829 
FXUS65 KCYS 030910
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
310 AM MDT Fri Oct 3 2025

.KEY MESSAGES...

- Elevated to near-critical fire weather conditions expected
  today across Converse and Niobrara Counties, as well as the
  northern Panhandle.

- Widespread precipitation expected Saturday as a potent
  shortwave moves through the region.

- Strong winds will be possible in the typical windy areas on
  Sunday. Gusts approaching 50 to 55 mph may be possible.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 310 AM MDT Fri Oct 3 2025

Mostly clear tonight across the region with only a few mid-level 
clouds moving across northern portions of the CWA and the higher 
elevation of southeast Wyoming. Temperatures have remain fairly 
steady in the mid-40s to mid-50s across southeast Wyoming and upper-
50s to low-60s in the Nebraska Panhandle. Gusty, downsloping winds 
are ongoing at Chadron, leading to an anomalously warm temperature 
of 66F, as compared to the rest of the CWA. Gusty winds near Chadron 
will begin to subside late morning into the early afternoon hours as 
the low-level jet moves out of the region.

An fairly active period is expected today through Sunday, though not 
in the typical "active pattern" we usually see. Everything from fire 
weather conditions to near high winds to rainfall and storms to 
mountain snow is expected. Today will be relatively "quiet" across 
the region as an upper-level ridge slowly pushes off to the east as 
a strong, upper-level trough advects eastward. Several 500mb 
vorticity lobes will eject out ahead of the incoming upper-level 
trough, though dry, southwesterly winds across western portions of 
the region will keep precipitation chances relatively low through 
the morning and afternoon hours. However, the upper-level trough 
begins to impact the region in the evening hours. Will the trough 
approaching, ample synoptic lift will be present, combined with 
southwesterly flow throughout much of the atmosphere. This 
southwesterly flow in western portions of the CWA will lead to 
strong upslope flow. With increasing moisture in the middle and 
upper-atmosphere, precipitation chances begin to increase by around 
00Z this evening and throughout much of the overnight hours. 
Precipitation chances range between about 15 and 30%, with values 
steadily increase to around 40 to 50% by 12Z tomorrow. Precipitation 
will be initially confined to the higher elevations where the best 
lift is, but showers will begin to spread northeastward as the upper-
level trough continues to push into the area and support synoptic 
lift across more of the CWA. In addition to the precipitation 
chances associated with the southwesterly flow, winds will also 
remain quite elevated across Carbon County and spilling into 
portions of Albany County throughout the day today. Gusts upwards of 
35mph will be possible, with locally higher gusts possible as well. 
The final concern today will be elevated fire weather conditions 
across Converse and Niobrara counties, as well as portions of the 
northern Panhandle. At this time, relative humidity values look to 
drop into the 14 to 17% range this afternoon, but gusty winds will 
remain more confined to southeast Wyoming, limiting fire weather 
concerns in the northern Panhandle. Brief Red Flag conditions may be 
observed this afternoon in Converse and Niobrara counties, but three 
consecutive hours of Red Flag conditions are not expected and will 
not be overly widespread.

Active weather continues on Saturday into early Sunday morning as 
the upper-level trough continues its eastward advance. Models are 
suggesting that a potent shortwave will eject through the large-
scale trough Saturday evening into early Sunday morning. 500mb 
vorticity supports this as strong cyclonic vorticity advection 
separates from the base of the primary trough, leading to the potent 
shortwave developing and pushing through the region. The primary 
trough is not expected to move through the region until early to mid-
week next week. The shortwave followed by synoptic lift associated 
with the main trough will lead to a two round approach to 
precipitation Saturday and Sunday. The first round begins Saturday 
with the shortwave pushing through. The second round arrives later, 
Sunday into Monday with the approaching main trough. Focusing on 
round one, looking at the surface, a low pressure system is expected 
to develop over northern Colorado, associated with the deepening 
shortwave trough in the upper-levels. This surface low will quickly 
propagates northeastward, putting the CWA in the northern and 
northwestern portion of the low throughout its entire track. As a 
result, widespread precipitation is expected. The cold front 
associated with the system will be strong, leading to Sunday's highs 
being 10 to 15F lower than Saturday. The timing of the cold front, 
however, is not favorable for much snow across the region. Much of 
the CWA will remain in the warm sector of the system, leading to 
primarily rain across the region. The Snowies and Sierras will be 
the first to cool off enough to get some snow. The mountains could 
see an inch or two from the system, but are mostly expecting rain. 
The coolest air arrives around midnight Saturday, when much of the 
heaviest precipitation has moved out of the region. However, with a 
strong cold front like this in the transition season, some flurries 
will be possible, mainly in the Laramie Valley, where temperatures 
begin to cool before the bulk of the precipitation moves out. 
Overall, this system will be very wet, with minimal snow outside of 
the highest elevations.

