Red Flag Warning 28, NWS Cheyenne, WY

793 
WWUS85 KCYS 280134
RFWCYS

URGENT - FIRE WEATHER MESSAGE
National Weather Service Cheyenne WY
734 PM MDT Sat Jun 27 2026

WYZ417>419-430>433-280245-
/O.EXP.KCYS.FW.W.0028.000000T0000Z-260628T0200Z/
Niobrara/Lower Elevations of Converse/Thunder Basin National
Grassland-
Middle North Platte River Basin/Niobrara and Converse High Plains-
North Laramie Range and Adjacent High Plains-
Laramie Foothills and High Plains-Laramie East High Plains-
Bordeaux/Chugwater/Wheatland-Goshen/Middle-
Lower North Platte River Basin-
734 PM MDT Sat Jun 27 2026

...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR GUSTY
WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 417, 418, 419, 430,
431, 432, AND 433...

As temperatures go down this evening, RH values are expected to 
continue increasing. Therefore the Red Flag Warning will be 
allowed to expire.

$$

Area Forecast Discussion
National Weather Service Cheyenne WY
550 AM MDT Sat Jun 27 2026

.KEY MESSAGES...

- Warming temperatures, falling humidity, and increasing winds
  will increase fire weather concerns this weekend into early
  next week.

- Marginal Risk of strong to severe thunderstorms this weekend
  for the western Nebraska Panhandle. Hail and strong gusty
  winds are possible.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 245 AM MDT Sat Jun 27 2026

Showers and thunderstorm continue early this morning over the
northern Nebraska Panhandle as the low level jet increases over
the Great Plains. Low to midlevel meso-analysis showing MUCAPE
of 1500 j/kg in and around Chadron Nebraska. Was a bit concerned
about the South Fork Burn scar west of Chadron and Crawford as
a strong thunderstorm moved near the area between 1 to 2 AM.
Radar estimates in the core of the cell were nearing 1 inch of
rain/hour. Thankfully, the cell redeveloped further south and
east...sparing most of the area. Will continue to monitor
trends and river levels this morning, but not anticipating any
flash flood products at this time as the westward extent of the
line enters north central Sioux county at this hour.

Although drier air will continue moving into the region today,
it is forecast to advect into the area much slower than
previously thought a few days ago. Currently, dewpoints are in
the upper 50s and low 60s as far west as Cheyenne, Wheatland,
and Douglas under southeast upslope winds. Even some low clouds
and patchy fog have been observed early this morning. Fire
weather concerns are expected to be delayed a day or two over
most of eastern Wyoming and western Nebraska with dewpoints
remaining in the low to mid 60s across the Panhandle this
morning. In addition, flash flooding was more widespread than
expected yesterday with 1 to 2 inches of rain observed in many
locations...especially in and around Scottsbluff and Bridgeport
Nebraska. A dryline is expected to form this afternoon and
slowly drift eastward into far eastern Wyoming and western
Nebraska. This will likely result in enough convergence and
forcing to initiate isolated to widely scattered thunderstorms
over western Nebraska (depending on the dryline location). Added
15 to 25 percent POP and Prob thunder east of a Lusk to Kimball
line. Dry air is currently over Carbon county and is going to
take its time moving into the I-25 corridor, but do expected
this to happen sometime around noon. Most model guidance shows
dewpoints remaining in the 50s for portions of the Nebraska
Panhandle well into the late afternoon hours. Although high res
guidance hasn't caught on to the convection initiation, expect
storms to develop somewhere near the Nebraska border and move
northeast. With enough shear and CAPE, expect a few to become
strong to marginally severe with strong gusty winds the primary
concern, and hail and heavy rainfall secondary concerns.

Models show the drier airmass moving into western Nebraska for
Sunday as a Pacific upper level trough tracks east of the Great
Basin region and into Wyoming and Montana. In fact, some late
season snow is expected over Montana from this system. For
southeast Wyoming, mainly dry with warm temperatures ahead of
the cold front. Highs in the 80s to low 90s are expected with
70s west of I-25 as the cold front begins to push into central
Wyoming. Once this front begins to move east later on Sunday, a
surface low is expected to form across the plains and rapidly
move northeast. Additional moisture advection is expected with
return flow off the Great Plains as winds shift into the south
or southeast. Models are indicating another round of thunderstorms
later Sunday and possibly Sunday night as a rare (for this time
of the year) 100kt jet max lifts northeast into the eastern
plains. Plenty of upper level diffluence is noted with this
feature along with surface convergence near the frontal
boundary. Increased POP Sunday evening and Sunday night along
and east of the I-25 corridor. Some strong to marginally severe
thunderstorms are possible due to pretty good forcing for late
June.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 121 PM MDT Fri Jun 26 2026

The persistent troughing that has been glued to the northwest the
better part of the weekend will still be with us to start off the
long-term. A strong shortwave on the southern end of this trough
will swing by Sunday night into Monday morning with a cold front. We
will start off Monday on the backside of the front with winds
shifting from the northwest and drier continental air advecting in.
High temperatures will be slightly cooler than Sunday's, reaching
the upper 70s west and 80s east. Skies should stay mostly clear and
winds breezy up to 45-50 mph in some portions of the area. Some high
wind conditions may show up along the Laramie Range near the
Wheatland area. Most will see gust up to 30 mph. Despite the
rainfall we have received the last few days, fuels remain dry in the
Nebraska and most eastern Wyoming firezones. The anticipated
conditions do incite some concerns in elevated wildland fire
possibilities that basically stick around the rest of the long-term
period.

Tuesday sees much the same as Monday. Winds relax slightly as the
shortwave moves off to the northeast and a ridge axis noses in. This
will also mark the start of a warming trend through at least Friday,
if not longer. Another shortwave associated with the larger
troughing will swing by Tuesday. At the surface enough return flow
out of the southeast may allow a few storms to develop as the
shortwave moves overhead, primarily for the eastern areas. Past
Tuesday temperatures continue to increase each day with a slight
chance of afternoon thunderstorms. Bulk windshear stays elevated
through this period, so I wouldn't discount some risk of severe
thunderstorms. Unfortunately after Friday global ensemble models are
hinting at a large upper level high pressure system developing and
persisting. If this is indeed the reality of the very long term, we
could be in for a long period of hot and dry weather.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 550 AM MDT Sat Jun 27 2026

A drier airmass will move into southeast Wyoming and parts of far
western Nebraska today. Winds are also expected to increase out of
the southwest with gusts of 40 to 45 knots possible. Widely scattered
thunderstorms possible for KCDR, KAIA, and KSNY.

HAZARDS/WEATHER TRENDS: Winds will quickly increase at KRWL and KLAR
over the next few hours with gusts as high as 45 knots possible late
this morning through the afternoon. KCYS will be breezy with gusts
of 35 knots by this afternoon. Further east, added PROB30 for widely
scattered thunderstorms after 22z. Gusty winds and brief heavy
rain may be associated with these thunderstorms.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

SHORT TERM...TJT
LONG TERM...RV
AVIATION...TJT