textproduct: Cheyenne

KEY MESSAGES

- Red Flag Warning is in effect from 11 AM Saturday through 9 PM Sunday for all of southeast Wyoming for very low humidities and significant gusty winds.

- Hot temperatures continue through the start of the week before a pattern change begins to occur as precipitation chances start to rise and temperatures fall, dropping to below normal by the later half of the week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 220 AM MDT Sat Aug 8 2026

A warm weekend on tap as we see temperatures back into the 90's to triple digits alongside the atmosphere attempting to produce precipitation, and of course we can't forget smokey conditions promoting poor air quality as well. Through the weekend our CWA will be dominated by upper level high pressure over the Four Corners, causing flow aloft from the west to northwest. This will naturally continue to bring wildfire smoke across our area from the Pacific Northwest, with an Air Quality Alert in place for all of our Wyoming zones through Monday afternoon. Also in effect for our Wyoming zones is a Red Flag Warning through Sunday evening as dry air and breezy conditions continue to promote a critical environment. Daily RH values in the teens to single digits are expected, with poor overnight recoveries tonight only in the 30-40% range (which may be generous given how poor our recoveries have been the past several days). Meanwhile, our chances of precipitation may start to increase beginning later this weekend, but don't expect a pattern change that will dramatically alter our hot and dry conditions just yet. PWAT values for today will be well below normal, by around 20-40%, and a classic inverted V signature is shown in forecast soundings for the area. This environment will only be able to produce a dry thunderstorm or gusty virga shower at best with precipitation at the surface unlikely. Sunday though we'll see a bit more moisture begin to move into the region, and PWAT values should be at or just above average at around 0.75-1". While soundings still show an inverted V signature and dry lower level conditions will likely continue to limit what we can get to the surface, there's at least a bit more hope that somewhere could see a small amount of rainfall. But what's likely is that we'll see another round of gusty virga showers and/or dry lightning, further complicating our critical fire weather environment. Overall more of the same, but hopefully a respite is in sight as we move into the long term.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 250 PM MDT Fri Aug 7 2026

A suppressed ridge pattern will continue throughout the majority of the long-term forecast period. Monsoonal ridging throughout the weekend will gradually subside, with the 500mb jet generally positioned from the Washington/Oregon cascades and stretching across the northern Rockies into the high plains of Montana and northern Wyoming. South of this feature, gradually deepening moisture will spread across the central and southern Rockies from the Four Corners eastward through the high plains. PWAT values at selected sites across southeast Wyoming and western Nebraska all show a steady rise each day from Sunday through the end of the week. This will lead to increasing coverage of showers and thunderstorms each day. By the Wednesday-Friday timeframe PWAT normalized anomalies in ensemble guidance will run around 2 to 2.5 standard deviations above the mean. This will result in high confidence of afternoon thunderstorms, some of which may contain heavy drenching downpours. Despite better thunderstorm chances, severe weather remains generally unlikely in southeast Wyoming with mostly light westerly flow in the mid and upper-levels present. Farther east into the Nebraska Panhandle, some faster flow aloft will begin to impinge on the area from the north by Wednesday as the aforementioned ridge of high pressure continues to become more suppressed to the south. Low-end wind shear values on the order of 30-40 knots may assist with multicell storm modes that could produce organized outflow wind events during the afternoon hours from Wednesday through Friday. High confidence exists in above-normal temperatures continuing through the entire long-term period. However, increasing coverage of afternoon thunderstorms from mid-week onward will likely limit temperatures somewhat, generally running around 10 degrees above normal instead of the near- record daily heat we will experience this weekend. Overall, generally high confidence exists in the long-term period with excellent agreement in ensemble guidance with regard to synoptic forecast features.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 527 AM MDT Sat Aug 8 2026

Some low clouds have moved into the region this morning across the Nebraska Panhandle bringing MVFR to IFR conditions and even some locally patchy fog. Expect this to continue for a few more hours, but with the sun coming up this bank should begin to dissipate by 15Z. Wind forecast is high confidence for WY terminals as strong W to NW'ly winds expected with speeds 10-20 knots and gusts 25-35 knots, lessening this evening. Wind forecast confidence low for NE terminals as numerous wind shifts are expected. Overall winds not as strong as WY, but speeds 10-15 knots on average expected. A very low chance of a high based shower or storm from KCYS through NE Panhandle, but probability is too low to introduce into TAFs.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Air Quality Alert until noon MDT Monday for WYZ101>119. Red Flag Warning from 11 AM this morning to 9 PM MDT Sunday for WYZ417>433. NE...None.