High Wind in Wyoming, April 16, 2026

Area Forecast Discussion
National Weather Service Cheyenne WY
611 AM MDT Thu Apr 16 2026

.KEY MESSAGES...

- Southwest winds will increase today across the area, leading
  to critical fire danger over the High Plains and the potential
  for high winds in portions of Carbon county.

- A very strong cold front will sweep through the area between
  the late afternoon and evening hours today, bringing rapidly
  dropping temperatures and an abrupt wind shift.

- Snow squalls and a flash freeze will be possible this evening,
  primarily in Carbon and Converse counties.

- Widespread snowfall is expected this evening through Friday,
  though exact accumulations remain uncertain.

- Winter-like temperatures in the teens to low 20s are expected
  by Saturday morning, creating a risk for outdoor irrigation
  and sensitive vegetation that has emerged from winter dormancy
  early.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 335 PM MDT Wed Apr 15 2026

Active weather will continue across the area for the next several
days with multiple different hazards anticipated. This will be
driven by a powerful Pacific trough which is already apparent on
GOES satellite imagery moving inland this afternoon. As this feature
dives into the western CONUS tomorrow, it will amplify the
downstream ridge over our area. This will strengthen the southwest
flow aloft beginning tonight and continuing through the day
tomorrow. Median 700-mb wind speeds per the LREF climb to around 45
knots late this evening and remain there through midday Thursday
over much of Carbon County. These values are around the
climatological 99th percentile. The latest probabilities for wind
exceeding high wind criteria from the NBM are in the 50 to 70% range
for much of Carbon county including Rawlins, Elk Mountain,
Arlington, and Muddy Gap. In addition, the wind direction is
favorable for some downslope winds into the Upper North Platte River
Valley. While confidence is lower for that zone, it was enough to
include the Saratoga area in a High Wind Watch. The best window
looks like mid morning through the early afternoon on Thursday, but
the watch covers a longer time period beginning midnight tonight and
continuing until a few hours after the frontal passage on
Thursday to account for a few overnight mountain waves, and
higher than expected wind gusts with the cold front. We will
also need to keep an eye on the Converse County area for a
potential expansion of the high wind threat, but probabilities
are lower there (10-40%).

By mid morning, gusty southwest winds will mix down the surface
across the entire area. Widespread gusts of 30 to 40 mph are
anticipated over the High Plains, which will increase the fire
weather threat. A Red Flag Warning has been issued for all of the
High Plains once again. The increased cloud cover may provide a
failure mode for critical conditions, but confidence was high enough
to upgrade across the board.

Big changes will be on the way as a powerful cold front arrives late
Thursday. Expect this to arrive around 3 to 4PM for our northern and
western zones, including western Carbon and western Converse
counties. The Sidney area will be the last to see the front push
through, with expected timing around 10 to 11PM. As the front
passes through, expect an abrupt wind shift and rapid rise in
surface pressure. Extremely strong frontogenesis will support
precipitation immediately behind the frontal passage. Modest
instability will be present ahead of the front, so we will need
to watch for convective enhancement, particularly due to the
late afternoon timing. The very strong mechanical forcing (as
much as 3 mb per hour pressure rises) and potential for a few
hundred J/kg of CAPE will put snow squalls on the table. While
temperatures will be spring-like ahead of the front, look for a
very rapid drop in temperatures which could add flash freeze
concerns. Rain may flip over to snow very quickly, especially in
Carbon County. Rawlins, for example, should see a high around
the lower 60s Thursday, but may be below freezing by 7 to 8PM,
if not sooner. Travelers across Albany, Carbon, and Converse
counties should be prepared for hazardous, rapidly changing
conditions including low visibility in falling and blowing snow
and icy surfaces especially as the sun goes down. Overnight,
model guidance remains a little split concerning whether some
post-frontal overrunning lift will manage to develop. Forecast
soundings for Rawlins show about 6 hours of a warm nose
developing right in the middle of the dendritic growth zone
between about 9PM and 3AM. A few ensemble members try to bring
low-level dry air in underneath this very promptly, and cut into
precipitation totals. Taken all together, there was enough
confidence in at least some impacts from snow to issue a Winter
Weather Advisory for most of Carbon and Converse counties. These
are the areas where impacts will occur Thursday evening.

