Casper, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

278
FXUS65 KRIW 141058
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
358 AM MST Sat Feb 14 2026

.KEY MESSAGES...

- Mainly dry weather continues through Monday.

- Elevated fire weather is likely the next few afternoons,
  especially Sunday, with an emphasis from Rock Springs through
  Casper.

- An approaching weather system will bring snow to western
  Wyoming and strong to high wind east of the Divide from
  Monday night into Tuesday.

&&

.DISCUSSION...
Issued at 1242 AM MST Sat Feb 14 2026

One of the traditions we have in the humble Riverton weather abode,
at least among the older, Gen X crew, is listening to countdowns
of the Top 40 songs of certain weeks from the 70s through the
90s as we compose the forecast. And there are two things from
these that remind me of the weather over the next several days.
The first few days remind me of the classic R&B band that was
popular in the 70s and early 80s, Earth, Wind and Fire. Then we
transfer to Pat Benatar`s early 80s hit "Fire and Ice". Read on
for details.

High pressure will bring mainly dry weather through around Monday
evening, with the exception of some isolated shower activity
across the northwestern mountains. I know the forecast has
showers starting Monday afternoon. However, the models are
almost always too fast with Pacific systems this far out, so we
think it will be dry through at least sunset on Monday. The
main concerns, mentioned above, will be wind and fire weather.
Temperatures will remain well above normal through at least
Monday, in some cases more than 20 degrees above normal. Ridging
will begin to flatten today, and with the southwest flow this
will favor areas from Muddy Gap through Natrona County, we could
see gusts over 30 mph at times this afternoon. This is combined
with dewpoints in the teens. Complicating this is that fuels
are now critical in the lower elevations of Natrona and Johnson
Counties. I did give some thought to fire weather highlights.
Relative humidity should remain above critical levels though,
with only a 1 in 3 chance of humidity below 20 percent in
Natrona County and basically zero chance below 15 percent. Wind
in Johnson County is expected to remain light to moderate and
other locations do not have critical fuels. I am a bit more
concerned about Sunday though as 700 millibar wind climbs to 40
knots, an 100 knot jet moves over Wyoming and a shortwave
brushes by to the north. This will increase wind in Natrona
County with some gusts approaching 40 mph. Relative humidity is
again the limiting factor though, with probabilistic guidance
giving less than a 1 out of 6 chance of humidity below 15
percent. Monday could see elevated fire weather as well, but
slightly less wind and somewhat higher humidity may ease
concerns just a bit.

Starting Monday night we should finally shift to a cooler and wetter
pattern. A Pacific trough and cold front will swing into Wyoming.
This will bring a return of snowy conditions to western Wyoming. It
is a fairly fast mover though, with most of the snow falling in a 12
hour period. As for amounts, many of the western mountains have at
least a 1 in 2 chance of 6 inches or more in a 24 period, but the
chance of 12 inches or more is very small, generally less than 1
out of 10. With mild temperatures at the onset, snow levels
will start fairly high, from 7000 to 8000 feet before falling to
the valley floors by morning. In the valleys, at this time
there is less than a 1 in 10 chance of 3 inches or more although
some accumulation will be likely. There should at least by a
lull after that on Tuesday night.

Shifting to east of the Divide, concerns shift to wind and
fire concerns. Things are setting up nicely at this time for a
decent high wind event. We will have the approaching front and
trough. We will have a tight pressure gradient across the area
Tuesday afternoon, as much as 22 millibars from northeast to
southwest. The 700 millibar winds climb to as high as 65 knots
at 18Z Tuesday. As we head into the probabilistic realm of
ensembles, a good portion of the area, with an emphasis on east
of the Divide, has at least a 1 in 2 chance of wind gusts past
55 mph on Tuesday. Some of the wind prone areas near Casper have
at least a 1 in 2 chance of wind gusts over 70 mph. This,
combined with humidity remaining low, could also bring
widespread elevated fire weather east of the Divide. The chance
of critical fire weather looks low though, as slightly cooler
temperatures should keep humidity above critical levels. As for
precipitation, the chance looks low with the strong
southwesterly downsloping flow. There is a small chance of
showers post-frontal, but any amounts should be very small.

Another system may then approach for the middle and latter part of
the week. There is more model spread on this and it being at least 5
days out, I won`t try to pin down details. However, this could
possibly, emphasis on possibly, be the best chance for some
measurable precipitation east of the Divide. The latest model
runs are indicating some lee cyclogenesis over Colorado, and
this could turn mid and low level flow more easterly, bringing
in some better moisture. There are also a few models showing a
700 millibar low over Central Wyoming, all things we need for
precipitation east of the Divide. Again, it is still several
days out and guidance can flip flop at this distance. However,
at this point, this may be the best chance for measurable
precipitation east of the Divide that we have had in a while. As
for temperatures, we look to finally have a period of near to
below normal ones with broad troughing over the western United
States. However, with the flow largely from the Pacific, no
frigidly cold air is expected.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 340 AM MST Sat Feb 14 2026

VFR conditions are expected to prevail at terminals through the
period. FEW-SCT FL150-250 clouds will continue to stream from
west to east through the day. Lower MVFR ceilings will linger
over Yellowstone through the morning. Lee-enhanced clouds will
increase to BKN-OVC over the central basins after 06Z. KCOD and
KCPR will see gusts between 18 and 25kt; remaining terminals
will generally see gusts remaining under 20 knots.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on icing and turbulence forecasts.

&&

.FIRE WEATHER...
Issued at 1242 AM MST Sat Feb 14 2026

Elevated fire weather will be possible over the next few days.
The main area of concern today is from eastern Sweetwater County
through Natrona County, where wind gusts over 25 mph and
relative humidity to 20 percent will be possible. Sunday will be
a greater concern with stronger wind and somewhat warmer
temperatures. Concern may ease a bit Monday. An approaching cold
front may bring more widespread elevated fire weather on
Tuesday with stronger winds expected. At this time, with
relative humidity expected to remain above 15 percent for the
most part, critical fire weather is not expected.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Hattings
AVIATION...LaVoie/Myers
FIRE WEATHER...Hattings