430
FXUS65 KCYS 011731
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1131 AM MDT Tue Oct 1 2024

.KEY MESSAGES...

- Prolonged dry conditions will raise fire weather concerns
  through Wednesday. Red Flag Warnings are in effect today from
  11 AM through Wednesday 7PM MDT.

- A small window for warning level winds in the wind prone areas
  of southeast Wyoming tonight through noon Wednesday where we
  may see some wind gusts to 60 mph.

- Warm, dry and breezy conditions expected each day of the week.
  Expect fire weather headlines on a daily basis through at
  least Friday.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 302 AM MDT Tue Oct 1 2024

Cold front that moved through the CWA now lays well south in
southern Colorado with a 1031mb surface high across western
Nebraska through northwest Wyoming. It is quite colder than 24
hours ago with Casper reporting 31 degrees at 2 AM and Chadron
reporting 35. Winds have yet to switch back to the southwest so
far this morning...but are expected to in the next couple hours.

For today...Seeing some really good warmup in 700mb
temperatures. GFS goes from +2 to +4C currently to +10 to +12C
this afternoon at 2100Z. Afternoon temperatures well into the
mid 70s expected today as upper ridge builds in from the
southwest.

The warmup and return of westerly winds will create another day
of critical fire weather conditions across the CWA. GFS 700mb
winds up over 30kts across Carbon and Albany Counties this
afternoon. Do believe the Red Flag Warnings will be a near slam
dunk to our western fire weather zones. What may be more of an
issue are our fire weather zones east of the Laramie Range. GFS
shows some pretty good 850mb winds across the northern Panhandle
at 25-30kts through 21Z this afternoon. Plus GFS sounding do
show the possibility of mixing down higher level winds. Went
ahead and upgraded all watches to warnings.

Very poor humidity recoveries still expected out west tonight as
gradients continue to increase. In fact...Craig to Casper
850/700mb height gradients up near 50mtrs as GFS 700mb winds
increase to 50kts. Could see strong winds in the wind prone
areas tonight into Wednesday morning. Decided on a High Wind
Watch for the wind prone areas and let the day crew make the
call on any upgrades.

Widespread critical fire weather conditions through the day
Wednesday. Especially our western fire weather zones. Day crew
may need to expand fire headlines east as GFS does show 750 to
800mb winds across Laramie County into the southern Panhandle
downsloping off the Laramie Range at 25-30kts.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Issued at 302 AM MDT Tue Oct 1 2024

Thursday night/Friday...Expect a decent warming trend as the flow
aloft turns westerly and heights and thicknesses rise. With 700 mb
temperatures near 14 Celsius, maximum temperatures will reach the
mid 70s to mid 80s. The low and mid levels of the atmosphere will be
too dry to support any precipitation.

Saturday...Very warm temperatures continue with readings in the
upper 70s to near 90 degrees. Still dry low and mid levels, so no
precipitation.

Sunday...Although ridging aloft develops to keep dry conditions in
place, temperatures will be a bit cooler with 700 mb temperatures
near 10 Celsius, and upslope south and southeast surface winds.

Monday...A weak shortwave trough aloft passes across the forecast
area, though conditions will remain dry with minimal low and mid
level moisture. A little warmer with 700 mb temperatures near 12
Celsius.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1127 AM MDT Tue Oct 1 2024

VFR expected at all terminals through the forecast period. LLWS
is anticipated for KCYS overnight and into early Wednesday
morning due to a short period of stronger wind gusts aloft. KRWL
and KLAR will also see elevated wind gusts overnight. Haze will
slowly move into the NE Panhandle terminals region by Wednesday
morning from nearby wildfire smoke. Please see individual TAFs
for further information.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 6 PM MDT this evening for WYZ417-418.
     Red Flag Warning until 8 PM MDT Wednesday for WYZ419>423-425-
     427>429.
     High Wind Watch from late tonight through Thursday morning for
     WYZ106-110-116-117.
NE...Red Flag Warning until 6 PM MDT this evening for NEZ434-435.

&&

$$

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