textproduct: Cheyenne

KEY MESSAGES

- Winter Storm Warning now in effect for the Sierra-Madre and Snowy Ranges beginning early Wednesday morning and continuing through Thursday morning.

- Progressive pattern expected through the week with better chances of precipitation, but temperatures remaining above normal through the period.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 308 AM MST Wed Feb 11 2026

Clouds are slowly pushing in from the West but haven't made it to the far northeastern corner of the forecast area. As consequence Chadron is about 10 degrees colder than forecasted due to efficient radiational cooling. Temperatures should start to rise once cloud cover moves over there and acts like a thermal blanket as they block the terrestrial longwave and push the warmth back towards the surface. Today, a mid-level trough will push through the Intermountain West. Accompanying this trough is a warm front, which will act as the primary forcing mechanism for today's precipitation. The warm front is expected to pass through the mountains in the morning and sometime this early afternoon reach the I-25 corridor then entering the Nebraska Border by the evening time frame. For areas west of I-25 this warm front will lift the vapor particles and develop some snow chances throughout the day today. A band of Fgen looks to develop over the Sierra Madre and Snowy mountains. This band of Fgen will help increase local snow rates (primarily in the afternoon) to between half inch to inch per hour rates. Past 18z Southeast Wyoming will see another push of moisture mainly over Carbon and Albany county. With this surge of moistures we switch from Isentropic Descent to Isentropic Ascent according to the RAP. This additional lift of water vapor parcels will be the catalyst to produce precipitation chances for Central Carbon and Albany county. Given the altitude of Rawlins and Laramie combined with the timing of the moisture surge, this will most likely come down as rain at first and then change over to snow rather quickly. Rawlins may see a couple hundredths of precip while Laramie will probably only see a trace to hundredth or a light dusting of snow. As for the mountains, most of the hi-res Models have between 15 and 20 inches of snow for the Sierra Madres and between 10 to 15 inches for the Snowy range. The HREF gave a 10 percent chance of greater than 20 inches for the Sierra Madre range. The HREF gave a 10 percent chance for greater than 15 inches for the snowy range. Comparing the dayshift grids to the current run of the NBM, the 17 and 12 inches that current run seems reasonable and in line with Hi-res Guidance. However, if the FGEN band does set up over the mountains then the mountains will probably perform in that 90 to 95th percentile and see close to 30 and 20 inches for the Sierra Madre and Snowy ranges. Given the 700mb jet ramps up in the afternoon to increase downsloping winds, areas east of I-25 will likely not see any precip Wednesday afternoon and evening. However, another frontal boundary (possibly cold front) will push down from the North overnight to early Thursday morning. Given the winds and 700mb jet will have died down during this time and RH recovery looks to be about 85 percent. This frontal boundary should allow enough forcing to override the shallow dry layer for precipitation to reach the ground. NAEF's IVT parameter shows IVT over Southeast Wyoming and the Nebraska Panhandle to be in the 90th to 97 percentile from 00z to 12 Thursday. So there should be enough moisture to lift to create some light precipitation for areas east of I-25. The highest chances lie in the southern half of Platte and Goshen County stretching to Scotts Bluff and Morril county and then areas south of that. This mainly has to due with the timing of expected saturation and the timing of the forcing to lift the parcels. The isentropic lift will slowly disappear and the moisture plume will be out of our region after 18z Thursday. Precipitation may linger in the overnight period but chances really start to decrease after 00z Friday.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 1050 PM MST Tue Feb 10 2026

A stationary front near the Colorado border will slowly lift northeast across the area late tonight and Wednesday as a warm front. Periods of light snow, or light snow mixed with rain, are possible along Interstate 80 late Wednesday morning through the afternoon hours.

HAZARDS/WEATHER TRENDS: VFR conditions expected for the rest of the night with midlevel clouds and light winds for all terminals. Stationary front will begin lifting northeast as a warm front over the next several hours. Winds will shift into the southwest after by 12z and become gusty across the southeast Wyoming terminals. Added PROB30 groups to KRWL and KLAR for MVFR conditions and light snow/rain mix after 17z and through the afternoon.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 420 AM MST Wed Feb 11 2026

VFR conditions expected for the rest of the night with midlevel clouds and light winds for all terminals. Stationary front will begin lifting northeast as a warm front over the next several hours. Winds will shift into the southwest after by 12z and become gusty across the southeast Wyoming terminals. Added PROB30 groups to KRWL and KLAR for MVFR conditions and light snow/rain mix after 17z and through the afternoon.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Winter Storm Warning until 11 AM MST Thursday for WYZ112-114. NE...None.