546
FXUS65 KCYS 041718
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1118 AM MDT Tue Jun 4 2024

.KEY MESSAGES...

- A widespread, prolonged episode of strong winds with gusts up
  to 65 MPH is expected from this evening through Wednesday
  afternoon. High Wind Watches and Warnings have been issued.

- Critical afternoon humidity expected each day this upcoming
  week that could create elevated to locally critical fire
  weather conditions.

- Friday through Monday will see increasing chances for
  afternoon and evening showers and thunderstorms. The warmest
  day will be Friday with slightly cooler temperatures for the
  weekend and Monday.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 225 AM MDT Tue Jun 4 2024

Surface analysis this morning shows a cold front just clearing
the Panhandle...southwest into central Colorado. Another cold
front analyzed across eastern Montana into northern Wyoming this
morning. Craig to Casper 850/700mb height gradients this
morning up near 61/54mtrs respectively which has produced strong
winds in Arlington and Bordeaux. Laramie Valley at Quealy Dome
reported wind gusts to 63 mph earlier...but has since really
backed off down to 17 mph gusts. Likely some mountain wave that
caused the strong winds at Quealy Dome earlier. Finally...for
northern Carbon County. Winds at the Camp Creek RAWS site have
eased some with gusts to 49 mph on their last observation.

Likely to see winds ease later today as Craig to Casper
850/700mb height gradients ease down to the 30s and 40s meter
range. But they crank up again this evening and surpass 70/61
mtrs by Wednesday morning. We will see a window this afternoon
where local Interstates will likely be open for light weight and
high profile vehicles to travel.

Kept the forecast dry today. HRRR and RAP simulated radar
showing no echoes over the CWA...so most if not all locations
expected to be dry. Began ramping up winds again after 03Z this
evening. Kept the High Wind Watch going for central Laramie
County for the second cold front as 750 winds up to 50-55kts
over Cheyenne and 800mb winds forecast 45-50kts. This looks to
happen after 06Z tonight...so a watch sounds like a good idea.

Second front looks to move into our northern CWA Wednesday
afternoon and across the I-80 Corridor around 00Z Thursday. This
will bring an end to the strong winds as winds turn
northeasterly behind the front.

For the rest of Thursday...we begin to see an upper level ridge
building into the area for sunny skies and warmer temperatures.
We can expect very dry afternoon humidity each day in the short
term. But given Fuels are all reported NO for rapid fire
spread...fire weather concerns expected to be minimal.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Issued at 225 AM MDT Tue Jun 4 2024

Thursday night/Friday...Relatively weak northwest flow aloft
prevails, and with adequate low and mid level moisture, we expect to
see isolated to scattered afternoon showers and thunderstorms from
Laramie to Cheyenne to Kimball, with the highest areal coverage near
the mountains. Most of the showers and thunderstorms will spread
eastward to the Nebraska Panhandle in the evening. This looks like
the warmest day of the long term with maximum temperatures in the
80s to near 90 degrees.

Saturday...A shortwave trough aloft moves overhead, along with its
associated cold front, which will provide cooler temperatures with
surface high pressure over the northern Plains states producing
northeast surface winds for our forecast area. With an increase in
low and mid level moisture, and low level upslope, we anticipate
scattered to numerous afternoon and evening showers and scattered
thunderstorms, most numerous near the Colorado state line.

Sunday...Ridging aloft becomes more pronounced across Wyoming,
though with northwest flow aloft continuing and adequate low and mid
level moisture along with low level upslope lift, we expect
scattered afternoon and evening showers and thunderstorms.
Temperatures will be similar to Saturday with abundant cloud cover,
with 700 mb temperatures near 9 Celsius yielding high temperatures
in the upper 70s to lower 80s.

Monday...Weak northwest flow aloft continues and with plenty of low
and mid level moisture available, scattered late day showers and
thunderstorms will be on tap again. Temperatures slightly cooler
than Sunday with more cloud coverage.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1113 AM MDT Tue Jun 4 2024

VFR is anticipated at all terminals through the forecast period.
Strong, gusty winds are expected for the southeast WY terminals
up to 40-50 knots this afternoon. LLWS is also anticipated for
KCYS and KLAR early Wednesday morning by 12z. The Nebraska
Panhandle terminals will experience wind gusts of 20-35 knots
this afternoon before tapering off overnight. They will once
again pick up shortly after sunrise for wind gusts of 20-30
knots through 18z Wednesday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning until noon MDT Wednesday for WYZ104.
     High Wind Warning until 6 PM MDT Wednesday for WYZ106-109-110-
     115>117.
     High Wind Warning until noon MDT today for WYZ107.
     High Wind Watch through Wednesday afternoon for WYZ118.
NE...None.

&&

$$

SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...BW