textproduct: Western and Central Wyoming

KEY MESSAGES

- Warming trend, dry conditions, and elevated to near critical fire weather conditions through Wednesday. Wednesday to be the windiest and warmest day of the week for the most critical day of concern.

- Next system pushes in by late Wednesday increasing precipitation chances and cooler temperatures for remainder of the work week and into the weekend.

UPDATE

Issued at 1245 PM MDT Sun Apr 19 2026

Forecast still on track for the most part in the short term, although winds were increased east of the Divide for Monday and Tuesday bringing more critical of fire weather concerns. Otherwise, the next system for Wednesday onward looks to be trending more towards this past system. The EC has the closed upper level low become more of an open wave once again with a more progressive approach and as such, less impacts as it was previously. It is still something to keep an eye on but don't expect a drought buster of any kind from it. Stay tuned for updates in the coming days.

DISCUSSION

Issued at 246 AM MDT Sun Apr 19 2026

Upper level ridging will dominate the forecast for the next few days. Today, the warming trend continues with highs peaking in the mid to upper 60s across most lower elevations. The main weather concern will again be fire weather given the dry environment; relative humidity will drop to around or below 10 percent for much of the area this afternoon. However, lighter wind will play a mitigating factor with gusts on the higher end generally below 25 mph. Still, there will likely be isolated pockets of critical fire weather conditions where wind is maximized, particularly across portions of fire zones 283 and 289.

Warm and dry conditions continue on Monday, with highs peaking another 5 to 10 degrees warmer than today. Wind will be slightly increased as a subtle shortwave to our north induces a weak surface low across northeastern Wyoming. This may lead to the need for fire weather highlights across portions of central Wyoming, though again wind will be the limiting factor for a more widespread event.

The ridge will begin to compress on Tuesday as an upper low over the Pacific begins to push into California. Highs will reach their warmest of this stretch, peaking into the mid/upper 70s west of the Divide and 80s east. An increased southwesterly wind will lead to more widespread elevated to critical fire weather conditions. There will likely be enough moisture and upper jet support for at least isolated convection over western Wyoming Tuesday afternoon, though most of the area will remain dry.

Confidence is increasing for the low to reach Wyoming on Wednesday. If it stays on track, this should return widespread chances for precipitation as it passes over the area through Thursday. However, first up for most of the area will be strong southwesterly wind on Wednesday afternoon ahead of the associated cold front. This period will need to be watched for potential wind or fire weather highlights. Guidance is also suggesting a couple of robust waves trailing along the backside of the main low, perhaps extending cooler and (potentially) wetter conditions through the end of the week. This is corroborated by ensemble cluster guidance currently showing anomalously low 500 mb heights through next weekend. Hopefully this brings much-need moisture to the area, though details at this range are still uncertain.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 451 PM MDT Sun Apr 19 2026

VFR conditions prevail through the period with high pressure over the area. Winds are diurnally driven, with winds generally decreasing overnight and increasing for Monday afternoon. Passing high clouds overnight, but otherwise a clear to mostly clear sky through the next 24 hours.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts.

FIRE WEATHER

Issued at 1245 PM MDT Sun Apr 19 2026

Elevated fire weather for this Sunday afternoon as the winds will just not be that strong to warrant even near critical conditions. However, winds have increased for Monday and Tuesday afternoons warranting red flag warnings for parts of eastern Fremont/Sweetwater Counties to much of Natrona. mainly west to southwesterly winds look to gust up to 30 to 35 mph with relative humidity values hovering around the 10 to 15 percent as afternoon high temperatures increasingly warm well above average once again. Wednesday afternoon looks to be the most critical fire weather day as the humidity maintains while winds increase further as the pressure gradient tightens ahead of the next system and associated cold front. This will come with a wind shift post frontal passage with timing a bit uncertain at this time ranging from the mid afternoon to early evening hours.

RIW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM to 8 PM MDT Monday for WYZ280-289.