National Weather Service Forecast Discussion |
Thornton Weather Forecast Today's Forecast Story |
126 FXUS65 KBOU 081146 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 546 AM MDT Wed Jul 8 2026 .KEY MESSAGES... - Scattered to numerous thunderstorms, with a few strong to severe storms, are expected from the Front Range eastward today and Thursday. - Prolonged period of hot temperatures arrive Saturday, lasting through at least Tuesday. Thunderstorm chances remain low during this period. && .DISCUSSION /Through Tuesday/... Issued at 202 AM MDT Wed Jul 8 2026 Storms are expected to form over the foothills and I-25 corridor early this afternoon, progressing eastward throughout the afternoon and early evening. The strength and coverage of these initial storms near I-25 and the urban corridor will depend heavily on surface moisture. Some of the high res models have the higher dewpoints mixing out and pulling east in the early afternoon, which will hinder storms. Others, keep the moisture closer to the foothills. If the surface moisture does end up staying further west, we could see a few isolated strong to severe storms near the I-25 corridor, with the coverage and intensity of storms increasing as they move east. While strong winds will be the primarily hazard, mid level lapse rates and shear will be large enough that we could see a few storms produce severe sized hail. The threat for strong winds will increase later in the event as storms start to merge together in our eastern plains counties. Isolated areas could see periods of heavy rainfall as well with these storms. This activity is expected to exit our area by the late evening. On Thursday, it looks like we could see a Denver Cyclone set up and a weak disturbance move through the flow aloft. The east/southeasterly surface winds will keep dewpoints on the higher end for a good portion of the plains. These ingredients will combine to produce scattered to numerous thunderstorms Thursday afternoon. Once again, the main threat will be strong winds, particularly in our eastern counties, but we could see a few initial supercells which produce severe sized hail in the afternoon. I do want to put a caveat in here though that with the decent thunderstorm coverage we`re expecting today, outflow boundaries will likely linger somewhere over the area early Friday, which could impact initial conditions and the location of convective development for Thursday afternoon. We could see some additional thunderstorm development on Friday, but coverage and confidence in storms is lower compared to today and tomorrow. The upper level ridge will strengthen and shift north and west starting Saturday, putting the center of the high in the Colorado/Wyoming/Utah area for the weekend. Models are currently indicating that this ridge could strengthen to around 600dm (which is very strong). The ridge will sit over our area through at least the middle of next week. Strong subsidence under the upper level ridge will act to limit rain chances for this weekend and into the middle part of next week and will allow for clear skies, sunshine, and plenty of warming. We do have 2 things that could help us to keep temperatures below record breaking levels. The first is that models are actually keeping the warmest temperatures aloft to our west and north during this time period. And the second is that surface winds look like they may have more of an easterly component than a westerly component. This will provide weak upslope rather than the warm,dry downslope conditions that we see with westerly surface winds. With this being said, we`re still looking at a prolonged period of above normal temperatures for the whole area, but we may be able to escape record breaking high temperatures. && .AVIATION /12Z TAFS through 12Z Thursday/... Issued at 428 AM MDT Wed Jul 8 2026 West/southwest winds will gradually turn northwest then northeast throughout the morning. Thunderstorms are expected to form in the higher elevations and foothills around noon before progressing east towards the terminals. The most likely timing for storms this afternoon will be 19Z-23Z at KBJC and 20Z to 24Z at KDEN and KAPA. Storms will be scattered and intermittent during these time periods, producing gusty and variable winds. This activity is forecast to move out of the TAF sites by 00Z, with a chance for a few lingering showers or storms. In the evening, outflow from the storms to the east and northeast could impact the airports in the mid to late evening. However, confidence in wind speed and wind direction from any outflow boundaries are low. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...AP AVIATION...AP