Area Forecast Discussion

KEY MESSAGES

- Areas of morning fog northeast plains.

- Heating up today with isolated and gusty afternoon/early evening storms.

- Critical fire weather conditions across portions of the plains today, with widespread critical fire weather conditions expected in fuel-prone areas by Tuesday and Wednesday.

- Hottest temperatures this weekend, and then again Tuesday and potentially Wednesday. Highs generally in the mid 90s across the I-25 Corridor and plains, but near 100 possible over the northeast plains Tuesday.

- Brief respite in the heat Monday, and then increasing heat relief late next week.

DISCUSSION /Through Friday/

Issued at 221 AM MDT Sat Jun 6 2026

We'll remain under the influence of an upper level ridge today, with yesterday's slight cooling all but gone by this afternoon under the influence of warm advection and strong daytime heating. Despite the ridging, there is still sufficient low and mid level moisture (even some morning fog over the northeast plains) to keep isolated storms in the forecast this afternoon and early evening. The main feature of these will be gusty outflow winds to 50 mph given DCAPE increasing to near 1400 J/kg, but a couple storms could also bring briefly heavy rain and small hail considering a few hundred J/kg of MLCAPE and modest precipitable water to work with. With southerly breezes increasing, fire danger will as well - see more details in the Fire Weather Discussion section. High temperatures will soar into the mid 90s across most of the plains, but we think Denver's official high will be just a couple degrees shy of the record of 95F last set in 2018.

For Sunday, we'll likely add on a degree or two with more of a downslope component and a drier airmass spreading in from the southwest. However, we'll still likely be at least a couple degrees shy of the record high of 98F in Denver. That said, it will be hot and extra precaution should be taken if planning outdoor activities this weekend. We'll be just shy of Heat Advisory criteria.

We still expect a brief break from the heat on Monday, with high temperatures settling back into the 80s for the most part (the deterministic forecast lies on the warmer side of most guidance). In addition, the introduction of low level moisture will bring a return chance of afternoon and evening thunderstorms.

Tuesday is still shaping up to be a blast furnace type day with gusty southwest winds and hot temperatures. The increase in wind and temperatures will be supported by strengthening southwest flow aloft as Colorado lies in between a stronger trough entering the western U.S. and a dominating ridge centered over the Southern Plains. While guidance has "cooled" ever so slightly, we still think a couple of our lowest elevations on the northeast plains have a reasonable (50-60%) chance of reaching 100F. Denver should reach the mid to upper 90s, so the record of 95F is in jeopardy. Beyond that, there is still uncertainty to how fast the next trough pushes across the northern U.S. and thus how quickly we'll start to cool. A few runs are now cooling things off a little by Wednesday already, while there is more agreement that stronger cooling arrives Thursday and especially Friday and Saturday. The deterministic forecast again lies on the warmer side of the solutions, so likely we'll end up a little cooler than the current forecast by the time we reach Thursday and Friday.

AVIATION /18Z TAFS through 18Z Sunday/

Issued at 1221 PM MDT Sat Jun 6 2026

The TAFs are complicated today due to the continuation of weak of convection over the mountains with possible initiation east and/or south of Denver, but VFR conditions will prevail through Sunday. Currently, convection over the Front Range mountains and foothills is fairly weak. On shower generated a single flash of lightning so far, and just 10-20% of lightning the rest of the afternoon. This convection shouldn't survive much as it moves slowly east off the foothills. The exception could be BJC which is why the PROB30 for SHRA is in place starting 19Z. The convection and any gust front it produces is likely to shift winds to the west at BJC this afternoon but once the gust front moves east of BJC, convective potential becomes too low to mention in the TAF, which will be after 22Z. DEN and APA have better chances of being impacted by weak convection, and definitely by virga, but probably not until after 21Z. The better chances of convection impacting DEN and APA will be later this afternoon into the early evening, with potential for gusts over 30 kts near any convection that gets going. The winds will also be tricky at DEN and APA, complicated by any convection. We don't think any gust front from the mountain/foothills convection will reach DEN, but convection over the Palmer Divide, or convection that forms along a gust front moving off the Palmer Divide could shift the winds from ESE to S or SW at DEN and APA, again with gusts up to 30 kts. All this detail is really hard to capture in the TAF, the best we could do is the PROB30 for -SHRA and variable gusty winds to 35 kts. As mentioned however, the most likely gust front wind direction would be SW, S or SE this afternoon/evening. The other uncertain part of the TAF are the SE winds after 02Z. Those winds in the model output are forced by convection southeast of APA and DEN. The CAMs all have some version of these winds and have for the last 6-7 runs, which is why we included them in the TAFs. However, if convection doesn't form, the SE winds won't be as strong and we'll just see normal drainage winds out of the south 10-15 kts after midnight.

Sunday looks like a very hot day but much lower chances of any meaningful impacts from convection at any of the TAF sites. Winds look to be WNW at 10 kts or so in the afternoon, and for now we do not expect any gust fronts to form.

FIRE WEATHER

Issued at 221 AM MDT Sat Jun 6 2026

Locally critical fire weather conditions are expected to develop today as fuels over some of the plains would still be receptive per the latest updates from land managers. Overall, conditions are not terribly ripe for rapid fire spread however with marginal winds and humidity values, but we'll continue to highlight the threat with the existing Red Flag Warning for portions of the plains northeast of Denver.

Winds decrease over most of the plains for Sunday, so despite even warmer temperatures and lower humidities, we do not anticipate any highlights at this time. Meanwhile, mountain areas will see increasing winds and dryness, but fuels there are labeled as mostly not critical.

More widespread critical fire weather conditions will likely (>70% chance) develop by Tuesday. Wind gusts of 30-40 mph will combine with record heat and 6-12% humidity over most of the forecast area. We'll continue to seek input from land managers regarding fuel status updates given recent drying trends, as Tuesday has potential to see extremely critical conditions given the above mentioned parameters.

BOU WATCHES / WARNINGS / ADVISORIES

Red Flag Warning until 7 PM MDT this evening for COZ242>245-248.