Cody, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

884
FXUS65 KRIW 201019
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
419 AM MDT Sun Jul 20 2025

.KEY MESSAGES...

- Red Flag Warnings are now in effect for portions of southern
  and central Wyoming from 12 PM to 8 PM Sunday due to low
  relative humidity and gusty westerly wind.

- Elevated to critical fire weather conditions will return
  across the area Monday, with central portions having the best
  chances for critical chances.

- Virga showers/dry thunderstorms will be confined to Sweetwater
  County and Yellowstone this afternoon, with widespread chances
  returning Monday. Chances for afternoon and evening showers
  and thunderstorms will be in place Tuesday through Friday.

&&

.DISCUSSION...
Issued at 146 AM MDT Sun Jul 20 2025

Drier and warmer conditions return today, with elevated to critical
fire weather conditions in place for most areas. Will upgrade the
Fire Weather Watch to Red Flag Warnings and add zones 277, 282, 283
and 288. Critical RH values, as low as 9 percent, will be widespread
across much of the CWA today. West-southwest winds, with gusts of 25
to 30 mph, will develop late this morning and also be widespread in
the afternoon. Higher gusts up to 35 mph will occur over the western
mountains, especially across Yellowstone and the Absarokas. Big
Horn, Washakie and northern Johnson County will have the weakest
winds around 20 to 25 mph. Isolated virga showers/dry thunderstorms
are still progged over portions of Sweetwater County this afternoon,
 as well as far northern portions of Yellowstone NP. This convection
will end by sunset. Wind gusts of 50 to 60 mph will once again be
possible from these passing showers.

A closed low will develop over the PACNW from a broad trough over
southern Canada during the day Monday. Heights will increase over
the Cowboy State as a result, as winds aloft turn more
southwesterly. This will lead to a ridge axis to build over the
region, extending from a strong high over the Gulf Coast. Hot and
dry conditions, with elevated to critical fire weather conditions
occurring once again. Critical fire weather conditions look to be
confined to central portions. Virga showers and dry thunderstorms
will be more widespread Monday afternoon, as upper level divergence
increases ahead of the digging upper low, in addition to the
proximity of the sfc low and frontal boundary over southern MT and
eastern ID. Wind gusts of 50 to 60 mph will continue to be the main
threat. The best instability, 200-500 J/kg, will be over northern
portions, small hail could be a possibility with the storms in this
area.

Drier conditions are expected Tuesday, as the aforementioned closed
low fills and lifts over MT/southern Canada during the day Tuesday.
Convection will be more isolated as a result. Fire weather
conditions will remain elevated to near-critical. Another upper low
will move over the region Wednesday, with areas east of the Divide
looking to have the best chances for precipitation. A ridge will
begin to reestablish itself over the region Thursday, as a closed
low sits off the northern CA coast. This will allow for Pacific and
monsoonal moisture to stream northward and subtle embedded
shortwaves to kick off afternoon convection.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 417 AM MDT Sun Jul 20 2025

Sunday will see an increase of gusty winds by late morning,
with most areas gusting 20 to 25kts by then. Skies will be VFR,
with only some high cirrus for most locations. We can`t rule out
a virga shower in vicinity of KRKS or KCOD between 20Z and 00Z
but the chance is less than 1 out of 5 so not enough confidence
to include in the TAFs at this time. Light winds return around
sunset Sunday evening as the atmosphere decouples.

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

&&

.FIRE WEATHER...
Issued at 146 AM MDT Sun Jul 20 2025

The Fire Weather Watch has been upgraded to a Red Flag Warning,
with zones 277, 282, 283, 287 and 288 added to the Warning.
Winds will quickly increase across the area between 1100 and
1400, with gusts of 25 to 30 mph. Higher gusts up to 35 mph will
occur over zones 140, 286, 415 and the higher peaks of the Wind
River Mountains. Zones 275, 276 and 281 will have near-critical
conditions, as either winds are not expected to reach criteria
or RH values will not drop below 15 percent. RH recovery will
continue to be fair to poor for most areas tonight.

Critical RH values will not be as widespread Monday and be
mostly confined to zones 280, 283 and 289. This will be due to a
slight increase in moisture that will lead to chances for virga
showers and dry thunderstorms being more widespread across the
forecast area.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon today to 8 PM MDT this evening for
WYZ277>280-282-283-287>289.

&&

$$

DISCUSSION...LaVoie
AVIATION...Hattings
FIRE WEATHER...LaVoie