Rawlins, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

407
FXUS65 KCYS 070520
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1020 PM MST Fri Mar 6 2026

.KEY MESSAGES...

- Snow will taper off from west to east through the afternoon
  and evening hours today. Cold temperatures tonight will lead
  to some re-freezing and black ice concerns into Saturday
  morning.

- Dry, mild, and windy weather will resume Saturday and continue
  through most of the week ahead.

- High Winds are expected to return to the wind prone areas
  Saturday, and continue through at least Monday, if not the
  duration of the week.

- The probability for a significant and widespread wind event on
  Thursday and/or Friday continues to increase.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 200 PM MST Fri Mar 6 2026

A sloppy snow event continues across the area this afternoon as the
upper level low swings by to our south. Wyoming is near the end of
the event, but things are just getting started in portions of the
Nebraska panhandle. A band of potent mid-level frontogenesis has set
up stretching from roughly Kimball to Chadron, with RAP analysis
indicating that we have a narrow region of overrunning warm air
advection on top. This is supporting the development of banded
snowfall along and east of this boundary, which will lead to
additional slushy snow accumulations through the evening hours
across the Nebraska panhandle. The Winter Weather Advisory was
expected to include Box Butte, Morrill, and Cheyenne counties
through midnight tonight, to account for the banded snow moving
eastward. Overall, this snowfall is having trouble sticking since it
started after sunrise and is falling on unusually warm ground
temperatures for early March. Air temperatures are also rather
marginal, generally between about 28 and 34 degrees across the area.
Still, heavy snowfall rates approaching 1-2" per hour over the
Nebraska panhandle this afternoon will result in reduced visibility
and slushy/slipper roads in the area. Further west, mesoanalysis
indicates that some modest 700 to 500-mb frontogenesis has filled
back into the Laramie to Cheyenne corridor which has caused snow
shower intensity to pick up once again. RAP guidance suggests this
should be dissipating by around 3PM or so (but perhaps lingering
over the I-80 summit into the early evening). Once that occurs, we
should taper off to light snow or flurries on the Wyoming side but
an additional slushy inch or so is possible in the meantime. This
afternoon`s snowfall rates are fairly light so snow is having
trouble sticking to anything but existing snow. In addition to the
falling snow, north winds continue to blow through the area,
consistently gusting 30 to 45 mph. Fortunately, this snow is fairly
heavy and wet, so it is not responding to the wind as much as a
lighter snow type might. Still, patchy blowing snow is expected to
continue through the early evening hours. Winds will die down a few
hours after sunset.

With skies progressively clearing tonight and winds trending
lighter, we can expect good radiative cooling tonight, especially in
areas with snow on the ground. Overnight lows were nudged towards
the NBM25th percentile across the board, and closer to the 10th
percentile in our typical cold spots such as Laramie, Saratoga, and
Alliance. With a lot of water and slush sitting around this
afternoon, expect this to freeze solid after sunset, which may lead
to some black ice concerns lasting through Saturday morning.

While much of the region has finally picked up some appreciable
moisture in the last week, our brief reprieve from the
relentless warm, dry, and windy pattern will come to an end this
weekend. The broad trough will move off to the east as the
synoptic weather pattern trends back towards zonal flow across
most of the northern tier of the CONUS. As this transition
occurs, expect rapid warm air advection through the weekend, and
also a return of high winds. The nose of a strong jet streak
aloft will translate over the area tonight, putting us
underneath the right exit region by midday tomorrow. The jet
streak will also support falling surface pressure in the lee of
the northern Rockies, building up the cross-barrier pressure
gradient and the 700-mb height gradient across our area.
Parameters may be supportive for high winds as early as Saturday
morning for the Arlington/Elk Mountain area with marginally
supportive low-level height gradients. In-house guidance shows a
probability for high winds at Arlington of around 60% during
the day Saturday, increasing to 80% after dark. For the Laramie
Range, it may take a little longer to build gradients further
east, but the chance for high winds will be increasing Saturday
night into Sunday morning. The threat for high winds in the wind
prone areas will continue through much of the week ahead, but
more on that can be found in the long term discussion below.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 200 PM MST Fri Mar 6 2026

Sunday morning will have predominantly westerly flow
throughout the day. There looks to be a weak shortwave that will
quickly push through our area and temporary shift the mid level
winds to a northwest direction but the winds do shift back to the
west immediately behind the wave as well. There is no precipitation
associated with this brief shortwave as the downsloping winds off
the Rocky Mountains will create a very stout dry layer at the
surface. At the 700mb level the winds will accelerate to between 60
to 65 knots as the gradient compresses between the two systems
located in Canada and the Southwest Conus/Mexican Border validating
the venturi effect once again. With the 700mb jet accelerating to 65
knots and the consistent depiction of strong subsident flow
(downward mixing) a High wind warning will be in effect from
Saturday evening through Monday evening as of right now. To add
confidence to our high wind warning our in house algorithm does
paint a rather long and consistent 70 to 80 percent probability for
our wind prone areas through that time period as well. Now as these
two systems push off to the east Tuesday into Wednesday, the
intermountain west may see the pressure gradient slightly relax and
cause a mid level jetstream de-acceleration and temporarily suspend
our high winds. However the jet will still maintain a speed of 45 to
50 knots giving us possibly elevated winds but its still a little
uncertain if we will reach possible high wind criteria during this
time as the global omega fields due suggest some maintaining of
subsident flow over our wind prone areas. To further cement the idea
that the gradient will relax enough to prevent high winds is the
expansion of stronger rising motion across our forecast area as the
subsident flow is shown to weaken across our wind prones. Our in
house algorithm does also agree with this meteorological ideology as
it maintains a 60 percent probability for elevated winds instead of
High winds like the previous days. However, given we are still in
westerly flow aloft the Intermountain west is prone to the
development of strong mountain waves from that direction which still
may give us high winds despite the lack of support from the
jetstream itself. A brief ridge does push into the Intermountain
West at this time which does generally help weaken the mountain wave
potential while maintaining our warmer weather. From Thursday
through the weekend, the ridge becomes more broad and less amplified
as it dominates the Southwestern United states behind the earlier
southern low pressure system continuing to push east into the Gulf
region. Meanwhile another system (another one) pushes itself through
the Canadian Providences from the Pacific Northwest. This arrival of
a new system compresses the gradient against the broad ridge
rejuvenating the high winds over the Intermountain west with the
700mb jet ramping up to 70 knots. So another high wind warning may
come into existence later this week as well.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1020 PM MST Fri Mar 6 2026

Minimal aviation weather concerns as VFR conditions will prevail
across all terminals for the duration of this TAF period. Winds
overnight will be generally less than 10 knots. However, winds will
ramp right back due to a strengthening 700mb jet, so expect westerly
gusts in the 25-40 knot range by 19Z Saturday for all sites. At the
tail end of this TAF period, LLWS may become an issue and it was
added into the KCYS TAF. Other sites in the Nebraska Panhandle may
need LLWS added, but it is expected just outside of this
forecast.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning from 5 PM Saturday to 6 PM MST Monday for
     WYZ106-116-117.
     High Wind Warning from 8 AM Saturday to 6 PM MST Monday for
     WYZ110.
NE...None.

&&

$$

SHORT TERM...MN
LONG TERM...MM
AVIATION...RZ