097
FXUS65 KCYS 300821
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
221 AM MDT Mon Sep 30 2024

.KEY MESSAGES...

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

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

- Warning level winds possible Tuesday night to Wednesday
  morning for the Interstate 80 wind prone areas.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 220 AM MDT Mon Sep 30 2024

Surface low located near Minot North Dakota. Cold front with
this low currently lays along a line from northwest South Dakota
to Buffalo Wyoming to Cody Wyoming. Really dry air behind this
front with Tds in eastern Montana in the upper teens. Getting
some pretty high wind gusts post frontal as well with 36kts
being reported from the Lewiston and Jordan Metars in Montana at
08Z.

Forecast looks on track with the cold front moving into northern
Converse and Niobrara Counties in the next hour or so. Then into
the central part of the CWA by 12Z and through Cheyenne by 15Z.
A much cooler day compared to Sunday with highs in the 60s and
low 70s. Still...with that really dry air behind the front
expected to move into the CWA...critical fire weather conditions
are still going to occur.

Upper shortwave tracks eastward into Minnesota tonight with the
front moving eastward as well. Westerly winds return and begin
to increase Tuesday morning. Went ahead with a Fire Weather
Watch for Tuesday.

Later shifts will need to keep an eye on strong winds in the
Interstate 80 wind prone areas Tuesday night into Wednesday
morning as the GFS showing 700mb winds up near 50kts. Craig to
Casper 850/700mb height gradients up near 52/43 mtrs at 06Z
Wednesday. Did increase winds at Arlington and over the I-80
Summit for that timeframe.


&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Issued at 220 AM MDT Mon Sep 30 2024

Prolonged warm and dry weather will continue for the long term
forecast and once again advertising above average temperatures
expected. Upper level pattern will see some breakdown to the
blocking pattern that plagued the region days prior with shortwave
disturbances passing overhead and propagating downstream,
transitioning the flow towards a more zonal pattern towards the
middle of the work week. While this will bring temperatures more in
line with what would be expected during Fall, it will be relatively
shortlived with a breakdown of the zonal flow as a new upper level
ridge begins building from the Western Seaboard through to the
Intermountain West as early as Late Thursday night and persisting
through the weekend. As a result, likely to see the return of above
average temperatures, with the strongest signals for well above
average temperatures on Saturday where the NAEFS mean 700mb
temperatures are in the climatological 90th percentile for the
majority of areas across southeast Wyoming and the Nebraska
Panhandle. As been the trend over the last week, will need to
continue blending in higher NBM percentiles to the current long term
model blends to slowly increasing daytime highs, in addition to
continue monitoring fire weather concerns with critical threshold
minimum humidity values for the foreseeable future.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1117 PM MDT Sun Sep 29 2024

VFR conditions expected across area terminals through the
forecast period. Gusty southerly winds continue late this
evening across the Pine Ridge and near KCDR with gusts 25-35 kt.
A cold front will sweep across the region early Monday morning
switching winds to out of the north starting around 11z by KCDR
and 13z near KCYS/KSNY. Gusty northerly winds will continue
behind the frontal passage into Monday afternoon.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 7 PM MDT this evening for WYZ417.
     Red Flag Warning from 11 AM this morning to 7 PM MDT this
     evening for WYZ418-421>423-425-427-428-433.
     Fire Weather Watch from Tuesday morning through Tuesday
     evening for WYZ419>423-425-427>429.
NE...Red Flag Warning until 7 PM MDT this evening for NEZ434.
     Red Flag Warning from 11 AM this morning to 7 PM MDT this
     evening for NEZ435>437.

&&

$$

SHORT TERM...GCC
LONG TERM...MRD
AVIATION...MB