284
FXUS65 KCYS 242036
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
236 PM MDT Tue Sep 24 2024

.KEY MESSAGES...

- Above average temperatures and dry conditions expected
  Wednesday onwards.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 233 PM MDT Tue Sep 24 2024

An upper-level ridge axis moving over the Rockies on Wednesday will
lead to anomalously warm 700 mb temperatures over the next two
days. According to NAEFS, the 14C to 16C 700 mb temperatures
expected on Wednesday and Thursday will be in the 99th
percentile of climatology. This will lead to afternoon highs
anywhere from 15 to 20 degrees above average! Thursday will be
the hottest day of the week with the possibility of some
locations either breaking or tying their high temperature
record! A shortwave passing north of the CWA will push the ridge
axis over the central plains. This will lead to strong zonal
flow over the area, contributing to downsloping winds and thus
the hotter temperatures expected on Thursday. Locations in the
Nebraska panhandle can expect widespread low to mid 90s Thursday
afternoon. Areas east of the Laramie Range in Wyoming can
expect highs in the upper 80s to mid 90s, and areas to the west
will be in the low 80s. Subsidence under this strong ridge will
keep conditions dry and precipitation chances at zero.
Therefore, expect elevated fire weather concerns over the next
few days.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Issued at 233 PM MDT Tue Sep 24 2024

Warm and dry weather will continue through the majority of the next
week. A shortwave trough passing well north of the area on Thursday
will knock down temperatures by about 5F for Friday`s highs, but
this will barely make a dent in the impressive ridge locked in over
the Western CONUS. The ridge will take over quickly after, and hold
warm temperatures and minimal precipitation chances through the
weekend. 700-mb temperatures in the NAEFS mean remain above the 90th
percentile of climatology through the weekend, supporting very warm
temperatures, but still slightly cooler than the peak on Thursday.
The next trough is expected to arrive in the late Sunday/Monday time
period, and this one does appear to be a bit stronger than the
previous. Still, the prevailing solution amongst ensemble members
keeps this as a dry frontal passage with a subtle temperature drop.
About 20% of members show the trough pushing close enough to bring a
more significant temperature drop with a more widespread
frost/freeze threat to start October, along with a chance for some
very light precipitation. The cool down will be short lived once
again though, with the ridge building back in towards the middle of
next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1130 AM MDT Tue Sep 24 2024

VFR expected for the forecast period, with clear skies
dominating once the remaining mid-level cloud cover breaks up
by mid afternoon. Occasional NW to N wind gusts to 20 kts this
afternoon, followed by light winds drifting around to southerly
by Wednesday morning.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...MN
AVIATION...MN