Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

640
FXUS65 KCYS 050550
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1050 PM MST Wed Mar 4 2026

.KEY MESSAGES...

- Another round of accumulating snow is expected Thursday
  evening into Friday night. Considerable uncertainty remains
  regarding forecast snow totals.

- Two scenarios for the evolution of the storm system remain
  possible, which would lead to significantly different
  outcomes for our area.

- Gusty winds are expected Friday in the wake of a cold front.
  This will lead to blowing snow concerns in areas receiving
  snow Thursday night and Friday.

- The pattern will shift to mostly dry and above normal
  temperatures after Saturday and persist through the start of
  next week with high winds possible during this time as well.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 400 PM MST Wed Mar 4 2026

The primary forecast challenge today is the potential for snow
accumulation on Thursday night into Friday. First, we have another
warm day to get through before winter returns. Currently, we have
mainly clear skies in place over the area with mild temperatures in
place once again. Winds are pleasantly light for most areas aside
from a few modest breezes. Cloud cover associated with the next
storm system is already apparent on GOES satellite imagery moving
into the western CONUS this afternoon. A north to south band of mid
to high level cloud cover is out ahead of the primary trough axis.
This will push in late this evening and lead to a cloudy start to
Thursday morning especially along and east of the Laramie Range.
Expect a window of sunnier skies in the late morning to early
afternoon hours as the dry-slot moves overhead, before cloud cover
increases again in the late afternoon hours Thursday. Temperatures
will be quite warm once again Thursday, mainly east of the Laramie
Range, with southwest flow aloft supporting strong warm air
advection ahead of the approach upper level low. 700-mb temperatures
in the 0 to +3C range over the High Plains, supporting widespread
60s and maybe a chance at 70 degrees in some lower elevation areas.

Thursday evening, attention will shift to the potential for snow. We
will start off here with an overview and then get into the details
and scenarios for snow accumulation outcomes. We may see a few
elevated showers developing late Thursday afternoon and evening, but
these will be on top of very dry boundary layers, so anything
reaching the ground is fairly unlikely. The surface cold front is
expected to move through the area in two phases. During the day on
Thursday, an elongated surface trough will develop just east of the
I-25 corridor. So, while an initial push of cool air will move in
Thursday morning, this is expected to stall west of I-25 during
most of the day. By the evening hours, the secondary surface low
over northeast Wyoming will begin to cede to a stronger developing
surface cyclone in northeast Colorado. As this happens, expect a
second push of cooler air to sweep through the High Plains, with
gusty north to northwest winds moving in behind. This will make for
a dynamic evening as strong frontogenesis sweeps through the area
moving into the developing cyclone. In addition, we will have steep
lapse rates and some modest instability present, possibly locally
enhancing precipitation rates. Initially, snow levels will be around
7500 ft, so precipitation may be rain to begin with. However, expect
this to change quickly over to snow at least for areas above about
6000 ft. Cold air advection overnight into Friday morning will
continue to drop snow levels, and we should be seeing mainly snow by
daybreak. Gusty north winds will fill in over most of the area by
Friday morning as well, which will at least be producing some colder
wind chills, and possibly leading to areas of blowing and drifting
snow depending on how much falls. On that subject, let`s get into
the details on a pretty uncertain forecast below.

Models have diverged into two distinct camps today, each leading to
wildly different outcomes for our area. The deterministic GFS and
deterministic ECMWF are fairly representative for each camp. The
first scenario represented by the GFS depicts a stronger upper level
low positioned slightly further north, while the second scenario
represented by the ECMWF shows a weaker upper level low positioned
slightly further south. The overall synoptic set up will be a split
trough moving across the area, with a parent trough well to our
north over the US/Canada border, and a second upper level low moving
across the central Rockies. The key differences are in the strength
of this second upper level low. The more aggressive GFS scenario
deepens this low enough to close it off and distinctly separate the
system from the parent trough. This allows easterly flow in the 700
to 500-mb layer to develop over our area by Friday morning,
funneling in good moisture and very strong isentropic lift into our
area. A TROWAL backing into the area will support strong lift
through much of the day Friday and widespread accumulating snowfall
over the High Plains. In the ECMWF scenario, the secondary upper
level low is slightly weaker, and thus does not close off from the
parent trough. Remaining as an open wave, easterly flow is prevented
with deeper moisture deflected off to the north and east towards the
parent trough. Without the easterly flow and moisture tap, the
window for precipitation is much shorter, likely ending Friday
midday  or so. Precipitation rates would also be lighter and
primarily driven by frontogenesis, since the strong positive theta-e
advection and isentropic lift would be lacking. It is difficult to
favor one scenario over the other at this time. Nearly all GEFS
members are very much in line with the deterministic GFS, whereas
nearly all ECMWF ensemble members are close to their deterministic
run. The Canadian ensemble suite is a little closer to the ECMWF
camp, while AI ensemble systems generally lie somewhere in between.
This event is near the tail end of the usefulness of high resolution
models still, but those are equally divergent, with the HRRR showing
a solution roughly in between the two scenarios, and the 3km NAM as
an extreme outlier with little to no precipitation for the majority
of the area.

