textproduct: Cheyenne

KEY MESSAGES

- Lingering snowfall possible this afternoon, subsiding into the evening hours with minimal accumulations expected.

- Winter-like temperatures in the teens to low 20s are expected by Saturday morning, creating a risk for outdoor irrigation and sensitive vegetation that has emerged from winter dormancy early.

- Critical Fire Weather conditions expected on Saturday with gusty winds and low humidity values, with further critical conditions possible Sunday and again Monday as humidities dive into the single digit values.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 241 PM MDT Fri Apr 17 2026

We saw some impressive snowfall rates finally this morning as banding activity moved across in the post-frontal environment. While snow did briefly bring down visibilities, overall accumulations were minimal with limited significant impacts outside of localized travel conditions. A few echoes are still seen on radar with light snowfall possible as this activity moves across the region, but this should be on the downward trend and exiting the region into the evening and overnight hours. For tonight, the combination of snowfall that continues to stick to the ground alongside the arctic airmass that has overspread the region will contribute to very cold temperatures, with overnight lows descending into the mid to low 20's and even some teens making an appearance. Don't be surprised if we see lows tank in the panhandle thanks to clearing skies.

Moving into the weekend, the main story will be the complete 180 in our conditions as we go from cool temperatures and precipitation to warming and fire weather concerns. The limited snowfall we did receive won't be enough to counter the dry conditions we've been having east of the mountains, and a Red Flag Warning is in effect for Saturday due to low RH values combined with gusty winds in the 25 to 35 mph range. Sunday will continue the drying trend as we see RH values bottom out into the single digit values, and while winds won't be nearly as strong under a weaker pressure gradient, our overall fire threat will remain high due to this dry environment. A Fire Weather Watch has been issued for Sunday, and will extend into Monday as overnight recoveries only peak at a paltry 35-45%, with daytime minimums once again into the single digits on Monday. Outside of fire weather, no other sensible weather concerns are anticipated under mostly clear skies with temperatures warming into the 50's on Saturday, and the return of 60's and 70's on Sunday.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 241 PM MDT Fri Apr 17 2026

The work week will begin under the influence of a longwave ridge centered over the Rocky Mountain region, placing us in mid-level zonal flow. Unsurprisingly this will result in well above average temperatures, with locations east of the Laramie Range in the 70s and low 80s, especially in our Nebraska counties. West of I-25, temperatures will be slightly cooler in the 60s. Fire weather will be the main concern on Monday as median RH values are around 10% east of the Laramie Range per LREF guidance. Ensemble guidance also has median wind gusts of 20-25 mph, so combined with plenty of dry fuels given that our recent system didn't provide much in the way of moisture, fire conditions look to be elevated at this time. Have issued a Fire Weather Watch for area along and east of I-25 for this reason through Monday evening.

Not much change for Tuesday, except for slightly weaker winds which should decrease the fire concerns. RH values will also be slightly higher in the 15-20% range. High temperatures look to be a about 5 degrees warmer than Monday considering the ridge axis is progged to be located over SE Wyoming and W Nebraska. Not exactly threatening daily record highs, but temperatures should reach 20 degrees above climatology.

Wednesday the ridge begins to progress to the east, placing us in a southwesterly flow regime ahead of a closed low located over Oregon and Northern California. High temperatures look to remain similar to those of Tuesday, however given weak forcing for ascent downstream of the closed low, we may manage to see some high-based convection. Ensemble model soundings indicate inverted-v profiles, so wind is more likely than any beneficial rainfall. This is also consistent with ensemble median PWAT values which are around climatology, suggesting the overall lack of moisture.

On Thursday, the closed low progresses into an open wave and lifts off to the north and east of our area, bringing us a series of vorticity maxima along the base of the shortwave, providing some greater forcing for ascent. At the very least, this should increase cloud cover over Southeastern Wyoming and Western Nebraska. There is a slight increase in PWAT (0.05" more) relative to Wednesday, however the bulk of the moisture remains well to our north and east, so precipitation chances appear low at this time, so will keep low PoPs in the forecast. Given the increasing cloud cover, we can expect temperatures to be 10-15 degrees cooler than Wednesday's highs.

Ensembles are hinting at a cold front pushing across our area sometime Thursday evening into Friday morning, so Friday is expected to be much cooler than the rest of the work week. With the general lack of moisture along with quasi-zonal flow, beneficial precipitation unfortunately doesn't look to accompany this front.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 519 PM MDT Fri Apr 17 2026

VFR conditions will prevail through the entire TAF period. High confidence that CIGS will remain aoa 10 kft. Northwesterly winds will decrease to 10-15 knots for the Wyoming terminals by 03Z, with slightly weaker winds for the Nebraska sites. NW winds will ramp up by Saturday morning with peak gusts ranging from 25-30 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning from 11 AM to 8 PM MDT Saturday for WYZ430>433. Fire Weather Watch from Sunday morning through Monday evening for WYZ417-418-430>433. NE...Red Flag Warning from 11 AM to 8 PM MDT Saturday for NEZ434>437. Fire Weather Watch from Sunday morning through Monday evening for NEZ434>437.