139
FXUS65 KCYS 190535
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1135 PM MDT Wed Jun 18 2025

.KEY MESSAGES...

- A warming and drying trend will take over Wednesday through
  Saturday. Near record high temperatures are possible on Friday
  and Saturday.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 303 PM MDT Wed Jun 18 2025

An upper level ridge will be the dominant pattern in the short term
period. The Intermountain West will be dry over the next couple
days. The upper level ridge will advect in warm dry air from the
Southwest Desert of the United States. This warm air would raise
temps into the 90`s and possibly into the 100`s but those values
would be reached in the Panhandle. For the Southeast Wyoming area
temperatures will reach into the 80`s and 90`s over the next couple
days. Confidence is high in these temperatures due to NAEFS progging
700mb temps into the 99th percentile. Models also show consensus
with this ideal as 700mb temperatures are forecasted to run between
18C to 20C in some areas. In combination with these warm temperature
its expected to be dry precipitation wise. Westerly flow aloft will
form a dry layer near the surface allowing dewpoints to drop into
the high twenties and 30`s dropping RH values into the teens. Fire
weather concerns are minimal due to our green up and recent
rainfall despite the warm temperatures and dry conditions. Friday,
An upper level trough with produce a surface low that will compress
the pressure gradient as it travels through the Intermountain West.
Friday will be pretty gusty in the afternoon and evening. Sustained
winds look to be in the 30`s and wind gusts up into the 50`s. It`s a
little uncertain if we will reach high wind criteria because there
some disagreement between the models with determining the velocity
of the low level jet that develops Thursday night. With the ridge
increasing subsident flow the strength of the low level jet will
determine on how strong the gusts will be. The Craig to Casper
gradient maxes out into the 50`s on Friday and Saturday which
strengthens the argument for those stronger winds.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 303 PM MDT Wed Jun 18 2025

Hot conditions will continue through Saturday before a trough
approaches from the west and begins to reign in the temperatures
slightly on Sunday. For highs on Saturday, the ECMWF continues to
push 700mb temps of 20C. This will reflect at the surface as highs
in the mid 90s (80s west of Laramie). Despite these high air temps,
a dry low-level with keep apparent temps in the upper 80s, with a
few low 90s in western Nebraska late Saturday afternoon. An upper-
level jet will lead to some gusty winds on Saturday, particularly
out west where surface gusts could approach 40kts. Dry, hot, and
windy conditions will lead to widespread fire weather concerns on
Saturday.

By Sunday, the upper-level ridge will be on its way out, but it will
still manage to get into the upper 80s in the Nebraska panhandle. It
will continue to be precip free until the trough moves in later in
the day. This trough will bring much cooler temperatures and a
chance for more rain, with the highest chances east of I-25. This
will be nothing like the recent heavy rain events, with only a few
hundredths of QPF expected. The slow moving nature of this trough
will continue the shower and storm chances through the early week,
with up to a quarter inch possible in the panhandle Tuesday night.
The heavier amounts shift slightly west on Wednesday, with a
quarter to half inch possible along I-25. Highs Monday through
Wednesday will be back in the 70s before things warm back up
near the end of the period and the 90s return.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1135 PM MDT Wed Jun 18 2025

Upper level ridge axis is forecast to move into the region
over the next 24 hours and remain over the Front Range through
Friday. Dry and benign weather is expected with increasing winds
as we head into Friday.

HAZARDS/WEATHER TRENDS: VFR conditions will continue through 00z
Friday. Some LLWS expected for KCDR between 08z and 12z due to a
strengthening low level jet.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM...WFOCYS
AVIATION...TJT