395
FXUS65 KCYS 061134
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
434 AM MST Fri Mar 6 2026

.KEY MESSAGES...

- A Winter Storm Warning and multiple Winter Weather Advisories
  remain in effect through tonight. 2 to 5 inches of snow
  possible in the Advisory areas with locally higher amounts
  possible under banded precipitation.

- Confidence is low to medium elsewhere due to uncertainty in
  the potential for banded snowfall during the day on Friday.

- A High Wind Watch has been issue from 11 AM Saturday through
  11 AM Monday for the typical wind prone areas of southeast
  Wyoming. Gusts up to 60mph will be possible.

- Warmer and drier conditions will return Saturday onward with several
  periods of high winds expected Sunday into much of next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 241 AM MST Fri Mar 6 2026

Snow is ongoing across many locations early this morning. As of 12
AM, Cheyenne has received 0.2 inches of snow, with snow continuing
over the next several hours. Current Mid-Level Water Vapor Satellite
shows moisture streaming into the region with the low moving south
across eastern Utah as of 2 AM this morning. This low will begin to
push eastward as the upper-level trough slowly drags eastward. The
building upper-level ridge over the Pacific Ocean just off the coast
of California is visible on WV satellite tonight and is expected to
amplify and lean towards the northeast due to strong anticyclonic
vorticity advection on the backside of the upper-level trough. This
results in the upper-level trough becoming positively tilted late
this morning and into the afternoon hours. As the ridge continues to
strengthen and the upper-level trough tilts positively, the base of
the trough looks to become pinched off to the southwest of the Four
Corners Region, leading to a closed low circling over northwestern
portions of Mexico and far southern California. Back to the CWA, the
upper-level flow becomes northerly late today into the overnight
hours, leading to an end in precipitation. However, before this
occurs, the 700mb looks to develop over the east central Colorado by
the late morning and advect northeastward across eastern Colorado
into central Nebraska. This low will later be picked up by the
northern branch of the now separate upper-level trough, leading to a
quick northeastward ejections starting in the early afternoon hours
today. The surface low will be positioned much further south and
east than typically preferred for snowfall across the CWA, however,
with the upper-level trough stalling as it pinches off the southern
half, the region will remain just downstream of the 700mb jet where
constant synoptic ascent is expected. As the associated cold front
pushes through the region, it will prolong the synoptic ascent
across the region leading to precipitation not ending until late
tonight despite the 700mb trough being off to the east. The 700mb
trough will advect in colder air throughout the morning, with a
reinforcing shot of cold air following the cold front passage. 700mb
temperatures are expected to remain in the -10 to -8C range all day,
so all precipitation today should be snow, especially across
southeast Wyoming.

Close attention is currently being paid to where a band of very
strong frontogenesis develops this morning. Current model runs
suggest this strong frontogenesis band develop from about the
Vedauwoo northeast through the Dawes County in the northern
Panhandle. This band is expected to move eastward with the departing
700mb low and incoming cold front, resulting in an eastward shift in
the best ascent throughout the morning hours. Current radar data is
mostly in line with the current model placement of the strong
frontogenesis band. Snow is ongoing from about Vedauwoo northeastward
through at least Goshen County, with the heaviest band currently
running along I-25 from Cheyenne to Wheatland. Snow rates are
looking quite good as of 230AM this morning in Cheyenne,potentially
around 2 inches an hour, with the heavy snow. At this time, radar
seems to be showing the heavy band starting to stall a bit across
the I-25 corridor, though it is not obvious enough at this time to
say yes it is stalling. This band is may stall a bit due to the
upper-level flow becoming disturbed before the northern portion of
the trough detaches from the southern portion. Even if this band
does not stall, 08Z HRRR data suggests that the snow will continue
to fill in along and east of the Laramie Range as more snow moves
off the Colorado Rockies into southeast Wyoming. The largest
uncertainty at this time is whether or not another band of heavy
snow will set up across the Panhandle and if it does, where exactly
it will set up. Did increase snow totals slightly across the
Nebraska Panhandle, but still have below advisory criteria,
especially since confidence remains lower on banding. Did not change
any of the Winter Headlines with this forecast package. Will
continue to monitor for a significant band of snow setting up across
the Panhandle, which could significantly increase snow totals.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 241 AM MST Fri Mar 6 2026

A High Wind Watch has been issued for the wind prone areas of
southeast Wyoming from 18Z Saturday through 18Z Monday. Other than
this, the previous discussion remains valid. Please see previous
discussion below...

Saturday evening we start to transition from a northwesterly to a
truly zonal flow over the Intermountain west. This is in part due to
the low pressure system migrating through the US southwest/northern
Mexico region of North America at the same time an upper level wave
pushes through the Canadian Providences. This forces the jetstream
to accelerate over the Rocky mountains as the pressure gradient
compresses resulting in high winds for our wind prones areas
Saturday night into early Sunday morning. Omega values start to max
out Monday morning with strong subsident flow presenting stronger
certainty in high winds for Monday as opposed to the juggling
between the strong to maxed out subsident flow values for Sunday as
the 700mb jet slowly intensifies. The 12z run of the global models
has the 700mb jet slowly gaining intensity throughout the day Sunday
reaching speeds between 50 to 60 knots by Sunday afternoon to the
early evening time frame. By Monday the system moving across the
Canadian Providences takes a little more southern route tightening
the gradient even more around Monday evening. The 700mb jet model
response to this deviation is sporadic blips of intensity between 65
and 70 knots while in westerly flow. Given the Mountain wave like
set up depicted in the omega fields of the global models. It would
surprise me to see gusts up to 80 mph in the wind prones during the
periods of 65+ knot intensities. To further confirm my forecast of
high winds, our in house algorithm gives probabilities between 60 to
80 percent for high winds at Arlington starting Saturday evening
through Monday afternoon with the high probabilities starting Sunday
evening for Bordeaux. The models keep us in straight westerly flow
with intermittent intensities between 55 and 60 knots for the
remainder of the work week. It will be something to keep track of,
but we could see possible elevated to high winds throughout the work
week as well if these models trends continue.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 431 AM MST Fri Mar 6 2026

Challenging forecast this morning as snow bands slowly move
across the region. Most terminals are expected to see impacts
from snow bands, likely leading to IFR or LIFR conditions
throughout the day. KBFF, KCDR, and KAIA will likely see a rain
to snow transition this morning, while KSNY is expected to
receive enough cold air to lead to snow only. Conditions are not
expected to improve much until this evening when snow tapers off
west to east and skies begin to clear. Breezy conditions will
likely lead to blowing snow, combined with falling snow,
throughout the day, but especially in the afternoon hours after
snow has had more time to accumulate.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 6 PM MST this evening for WYZ104-
     106-109-110-113-115-117-118.
     Winter Weather Advisory until midnight MST tonight for WYZ103-
     112-114.
     High Wind Watch from Saturday morning through Monday morning
     for WYZ106-110-116-117.
     Winter Storm Warning until midnight MST tonight for WYZ116.
NE...Winter Weather Advisory until 6 PM MST this evening for NEZ002-
     095.

&&

$$

SHORT TERM...AM
LONG TERM...MM/AM
AVIATION...AM