The storm system will slowly migrate eastward Thursday night into
Friday morning, spreading cold air and snow with it. While
precipitation should be more or less right behind the front when it
first moves into the area, the surface front will race ahead
overnight. East of a Laramie to Lusk line, forcing for ascent will
not really get going until after midnight, several hours behind the
initial frontal passage. For determining impacts, the exact
start time will be fairly critical. Snow beginning pre-dawn
should easily stick, and create icy and slick conditions for the
Friday morning commute. However, if forcing holds off just a
few hours later until around 9AM or so, after the strong April
sun takes hold, road impacts in particular may be more limited.
Due to this uncertainty, decided to hold off on expanding the
Winter Weather Advisory east of Laramie. The most likely
scenario still includes 1 to 4 inches of snow in Albany, Platte
and Laramie counties, with a dusting to 2 inches further to the
east. In addition to the snow, blustery north winds are expected
with this event. This will lead to chilly wind chill values and
the potential for some blowing snow. Snow might actually be a
little lighter and fluffier than typical for this late in the
season as forecast soundings show a fairly deep, saturated
dendritic growth zone. So, while some melt on contact is
anticipated with the warm ground temperatures, this probably
won't be a typical late April heavy wet snowfall. Ratios are
expected to be around 12:1 to 15:1 in Wyoming, and 8:1 to 12:1
in Nebraska.

The last impact of this system will be the expected cold
temperatures. After a historically warm start to spring, vegetation
has progressed much further out of dormancy than typical for mid
April. This event will not be record challenging cold by any means,
but we will have temperatures far below average. In fact, 700-mb
temperatures will be below the 10th percentile of climatology on
Friday. High temperatures will struggle to get above freezing for
some areas, and all remaining below the lower 40s at the warm end.
As skies clear and winds die down, we should have time for rapid
radiative cooling. Widespread lows in the teens to lower 20s can be
expected by Saturday morning, which will cause issues for outdoor
irrigation systems and sensitive vegetation. Those with such
vulnerabilities to the cold temperatures are encouraged to make
preparations for the cold weather while the warm temperatures last
on Thursday.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 335 PM MDT Wed Apr 15 2026

Saturday...With decent low and mid level gradients and northwest
flow aloft, it looks breezy to windy. 700 mb temperatures near -7
Celsius will yield maximum temperatures in the mid to upper 40s west
of I-25, with upper 40s to mid 50s east of I-25.

Sunday...Ridging aloft moves over western Wyoming with a surface lee
trough developing over our counties. With 700 mb temperatures near 5
Celsius, maximum temperatures will climb into the upper 50s and
lower 60s west of I-25, with mid 60s to lower 70s further east.

Monday...The warming trend will continue as ridging aloft
strengthens and becomes more pronounced over western Wyoming. 700 mb
temperatures near 7 Celsius will produce high temperatures in the
mid 60s to near 80 degrees.

Tuesday...Dry conditions continue as ridging aloft transitions to
eastern Wyoming. Slightly warmer as 700 mb temperatures warm a
degree or two.

Wednesday...As the ridge axis aloft moves to the northern high
plains, our flow aloft will turn southwest with strengthening
surface lee troughing. Temperatures slightly cooler due to more
cloud cover. Slight chances for afternoon showers and a few
thunderstorms due to an increase in low and mid level moisture and
low level convergence.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 557 AM MDT Thu Apr 16 2026

The main aviation concern through the daylight hours will be
wind ahead of an approaching cold front. Southwest gusts of 20
to 30 knots will be seen at most terminals, with KLAR and KRWL
seeing gusts near or above 40 knots. The front will arrive
between 02Z and 05Z and bring a sharp northerly wind shift to
terminals. This will also bring precipitation impacts, and MVFR
to IFR conditions at most terminals after 00Z. This will be most
notable at KRWL which should see a persistent period of snow
before the end of the period.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning from noon today to 8 PM MDT this evening for
     WYZ417>419-430>433.
     Winter Weather Advisory from 6 PM this evening to noon MDT
     Friday for WYZ101.
     Winter Weather Advisory from 6 PM this evening to 3 PM MDT
     Friday for WYZ103>105-109>111-113.
     High Wind Warning until 9 PM MDT this evening for WYZ104-109-
     110-113.
NE...Red Flag Warning from noon today to 8 PM MDT this evening for
     NEZ434>437.

&&

SHORT TERM...MN
LONG TERM...RUBIN
AVIATION...WFO-RIW