textproduct: Cheyenne

KEY MESSAGES

- Accumulating snow will continue above 7000 ft this morning. Snow levels may lower down to 5500 to 6000 feet briefly before precipitation ends later Thursday morning.

- A growing-season-ending freeze expected Thursday night into Friday morning across the entire area.

- Drier and milder weather expected this weekend into early next week.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 200 AM MDT Thu Oct 15 2026

First winter-like Pacific storm ongoing across southeast Wyoming with mainly rain below 6000 feet for far eastern Wyoming and western Nebraska early this morning. It is currently snowing in Laramie with a temperatures of 32 degrees, so snowlevels are likely between 6500 to 7000 feet given Cheyenne's current temperature at 100 AM of 38 degrees. The mountains and I-80 Summit are snowing moderately to occasionally heavy early this morning with accumulations on grassy surfaces, bridges, and overpasses. Current Winter Weather Advisory looks good and not planning to make any changes at this time. Band of moderate precip is colocated with the TROWAL feature/wrap around precip band which is currently over Albany county and extends northeast into east central Wyoming and the northern Nebraska Panhandle. This band is slowly translating eastward over the I-25 corridor, with the eastern extent of the band early stationary over the eastern plains. Forecast appears on track, at least the timing and expected snowfall/amounts. Still expect a transition to snow around elevations of 6000 feet and possibly as low 5500 feet before the precipitation ends later this morning. High res models and synoptic models have finally backed off on their massive QPF amounts, showing amounts that are a little more reasonable with this type of system. Models also show the storm system trending more progressive and exiting the area as early as 10:00 am to 1:00 pm today. This makes sense given the position of the northern branch of the jet stream and associated upper level trough/upstream kicker sliding south across the northern plains this morning. After trending QPF higher the last couple of days due to model persistence/consistency with higher precip amounts, lowered QPF back in line with a more faster moving storm system. Snowfall should be similar to the previous forecast with a slight lowering of snowfall totals. The only forecast concern is possible areal extensions of the Winter Weather Advisory for portions of I-25, southern Laramie Range foothills, etc; and maybe an upgrade to a Warning for the I-80 Summit and Snowy Range. However, confidence is limited at this time.

Based on current trends, expect precip to end around noon (earlier west of I-25) with skies quickly clearing behind the upper level low as it becomes an open wave trough and exits to the east. Will likely see some sunshine by mid to late afternoon, so even with 700mb temperatures below freezing, expect high temperatures to recover somewhat into the mid 60s across western Nebraska, and remaining in the 40s for most of southeast Wyoming. Clear skies and good radiational cooling with set the stage for our first hard freeze. It's nearly a certainty at this point that most places will see low temperatures late Thursday night and Friday morning below 30 degrees, especially with the Canadian upper level trough diving south with another cold front diving south across the plains with a 1036mb surface high behind it. Upgraded the Freeze Watch to a Warning for areas west of the Interstate 25 corridor and Converse and Niobrara counties. Will keep the Watch going further south and east after collaboration with neighboring offices. Kept temperatures tonight around the NBM and Grand Ensemble 25th percentile. Will likely see some mid to upper teens for the more sheltered high valleys, especially if any snow accumulation remains over the valleys of central and south central Wyoming.

All models show the eastern Pacific upper level ridge axis sliding eastward into the Intermountain West during the day. Expect drier weather and mostly sunny skies for the forecast area with temperatures about 10 degrees warmer compared to the last few days. High temperatures in the 50s expected during the afternoon with light southerly winds. Not as cold Friday night, but most of western Nebraska and south central Wyoming will see low temperatures below or near freezing once again.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 115 AM MDT Thu Oct 15 2026

The Intermountain west starts to take a temporary break from the active weather pattern starting Saturday morning. A slow moving ridge starts to set up and meander every so slightly towards the central plains. The region will gradually warm up due to this ridge but don't expect any summer like temperatures for the rest of the season. The global models have 700mb temperatures only warming up to between 6-10c through the next week after this freeze from a visit from a polar airmass. With the sun angle slowing dropping I'd wager that 80 degree days are probably done for this forecast area. Instead the greater gamble would be on wearing shorts or pants in the morning as temperatures start out in the 30's and 40's and climbing into the 60's and 70's by the afternoon. By the mid-week another low pressure system is progged to slide down the west coast as another low is just hanging around the east coast to put the Intermountain West on the forward edge of an Omega block centered over the central plains. The low off the west coast however will be a critical player to our regions forecast. The cyclonic rotation will be feeding moisture into our region to keep the afternoon RH values high enough to not present any current fire weather concerns while also stacking the cards on any needed precipitation reaching the ground as multiple shortwaves move past the Rockies for some precipitation chances late next week.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1130 PM MDT Wed Oct 14 2026

A storm continues to roll through the region, this will bring numerous aviation impacts across all terminals in our CWA through the overnight hours. One of which are low CIGs, expect a continuation of MVFR to IFR CIGs, possibly down to LIFR at times, for all the sites. Another is precipitation moving through, for the southeast Wyoming terminals as colder air plunges in, this precipitation is or is transitioning to snow or a snow/rain mix. This snow may reduce VIS significantly, possibly down to IFR VIS. However, rain is not expected to transition to snow across the Nebraska Panhandle. Winds will become northerly as the storm begins to move off to the east, as it does, look for winds to ramp up with gusts 20 to as high as 35 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Freeze Watch from late tonight through Friday morning for WYZ107-108-117>119. Freeze Warning from midnight tonight to 9 AM MDT Friday for WYZ101-102-104>106-109>111-113-115-116. Winter Weather Advisory until noon MDT today for WYZ110-112- 114>116. NE...Freeze Watch from late tonight through Friday morning for NEZ002-003-019>021-054-055-095-096.