739
FXUS65 KRIW 261904
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
104 PM MDT Thu Sep 26 2024

.KEY MESSAGES...

- Well above normal temperatures continue the next several days.

- Elevated to critical fire weather concerns continue through
  early this evening.

- Much cooler starting early next week, but precipitation
  chances remain near zero through next week.

&&

.DISCUSSION...
Issued at 1253 PM MDT Thu Sep 26 2024

Mostly clear skies continue today as the H5 ridge remains the
dominant feature across Wyoming. A trough along the Canadian
border is bringing a weak front across Montana, which will be
pushing into far northern Wyoming late this afternoon, bringing
a brief but brisk north wind. Ahead of this front, west winds
have been gusting 25 to 30 mph at times. This along with much
drier air is bringing critical fire concerns to central and
southern WY. See the fire discussion below for more details. All
winds will be decreasing early this evening as the trough moves
quickly east, relaxing the pressure gradient.

Friday and Saturday will again be warmer than normal, with
lighter winds continuing. Highs again reach the 80s for most
lower elevations, with humidity levels falling to around 15
percent each afternoon.

Sunday the next trough starts to sweep in fro the north. Unlike
the current one, this one will be much farther south, and will
have a better "cold" air push. Winds Sunday will again gust 25
to 35 mph, and with dry air still in place, fire concerns will
again be elevated. Behind the front, a much cooler airmass will
sweep southward across Wyoming Sunday night. This will be
evident with much cooler temps on Monday, with a 20 to 30 degree
drop between Sunday and Monday. Unfortunately, this system has
minimal moisture available with it, so precipitation is not
expected as the system passes.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1046 AM MDT Thu Sep 26 2024

Prevailing VFR/SKC conditions continue through the TAF period. Wind
will increase this afternoon as a trough slides east through MT.
Most terminals will have wind gusts ranging from 15-25 knots this
afternoon. A weak cold front will push south this evening, resulting
in a wind shift to more northerly at KCPR through the overnight
hours. Wind will decrease shortly after sunset at most terminals and
remain light through Friday as high pressure redevelops in the area.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on icing and turbulence forecasts.

&&

.FIRE WEATHER...
Issued at 1253 PM MDT Thu Sep 26 2024

Red Flag WArning continues through this evening for much of
central and southern Wyoming. Winds have come up above 15 mph
sustained, with gusts of 20 to 30 mph along the I-25 and I-80
corridors. Winds across Johnson County are expected to switch
this afternoon fro the north with a weak frontal boundary, with
gusts from the north near 25 mph. All winds decrease early this
evening, and will be much lighter Friday and Saturday. Sunday
will be another dry and gusty day, with Warnings again expected
during the day.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MDT this evening for WYZ279>281-
289.

&&

$$

DISCUSSION...Straub
AVIATION...Rowe
FIRE WEATHER...Straub