235
FXUS65 KCYS 041749
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1149 AM MDT Thu Jul 4 2024

.KEY MESSAGES...

- It will be much cooler across much of the area today in the
  post frontal air mass. Daytime highs are expected to remain in
  the 70s for most locations.

- Near to slightly below normal temperatures will persist over
  the next several days, with daily chances for isolated to
  widely scattered showers and thunderstorms. The threat for
  strong to severe thunderstorms should remain limited through
  at least Friday.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 353 AM MDT Thu Jul 4 2024

A generally quiet forecast period across southeast Wyoming & the
western Nebraska Panhandle w/ just a few weak mid or upper-level
disturbances embedded within northwesterly flow aloft. There may
be occasional chances for showers or thunderstorms over portions
of the CWA, but with the majority of the vort energy expected to
be focused further to the north across the northern high plains/
western Dakotas, believe any such activity will most likely stay
fairly isolated as suggested by multiple CAMs. Better convective
chances may arrive Saturday afternoon as the GFS/ECM suggest the
arrival of a much more defined short wave digging southeast into
the Intermountain West and central Rockies by 00z Sunday. Severe
potential is uncertain given a fairly persistent WNW lower-level
flow pattern impacting the overall moisture quality, but overall
shear profiles should support organized convection w/ increasing
mid-level flow. Other than chances for showers & storms, it will
be rather cool today in the wake of last night`s cold fropa with
700-mb temperatures plunging to +2 to +6 deg C. Daytime highs do
not appear likely to reach 80 deg F w/ most areas likely staying
in the 70s at best. While a slow warming trend may occur through
Saturday, the continued influence of the larger scale broad mid/
upper level trough over the Upper Midwest & Great Lakes may keep
temperatures seasonably cool with temperatures remaining near or
slightly below normal through the period.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Issued at 353 AM MDT Thu Jul 4 2024

By Sunday, the CWA will be post-frontal, with below average high
temperatures expected. A strong cold front will likely traverse the
CWA Saturday night, dropping 700 mb temperatures on Sunday into the
+8C to +4C range. This is enough to put 700 mb temperatures in the
10th percentile for NAEFS mean. These cool temperatures will limit
daytime highs, with most locations not making it out of the 70s.
Could also see some precipitation behind the front. A weak vort max
will drop into the CWA which could trigger some weak showers in and
around the high terrain. Any precipitation will be short lived as
the main trough axis shifts into the central plains by Sunday
night.

With the trough axis gradually pushing eastward, a strong ridge will
build over much of western CONUS, taking its place. This will lead
to a warming trend throughout much of next week, and possibly a
return to 90 degree temperatures by mid-week. During this time, the
strengthening ridge will raise 500 mb heights across the CWA. This
will contribute to minimal precipitation chances throughout the
remainder of the long term forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1142 AM MDT Thu Jul 4 2024

VFR conditions expected for the forecast period. Breezy NW winds
will weaken and shift more northeast around sunset, with normal
diurnal winds resuming after midnight. A few showers/weak
thunderstorms are possible this afternoon around KCYS and KCDR.
Another round is possible between about 04z and 10z, mainly
around KBFF.

&&

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

&&

$$

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