textproduct: Cheyenne

KEY MESSAGES

- Above-average temperatures and low precipitation chances remain in place across southeast Wyoming and western Nebraska on Monday into Tuesday.

- Winds will increase across Southeast Wyoming Tuesday into Wednesday, increasing fire concerns.

- Greater precipitation chances return to Southern Wyoming and Western Nebraska into the weekend, confidence on how much precipitation we will see remains low.

SHORT TERM /THROUGH TUESDAY/

Issued at 225 AM MDT Mon Apr 6 2026

Overnight conditions remain mild and tranquil as Southern Wyoming and Western Nebraska remain in a northwesterly flow regime downstream of a longwave ridge located over the western third of the country. As we are located at the inflection point between the aforementioned ridge and a longwave trough over the eastern third of the country (a favorable location for ageostrophic convergence aloft), we remain under the influence of a 1040 mb surface high located over Montana and North Dakota resulting in broad, 5-10 knot E/ENE surface winds.

Later in the afternoon/early evening on Monday, a weak backdoor cold front will move in from the northeast, resulting in ESE surface flow along and east of the Laramie Range, resulting in an increase in cloud cover post FROPA. However, given dry low-levels with 50th percentile RH values around 30%, no precipitation is expected at this time.

The mid-level ridge will begin to dampen as we head into Tuesday and flow will become more zonal. Due to downsloping, our wind speeds will also begin to ramp up on Tuesday afternoon. While random forest guidance generally keeps winds below high-wind criteria, high- resolution ensemble guidance has mean gusts of 15-20 mph east of the Laramie Range in addition to RH values < 25%, so will mention fire concerns during this time especially with above-average high temperatures in the 60s. Some weak mid-level instability is also progged (SBCAPE around 100 J/Kg) into Tuesday afternoon with forecast soundings showing an inverted-v profile with surface dewpoint depressions of 45-50 degrees, so any convection will likely produce gusty winds rather than any beneficial precipitation. This will exacerbate fire concerns in the vicinity of any high-based convection.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 250 AM MDT Mon Apr 6 2026

Models in reasonable agreement through the weekend and continue to show a strong upper level low passing well north of Wyoming and western Nebraska Tuesday night and WEdnesday. Outside of a few showers across the area, the primary concerns will be strong gusty winds Wednesday and fire weather concerns. 700mb winds will increase to over 50 knots by midmorning Wednesday with excellent subsidence for a few of the wind prone areas. We're starting to get out of "gap wind season", but the associated cold front and increasing 700mb flow could result in some gusts over 58 MPH for Arlington, Elk Mountain, and the I-80 Summit late Tuesday night through mid afternoon on Wednesday. In-house wind guidance is not completely on board and show mainly elevated wind gusts between 45 to 55 MPH, likely due to the poor surface pressure gradients with this event. Kept wind gusts near criteria, especially after midnight early Wednesday morning through noon Wednesday. Otherwise, the best chance for precipitation during this system may be later on into Wednesday evening across the high plains, once the primary upper level low moves eastward into the Great Lakes region.

As we head into late week, models are starting to show a pattern that's more consistent with a typical spring time weather pattern across the Intermountain West, with upper level troughing digging further south across the California coastline and Great Basin Region. Southern branch of the polar jet looks to become a little more active late in the week as several disturbances lift northeast across the Front Range. Although not synoptically impressive, surface based convection will likely be more of a forecast topic in the coming days. Agree with the previous forecasts and current ensemble guidance with increasing POP with possible thunderstorms by Friday and Saturday. In addition, NAEFS mean PWAT over the Front Range is between the 90th and 95th percentile (0.50 to 0.75 inches) from Friday through Saturday. This is likely not only due to surface moisture advection as winds shift into the east, but also moisture advection aloft ahead of the main Pacific system near the west coast. Widespread showers and thunderstorms appear unlikely since the bulk of the mid to upper level energy stay to our south. Regardless, will likely see widely scattered to scattered convection at the very least in this pattern. Kept thunder out of the forecast for now due to unknown amount of cloud cover, which may limit deeper convection. Even with brief cool downs behind each disturbance, very little impact on high temperatures expected with above average temperatures through the end of the week and into the weekend...generally in the 60s to low 70s. Saturday looks like the warmest day based on the Grand Ensemble with highs in the upper 60s to mid 70s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1131 AM MDT Mon Apr 6 2026

Northwest flow aloft will continue. Scattered to broken clouds near 15000 feet will prevail, with ceilings near 5000 feet at Sidney after 15Z Tuesday. Winds will gust to 29 knots into tonight, then will gust to 30 knots after 13Z Tuesday, except at Scottsbluff.

CYS WATCHES/WARNINGS/ADVISORIES

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