textproduct: Cheyenne

KEY MESSAGES

- High winds continue this morning along the I-80 corridor from Elk Mountain to Sidney, with widespread gusts of 40 to 55 mph continuing for the remainder of the area through midday.

- Critical fire weather conditions are expected Saturday due to gusty winds, low humidity, and dry fuels. A Red Flag Warning is in effect for the Nebraska panhandle.

- Another round of high winds is possible in the wind prone areas Saturday night, then spreading to east central Wyoming and northwest Nebraska during the day on Sunday.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 400 AM MST Sat Jan 17 2026

The powerful upper level low continues to spin over Iowa this morning, keeping the strong 700-mb jet in place over the area sandwiched between this low and the stubborn ridge over the west coast. A narrow band of moisture on the southwest flank of the upper level low has moved across the area early this morning, producing scattered snow showers. However, drier air is starting to take over, pushing the good frontogenesis and moisture producing this light snow off to the south. As winds aloft have decoupled from the surface overnight, we have fortunately been enjoying a slight break from the extreme winds overnight, but it is still quite windy with widespread gusts of 40 to 55 mph, while gusts to 65 mph continue for the I-80 corridor between Elk Mountain and Sidney. The High Wind Warning was extended out to Sidney again this morning. 700-mb winds of 60 to 70 knots remain overhead, and models show pretty good subsidence along the I-80 corridor through midday, so we may be able to get these gusts down to the surface more consistently than previously though. The lowest confidence in this is in the city of Cheyenne, but did not want to leave a gap in the warning. The 700-mb jet will begin to weaken around midday, and we should see a break in the 60+ mph winds after that. In addition to the wind, an unusually dry airmass is moving in over the Nebraska panhandle today. Dewpoints as low as -10 to -20F are expected with precipitable water near the lowest percentile of climatology. This will push RH below critical thresholds, and lead to high grassland wildfire danger once again. The Red Flag Warning remains on track for these areas. Humidity should be a little too high in Wyoming, but with strong winds continuing, grassland wildfire spread will still be an issue anywhere without snow cover.

We should get a short break from High Winds this afternoon, but warm air advection will take over this evening as the ridge briefly amplifies ahead of another upper level shortwave/cold front diving down from the north. We probably won't get much of a boost in high temperatures, since all of the warm air advection aloft will take place overnight, but this will push winds up again, at least in the wind prone areas. The clipper system diving down over the northern Plains will come with a surface low, and this will trail a surface trough well to the southwest, boosting the cross-barrier pressure gradient this afternoon. Marginally high winds will be possible in the wind prone areas thanks to this low-level gradient. While the flow aloft will not be a very favorable direction (NNW), the low level gradients look strong enough to warrant another High Wind Watch beginning around sunset this evening.

The surface trough will slowly push off to the east overnight, pulling a weakly defined cold front across the High Plains Sunday morning. This will bring down the cross barrier pressure gradient, but it will come with yet another 700-mb jet behind it. This one looks a little weaker and narrower than yesterday's event, but we will be looking at another round of strong northwest winds over the Plains for Sunday. LREF median 700-mb winds exceed 60 knots at KCDR and KAIA Sunday morning, but there is some uncertainty in how far to the west this feature will spread. Subsidence looks decent enough to warrant spreading the High Wind Watch to Niobrara county and the northern Nebraska panhandle. If the 700-mb jet begins to appear a little stronger on its southern/western flank, this may need to be expanded into the southern NE panhandle and possibly other portions of southeast Wyoming.

We can say with reasonably high confidence that we don't expect high winds anywhere in the forecast area Sunday night into Monday morning. This probably won't last all that long, but we will be able to enjoy at least a short break from the wind. Concurrent with this will be another weak vort-max diving down aloft in northwest flow while a surface high pushes up against the mountains. Models are showing modest frontogenesis and some decent moisture overrunning the boundary Sunday night into Monday morning. The ceiling for this event is not particularly high, but there will be potential for some light snow mainly inside a Laramie/Wheatland/Kimball triangle. Cheyenne, for example, has about a 50% chance for a dusting of snow, and about a 20% chance for 1" of snow at this time. We will need to monitor this potential in the coming days.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 400 AM MST Sat Jan 17 2026

Warm air advection will resume Monday PM into Tuesday between shortwave troughs. This will likely produce another round of High Winds in the wind prone areas as pressure falls over the Plains. The usual gap wind areas have a 60 to 80% chance for high winds Monday night into Tuesday. We should also see temperatures briefly warm above seasonal averages Tuesday with widespread breezy to windy conditions.

After Tuesday, forecast confidence decreases considerably due to divergence in the ensemble suite. On Wednesday into Thursday, there is reasonable confidence in another clipper system moving through, knocking down temperatures, and bringing perhaps another chance for some very light snow. However, timing differences result in a fairly large spread in forecast highs on these days. This spread gets even worse on Friday into next weekend. Models are in good agreement showing the upper level ridge over the western CONUS beginning to break down during this time period, allowing Pacific moisture back into the northwest CONUS. At the same time, a strong arctic surface high will push southward into the northern Plains. While ensembles are in agreement on this general pattern, there are differences in where the moist jet stream sets up, and how far south the arctic high pressure can push. This results in a huge spread in forecast highs for Friday and Saturday. The spread between the 25th and 75 percentile high temperature forecast is 20 to 25F both days. Currently, about 20% of ensemble members are clustered into a camp pushing both of these features into the I-80 corridor. This scenario would be the coldest (highs in the teens and 20s Friday and Saturday) along with the snowiest. Another 20% are clustered into a scenario that keeps the ridge fairly strong over the western CONUS, keeping the Pacific jet off to our north and the arctic high at bay. In this case, we could expect highs in the 40s to even 50s, along with likely more chances for high winds. The remaining 60% of ensemble members are somewhere in the middle, which would likely mean a challenging forecast even at short lead times with an arctic frontal boundary stalling somewhere over the forecast area.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 430 AM MST Sat Jan 17 2026

A few lingering snow showers will clear out over the next few hours, but we may still see brief MVFR to IFR through about 15z this morning. Otherwise, high winds remain the primary hazard through the forecast period. NNW winds this morning will tilt more northwest and gradually weaken as the day progresses. Peak gusts should be in the morning today, generally 35 to 45 knots at most terminals, but a few gusts up to 50 knots can't be ruled out. All terminals except RWL should get a few hours of a break after sunset, but expect W to WNW winds to resume by midnight. LLWS may also be a concern overnight.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Watch from Sunday morning through Sunday afternoon for WYZ102. High Wind Warning until noon MST today for WYZ110-116>119. High Wind Watch from this afternoon through Sunday morning for WYZ106. High Wind Watch from this afternoon through Sunday afternoon for WYZ110-116. High Wind Warning until 5 AM MST early this morning for WYZ115. NE...Cold Weather Advisory until 10 AM MST this morning for NEZ002- 003-095-096. Red Flag Warning from 11 AM this morning to 5 PM MST this afternoon for NEZ434>437. High Wind Watch from Sunday morning through Sunday afternoon for NEZ002-003-095-096. High Wind Warning until noon MST today for NEZ020-054-055.