Taken all together, the divergence between model scenarios leads to
a fairly low confidence forecast today. The official forecast
generally splits the difference between the two most likely
scenarios, but we have a huge spread between the 10th and 90th
percentiles. At this time, the highest confidence in some snow
impacts is generally inside an Elk Mountain to Wheatland to Cheyenne
triangle. In this area, the most likely snowfall range is around 3
to 6 inches, but the high end scenario could be as much as 8 to 10
inches. Northerly surface winds are good for accumulating snowfall
in the Elk Mountain to Laramie corridor, including the city of
Laramie, then extending eastward to just north of Cheyenne up
towards Chugwater. The Pine Ridge area from Douglas towards Chadron
can also do well in northerly flow, but the western part of that
area may be on the edge of the moisture, while the eastern part may
have issues with precipitation type and snow melting upon reaching
the ground due to warm temperatures. For today`s update, decided to
focus on headlines along and west of the Laramie range, and will
leave the I-25 corridor and points east to later shifts. The highest
probability for warning criteria snow amounts is in the southern
Laramie Range where a Winter Storm Watch has been issued. In
adjacent areas including the I-80 corridor from Elk Mountain to
Laramie and the central Laramie Range, the probability for warning
criteria amounts is about 30 to 40% at this time, which is a little
lower than we would like to see for a watch. Opted to issue a Winter
Weather Advisory for this area, but there is a notable chance this
may need to be upgraded to a Winter Storm Warning if the higher end
scenario becomes favored. A Winter Weather Advisory was also issued
for much of Carbon County, but this will be a more marginal advisory
compared to areas further east. This may also need to be expanded
into the Saratoga and Baggs areas, but did not have the confidence
to do so at this time. We will also need to expand headlines
eastward, but the start time will be a little later there so will
wait a bit longer for confidence to improve.

The different scenarios have also differ in the end time of
precipitation, but we should be done by around midnight Friday
night even in the high end scenario. Warm air advection will
return for the weekend behind this storm system.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 400 PM MST Wed Mar 4 2026

At the start of the long term, a benign weather pattern will settle
in across the region as a system that impacted our CWA the day
prior exits off to the east. As we progress through Monday, we dry
out and remain dry as precipitation chances are minimal with the
upper-level pattern becoming zonal. Then, a pattern change is
possible Tuesday as a shortwave drops south, increasing
precipitation chances and leading to cooler temperatures, more on
that later. As of now, most of the precipitation associated with
this system should remain all rain at lower elevations and snow in
the higher terrain. There maybe a short window of the rain
transitioning to snow Tuesday night, but at this time there should be
minimal to no snow accumulations at the lower elevations. Now, lets
take a look at temperatures, with a fresh blanket of snow across the
CWA, expect slightly cooler temperatures to continue into Saturday.
Thereafter, a warming trend will ensue Sunday as 700mb temps
increase into the 2 to 4 degree C range. These temperatures will
remain in place through Monday, then with a front diving south
Tuesday, cooler temperatures will once again make a return. So, we
don`t live at 700mb, what does this all mean at the surface? Well,
expect highs to climb into the mid 30s west of I-25 and 40s to low
50s east of the corridor on Saturday. Temperatures will warm Sunday
into Monday as highs soar into the upper 40s to low 50s west of I-25
and low to upper 60s to the east, warmest across the Nebraska
Panhandle. By Tuesday, a cooling trend will round out the long term
period.

Switching to winds, expect windier conditions to make a return to
our wind prones across southeast Wyoming Sunday through Wednesday. A
700mb jet will dive south, increasing mid-level winds to near 65
knots Sunday afternoon/evening. These winds will mix down to the
surface as sinking air aloft sets up, negative Omega (GFS). There
will be some variance in strength through Wednesday, but expect the
windy conditions to continue from Sunday. All this coupled with our
in-house guidance, there is a 80% chance of high winds along I-80
near Arlington late Saturday though Sunday night and along I-25 at
Bordeaux. High wind probabilities decrease through the remainder of
the forecast period. As of now, in-house guidance has probabilities
of high winds in Cheyenne generally less than 20% for the
aforementioned duration.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1050 PM MST Wed Mar 4 2026

Quiet weather expected over the next 18 to 24 hours with low
Aviation impacts. The next Pacific storm system and associated cold
front will move into Wyoming late Thursday afternoon and evening,
with winds shifting more out of the north or northwest.

HAZARDS/WEATHER TRENDS: VFR conditions will prevail over the next 24
hours. The leading edge of the colder air will move into KRWL, KLAR,
and KCYS after 19z, with winds shifting into the northwest. Gusts
between 20 to 30 knots possible for mainly KRWL and KCYS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory from 8 PM Thursday to midnight MST
     Friday night for WYZ103-106-110-112-114-115.
     Winter Weather Advisory from 8 PM Thursday to 6 PM MST Friday
     for WYZ104-109.
     Winter Storm Watch from Thursday evening through Friday
     evening for WYZ116-117.
NE...None.

&&

$$

SHORT TERM...MN
LONG TERM...RZ
AVIATION...TJT