488
FXUS65 KRIW 061914
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
114 PM MDT Sat Jul 6 2024

.KEY MESSAGES...

- Seasonable and pleasant across the Cowboy State today.
  Scattered showers and thunderstorms are possible this
  afternoon and evening.

- Elevated to critical fire weather conditions will be possible
  in central and southern WY today. Red Flag Warnings have been
  issued for parts of Fremont and Natrona Counties.

- Cooler temperatures for Sunday before a potent area of high pressure
  builds over the region for the upcoming week.

- Near record breaking heat possible by the second half of the
  week with highs in the upper 90s. Some areas may even see
  highs meet or exceed 100 degrees.

&&

.DISCUSSION...
Issued at 113 PM MDT Sat Jul 6 2024

Seasonable and pleasant weather is expected across the Cowboy State
today. Highs today will be around normal for this time of the year,
with values near 80 east of the Divide and in the upper 70s west of
the Divide. Scattered showers and thunderstorms are possible this
afternoon and evening. Most of the convection is expected to remain
east of the Divide. The one concern for today will be elevated to
critical fire weather conditions across parts of the CWA. Due to the
favorable winds, and low RH values, Red Flag Warnings have been
issued for parts of Natrona and Fremont Counties.

A deep trough is currently digging across the central CONUS with the
back end moving across the region. Northwesterly flow is expected to
develop today, which will aid in the development of showers and
thunderstorms this afternoon and evening. Convection is expected to
begin as a cold front moves across the CWA. Dynamics are not that
favorable for concerns regarding hazards from any convection that
develops. The one thing to monitor will be strong gusty outflows due
to inverted-V profiles, with many places seeing 40-50 degree
dewpoint depressions. Models show the best chance of thunderstorms
being across parts of the northern and eastern CWA with a (20-40%)
chance. Overall, precipitation chances range from (20-50%), with
higher probabilities in the northern and eastern parts of the CWA.

Aside from showers and thunderstorms, the other concern today will
be gusty winds and low RH values, which will create elevated to
critical fire weather conditions at times. Winds will begin to
increase this afternoon as the cold front starts to move across the
CWA. Gusts of 25 to 35 mph are likely with much of the state seeing
(40-70%) chance of seeing gusts exceeding 30 mph. As mentioned
earlier, there is a possibility for isolated stronger gusts in
association with any developing showers or thunderstorms. RH values
are forecast to remain low, ranging from 10-15% in central and
souther pars of the CWA. Due to critical fuels, Red Flag Warnings
have been issued for parts of Fremont and Natrona Counties due to
the combination of warm temperatures, low RH values, gusty winds,
and dry fuels.

Sunday will be a nice palate cleanser, as cooler temperatures move
in behind the cold front. Temperatures are expected to be 5-10
degrees cooler than today with most of the state seeing highs in the
70s. Winds will be lighter as high pressure from the West Coast
begins to build into the region. Showers are still possible Sunday
but are going to be more isolated in nature compared to today.

The upcoming week will see a return to the hot mid-summer heat, as a
potent high pressure builds over the region. The heat will gradually
build through the week with the hottest temperatures forecast to
develop by the second half of the week. Models currently show a (30-
60%) chance of seeing 95 degrees or higher temperatures in parts of
the central and eastern CWA. Models even indicate the possibility of
some places reaching or exceeding the century mark, especially in
the Bighorn Basin. Taking a peak at some of the climate data, there
is a chance that some records may be in jeopardy of being tied or
broken. Overall, this high pressure definitely means business with
many records already being broken in parts of the Western CONUS. The
upcoming week will need to be monitored to see what degree of heat
we see in our CWA.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1114 AM MDT Sat Jul 6 2024

Brief reductions to MVFR possible at TAF terminals east of the
divide late this afternoon through overnight hours with showers
and thunderstorms moving through. The best chances for direct
impacts due to rain showers and thunderstorms are at KCOD,
KWRL, and KCPR, but showers are possible at KRIW and LND later
this evening. In addition, gusty north winds 25 to 35 knots are
expected ahead of and along the frontal passage through this
evening. Generally light and variable winds expected overnight
with clearing skies, following the rain showers and
thunderstorms.

&&

.FIRE WEATHER...
Issued at 209 AM MDT Sat Jul 6 2024

Warm temperatures today across central and southern WY will
bring very dry conditions this afternoon. Humidity levels will
be 10 to 15 percent generally south of a line from Riverton to
Casper, with the driest conditions across Sweetwater County. A
passing weather system will bring along gusty winds aloft, which
will mix down to the sfc during the afternoon. Expect frequent
gusts above 30 mph for this region during the afternoon,
decreasing around 8 PM this evening. Winds aloft turn more from
the north overnight, pulling increased moisture in from the
north. This will bring improved humidity readings for Sunday, so
fire weather threat will be decreased.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for WYZ280-283.

&&

$$

DISCUSSION...Dziewaltowski
AVIATION...Gross
FIRE WEATHER...Straub