851
FXUS65 KCYS 311951
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
151 PM MDT Fri May 31 2024

.KEY MESSAGES...

- Daily chances for isolated to scattered showers and  thunderstorms
continue through the weekend. A few storms may  have the potential
to become strong to severe each day.

- Warm and dry weather is expected most of next week, aside from  an
uncertain potential for a cold front which could bring some
shower/storm activity on Tuesday or Wednesday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 150 PM MDT Fri May 31 2024

Surface high pressure located over southwest South Dakota this
afternoon creating an easterly surface wind component over the
eastern half of the CWA. Stratus this morning east of the
Laramie Range has been persistent and slow to break up in
southeast low level upslope flow. 1PM temperatures remain quite
cool with upper 50s in the Panhandle and southeast Wyoming
plains east of the Laramie Range. Cheyenne finally broke out
maybe an hour or so ago. Latest SPC Mesoanalyst page showing
quite a bit on CIN across the Panhandle into southeast Wyoming
in these southeast winds and stratus. Where skies are
clearing...current SBCAPE has risen to 500-1000 J/KG across
western Laramie County into southern Platte County. Lack of
surface heating from the low clouds shows SBCAPE not rising too
much through the afternoon with low level CIN returning by 00Z.

Given the persistent stratus...do not think we will see much
this afternoon convection wise. Another late night show possible
as a dry cold front drops into the southeast Wyoming plains as
parent upper shortwave tracks across eastern Montana and western
SOuth Dakota. HRRR and RAP simulated radar showing convection
developing across the northern Nebraska Panhandle towards 06Z
tonight that could become strong to severe for a time through
11Z.

Really questionable on severe convection Saturday as GFS showing
really dry air pushing into the Panhandle. Dryline on the GFS
pushes through the Panhandle by 21Z Saturday. So its not
matching up well with peak heating. Confidence not high on
severe convection Saturday afternoon/evening and the SPC Slight
Risk area. Guess it depends on timing of the dryline moving
eastward. A slower timing would improve severe convection
chances. Later shifts will need to watch the timing of the
dryline push.

As for Sunday...it all depends on the timing of the dryline
push on Saturday. Could see a dry forecast for Sunday...but for
now...kept chance PoPs (30-40 percent) for Sunday afternoon.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Issued at 150 PM MDT Fri May 31 2024

The long term looks relatively uneventful with mostly dry and mild
conditions expected throughout next week. Quasi-zonal flow for the
first half of the work week will lead to breezy and windy conditions
across much of the CWA. A strong shortwave trough passing just to
the north of the CWA on Tuesday will lead to the greatest potential
for high winds across the southeast Wyoming wind prones. The GFS has
700 mb wind speeds of 50 to 60 kts, and elevated CAG to CPR 700 mb
height gradients. In-house guidance is also pinging the potential
for high winds around the wind prones. Cannot rule out some slight
precipitation chances with the passage of this shortwave either.
Cooler temperatures can also be expected on Tuesday as the shortwave
ushers in slightly cooler 700 mb air. By Wednesday, ridging begins
to build over western CONUS, leading to a warmer and drier airmass
infiltrating the CWA. Temperatures through Friday will gradually
increase, with most locations seeing highs in the 80s by Friday.
Minimal precipitation chances are expected during this time frame as
subsidence keeps conditions dry.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1151 AM MDT Thu May 31 2024

Westerly flow aloft will prevail.

Wyoming TAFS...At Rawlins and Laramie, scattered clouds around 10000
feet will occur, otherwise clear skies will prevail. Winds will gust
to 27 knots until 01Z, and to 25 knots at Rawlins after 15Z Saturday.

At Cheyenne, ceilings near 1500 feet will improve to 5000 to 8000
feet through 12Z, then skies will be clear.

Nebraska TAFS...At Chadron and Alliance, ceilings will range from
3500 to 7000 feet through the afternoon, then scattered clouds will
be around 7000 feet until 06Z, then fog will reduce visibilities to
2 miles with ceilings near 1500 feet until 15Z, then ceilings will
be around 3500 feet.

At Scottsbluff and Sidney, ceilings will improve from 2500 feet to
3500 feet early this afternoon, then scattered to broken clouds from
3500 to 5000 feet will occur this evening, before fog reduces
visibilities to 2 miles and ceilings to near 1500 feet from 06Z to
15Z, then scattered to broken clouds around 3500 feet will occur.

&&

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

&&

$$

SHORT TERM...GCC
LONG TERM...SF
AVIATION...RUBIN