Looking slightly ahead, strong winds will be possible early Sunday 
morning into the day Sunday as the 700mb trough pushes through an 
the jet increases to around 45 to 50kts across the Laramie Range and 
Arlington. GFS omega fields are favorable for strong downsloping in 
these region and in-house guidance suggests about a 60% probability 
for a short period of high winds at Arlington. This set up will 
continued to be monitored, but the first High Wind Warning of the 
season may be needed soon.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 206 PM MDT Thu Oct 2 2025

At the start of the long term, an upper-level trough is across the 
western CONUS which is being anchored by a stout upper-level low 
centered over Utah. This trough will slide east across our CWA 
Saturday, which will be the start of some changes for the region. 
Lets first look at Saturday, a shortwave will ride up the trough 
into our CWA as a cold front sweeps across the area. This will 
result in a wet Saturday afternoon and evening with widespread 
showers and chances of isolated thunderstorms. In addition to the 
precipitation, a breezy day is in store as a tight pressure gradient 
sets up over the CWA along with cooling temperatures. However, highs 
for Saturday will still climb into the 60s west of I-25 and 70s to 
low 80s east of the corridor ahead of the cold front. By Sunday, the 
upper-level trough will eject to the northeast bringing a return of 
southwest flow which wont have much of an effect on surface 
temperatures as the cold will be locked in, more on that later. As 
the trough moves out of the region, additional upper-level 
disturbance will slide across the CWA, keeping chances of shower 
activity through the day on Sunday. Surface temps, well, 700 MB 
temperatures will hover around -2 degrees Celsius across our western 
zones and 0 degrees over eastern Wyoming and the Nebraska Panhandle. 
With that being said, expect a chilly day with highs topping out in 
the low 50s west of I-25 and upper 50s to lower 60s east of I-25. 
What about lows over the weekend, well, lows will dip down into the 
lower to mid 30s across western portions of the CWA and low to mid 
40s for eastern portions, slightly cooler for Sunday night. If you 
are wondering, there will be snow chances primarily above 9K feet 
across the Snowy Range and Sierra Madres with accumulations of up to 
an inch. Heading into the work week, there are some model 
differences, but consensus has a weak ridge building back into our 
CWA through Tuesday with another trough rolling through Wednesday 
and Thursday. Precipitation chances, at this time, appear to be 
minimal while we will see gradual warming trend. Temperatures early 
next week will remain cool with highs struggling to reach the mid 
50s to mid 60s, but by the end of the long term we expect highs to 
climb back into the low 60s to low 70s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1056 PM MDT Thu Oct 2 2025

VFR conditions expected for the forecast period. Intermittent
gusty winds are possible in the Nebraska panhandle through early
morning with a nocturnal low-level jet. Be prepared for LLWS
when the winds at the surface are light. 

Southwest winds will spread into KRWL and KLAR during the day
Friday, with gusts of 25 to 35 knots expected. A few showers
and/or thunderstorms may creep into the vicinity of KRWL late in
the TAF period. We will also need to watch for another low-level
jet Friday night in the Nebraska panhandle.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...AM
LONG TERM...RZ
AVIATION...MN