thunderstorm be able to develop heavy rainfall of 0.5-1.5” in 10-30 minutes continues possible. COUNTY MESSAGE VALID TIMES PRIME TIME Boulder County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Jefferson County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Broomfield County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Douglas County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Adams County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Denver County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM DIA 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Arapahoe County 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM the City of Aurora 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Arvada 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Wheat Ridge 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM Lakewood 2 1200 PM TO 1159 PM 1200 PM TO 1100 PM County-specific Quantitative Precipitation Outlook PRECIPITATION TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Arapahoe Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Boulder Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Broomfield Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Denver Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Douglas Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Jefferson Current TO 1159 PM THU 0.1" (60%) to 0.3" (30%) to 0.7" (10%) ISSUED Foothills above 6500ft       Boulder Current TO 1159 PM THU 0.1" (80%) to 0.3" (50%) to 0.7" (20%) ISSUED Douglas Current TO 1159 PM THU 0.1" (80%) to 0.3" (50%) to 0.7" (20%) ISSUED Jefferson Current TO 1159 PM THU 0.1" (80%) to 0.3" (50%) to 0.7" (20%) ISSUED MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]