National Weather Service Forecast Discussion |
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697 FXUS65 KBOU 031803 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1203 PM MDT Fri Jul 3 2026 .KEY MESSAGES... - Critical fire weather conditions in South Park again today. - Isolated showers and thunderstorms possible this afternoon for portions of the northern plains. - Near normal temperatures with scattered showers and storms on July 4th. A few storms could become strong to severe. && .DISCUSSION /Through Thursday/... Issued at 548 AM MDT Fri Jul 3 2026 Another night of nocturnal convection brought a few late-night severe storms and heavy rainfall to our northeast counties once again. The heaviest rain was observed in locations that have seen multiple rounds of severe weather over the past few days across Logan and Sedgwick Counties. Between observations and radar totals showing between 1.5 to 2.5 inches falling along I-76 in these already saturated areas, a Flash Flood Warning was issued until 6AM along I-76 from Sterling to Sedgwick, as additional rainfall is expected for the next hour or so that could bring some flooding to small creeks, streams, roads, and poor drainage and low-lying areas. Beyond the overnight convection, the main story for today will be hot temperatures, and critical fire weather conditions taking hold across South Park once again, where a Red Flag Warning is in place from 12PM to 7PM for single-digit relative humidities and winds gusting to 25 mph. There is potential for some afternoon showers and storms to develop, mainly for areas along the Wyoming and Nebraska borders where the SPC has our three northeastern most counties in a Marginal Risk, with winds and hail being the main threat. We could also see some gusty outflows move from north to south across the plains in the evening from storms to the north. For the Fourth, increased low-level moisture and MLCAPE ranging from 1,000 to 2,500 J/kg+ across the plains, mixed with enough 0-6km shear to allow for supercells to develop, we are looking at potential for isolated to scattered strong to severe storms developing by the afternoon, with the SPC highlighting areas along the northern I-25 corridor eastward across the plains, where large hail and severe winds will be the main hazards. Be prepared to receive weather warnings if you plan to be celebrating outdoors on Saturday afternoon and evening! Hot temperatures and afternoon showers/storms will continue each day through the forecast period, with at least some improvements to fire weather conditions expected to keep critical fire weather conditions at bay, as we see a welcomed reprieve from single-digit relative humidity values after today. && .AVIATION /18Z TAFS through 18Z Saturday/... Issued at 1135 AM MDT Fri Jul 3 2026 Smoke will continue to impact slant range visibility today. We`re monitoring for potential virga and thunderstorms later this afternoon and evening. Chances remain too low at this time to include in the TAF, but a Prob30 for gusty winds and rain could be introduced with a later TAF package. The highest chance for virga will be around 23Z to 3Z, with a low chance for nearby thunderstorms around 3Z to 6Z. Winds today will generally be out of the northeast, with the exception of any outflow boundaries. Strong outflow is expected to push into DIA around 3Z this evening as a complex of storms moves through northern Colorado. Winds will turn more NW for the early overnight hours before turning SW for the early morning tomorrow. && .BOU WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 7 PM MDT this evening for COZ214. && $$ DISCUSSION...9 AVIATION...AP