Time: 902 AM Tue June 6, 2023 Forecaster: Justin Brooks ------------------------- Heavy Precipitation Outlook Flash Flood Prediction Program ------------------------- SUNNY THIS MORNING WITH ANOTHER GOOD CHANCE FOR AFTERNOON/EARLY EVE THUNDERSTORMS Once again, there is very little change to the overall pattern as another good chance remains for widespread storms across the District this afternoon and early evening. Dew points are currently all over the place with anywhere from mid 40’s to mid 50’s throughout the District and will likely hold in place through the rest of the day. These elevated surface dew points will suggest moderate to heavy rainfall, similar to yesterday, as storm movements once again remain minimal. This will bring a good chance for a quick 0.4-0.8" in 10-30 minutes. Training of rain showers could also play a key component today as multiple rounds of moderate showers could lead to rainfall in excess of 1” per hour today. The best chance for storms will be from 1-8pm. Storm motions will once again be slow to nearly stationary from the S/SW higher terrain, moving N/NE and onto the plains. Additional storms will also likley form along outflow boundaries, leading to some erratic storm movement. This storm motion, combined with good available moisture will result in a MODERATE likelihood of Message 1’s being issued today. This is also in part to an already saturated surface which will result in easy pooling of water and quick creek/stream rises leading to localized flooding. Storms today also have a good chance of producing some large hail, gusty winds, and frequent cloud-to-ground lightning. STORM RAINFALL POTENTIAL AND DURATION: Typical rain showers and isolated thundestorms will produce 0.2-0.4” in 10-30 minutes. A moderate to strong thunderstorm could produce 0.4-0.8” in 10-30 minutes. WORST CASE SCENARIO: A stalled moderate to strong thunderstorm, or a thunderstorm that anchors off an outflow boundary will have the potential to produce up to 2.4” in under 60 minutes. A LOOK AHEAD: Much of the same tomorrow as the chance for a heavy rainfall threat continues. A better chance for a few showers in the morning hours Wednesday with a good chance for widespread moderate to heavy rainfall with a slight chance for severe weather in the afternoon and early evening. This pattern holds Thursday, bringing another good chance of widespread moderate to heavy rainfall across the District. LOCATION PRIME TIME 30-Minute Rainfall and % Probability Message Potential Plains       Adams 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Arapahoe 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Boulder 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Broomfield 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Denver 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Douglas 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Jefferson 200 PM TO 800 PM 0.2" (75%) to 0.4" (50%) to 0.8" (25%) MOD Foothills above 6500ft       Boulder 100 PM TO 700 PM 0.2" (90%) to 0.4" (60%) to 0.8" (30%) MOD Douglas 100 PM TO 700 PM 0.2" (90%) to 0.4" (60%) to 0.8" (30%) MOD Jefferson 100 PM TO 700 PM 0.2" (90%) to 0.4" (60%) to 0.8" (30%) MOD MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS. MHFD Flood Prediction Center: 303-458-0789    F2P2 Website [http://udfcd.org/Flash+Flood+Prediction+Program]