textproduct: Cheyenne

KEY MESSAGES

- Scattered, squall-like showers and snow-showers possible across much of the forecast area this afternoon.

- Gusty winds are on the decline, but a few breezes remain possible, particularly near any shower activity.

- Below average temperatures alongside a chance of light mixed precipitation moving into the weekend, with dry conditions and a notable warming trend to start next week.

SHORT TERM /THROUGH FRIDAY/

Issued at 222 PM MDT Wed Apr 2 2025

Areas of showers and snow-showers have been noted as of this update across the region, including a quick burst of moderate snowfall moving into the Rawlins area alongside a few rumbles of thunder just to the west of the region. Surface CAPE values around 500 J/kg and lapse rates in the 9-10 C/km range are fueling this activity, so don't be surprised if we continue to see activity prosper through this evening including a few squall-like showers/snow-showers that could produce locally gusty winds and lowered visibilities. Outside of this, winds have been breezy across the region, in the 40-50 mph range, but are beginning to lessen. This should continue through the evening, with a calm night in store before the next system impacts us to end the week. In fact, with winds as weak as they are expected, areas of fog could develop for portions of the border area between Niobrara/Goshen/Sioux Counties.

For tomorrow and Friday, an embedded upper-level shortwave within the larger overall trough will quickly swing across the region, with the aforementioned primary trough forming a closed low over the Desert Southwest, then traversing eastwards through the start of the weekend, while at the surface a cold front a surge of cold Canadian air will overspread from the north on Friday. This will give us an initial surge of precipitation on Thursday with a second wave then following with the boundary on Friday. Snow levels will hover right around 5000 feet through Friday afternoon, but should quickly descend with the cold air mass as very chilly mid-spring temperatures are expected behind the front, with widespread teens for overnight lows likely. As for the precipitation, most of Wyoming can expect snow to be the dominant precipitation type outside of the border area into the Nebraska Panhandle where rain or a mix is expected at first before transitioning fully over to snow by Friday evening. Thankfully with the bulk of the system much further to the south, significant accumulations are unlikely, with overall QPF totals around 0.1-0.25 inch. And with snow ratios below or just around 10-1 until Friday evening, snow accumulations should be limited to just a few inches at best, primarily accumulating on grassy surfaces or elevated surfaces thanks to warm ground and road temperatures from the mild weather we've had prior to this event. By overnight into Saturday morning, a few lingering showers could be possible, but the bulk of the activity will be on it's way out to begin the weekend.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/

Issued at 222 PM MDT Wed Apr 2 2025

Ensemble guidance is in solid agreement on the long term as we see upper level troughing departing the region and ridging taking over, allowing for a warming trend through the end of the long term. A shortwave will briefly disrupt this flow Monday into Tuesday and could bring a few isolated showers alongside some gusty winds (currently not quite strong enough to warrant high wind concerns), but after this departs a very dominant ridge will then overtake the western half of the US and allow for a notable warming trend well into the extended period beyond the long term. High temperatures by Sunday are already into the 50's, and should jump well into the 60's through the end of the long term. The 75th percentile of the NBM even shows a high of 71 on Tuesday, but this will be largely dependent on how much disruption to the ridging the aforementioned shortwave can produce and help to temper the warming we're expecting. Otherwise, the long-term will be quiet as we go from a seasonably cool start to the forecast period to a seasonably warm one to end the period.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1020 PM MDT Wed Apr 2 2025

The flow aloft will turn southerly tonight, with a weather disturbance bringing increasing chances for rain and snow on Thursday.

Wyoming TAFS...For Rawlins, scattered to broken clouds near 15000 feet will lower to broken at 5000 feet after 19Z, and to 2500 feet after 00Z, with light snow reducing visibilities to 4 miles.

For Laramie and Cheyenne, scattered to broken clouds from 8000 to 15000 feet will occur, lowering to 8000 to 10000 feet after 15Z, and to 800 to 2500 feet after 19Z, with light snow reducing visibilities to 2 to 4 miles. Winds will gust to 30 knots at Laramie from 15Z to 19Z.

Nebraska TAFS...For Chadron and Alliance, ceilings will range from 800 to 1500 feet until 15Z, with fog reducing visibilities to 1 to 3 miles, then clouds will be scattered near 15000 feet from 15Z to 19Z, then ceilings will lower to 4000 feet after 19Z, and to 2500 feet after 00Z, with light snow and rain reducing visibilities to 4 miles.

For Scottsbluff and Sidney, clouds will be scattered near 7000 feet until 15Z, with areas of fog developing, reducing visibilities to 1 to 4 miles and occasional ceilings near 800 feet, then ceilings will range from 7000 to 10000 feet after 15Z, and lower to 800 to 2500 feet after 19Z, with light rain, snow and fog reducing visibilities to 2 to 3 miles.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.