516
FXUS65 KRIW 291029
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
429 AM MDT Wed May 29 2024

.KEY MESSAGES...

- A weather system brings more widespread rain shower and thunderstorm
  chances to the area today. It will also be breezy across the
  area.

- The end of the week looks dry and a bit cooler after the
  system passes on Wednesday. Then, slight chances for
  thunderstorms on Saturday and Sunday.

- Monday looks hot and dry once again before another shortwave
  clips the area on Tuesday, with more rain shower/thunderstorm
  chances.

- Long-range model guidance continues to indicate a hot and dry
  period beginning late next week as a dominant ridge sets up
  over the western US.

&&

.DISCUSSION...
Issued at 316 AM MDT Wed May 29 2024

A more meaningful shortwave will pass through today, with more
widespread rain showers and thunderstorms this afternoon/evening.
The SPC has upgraded northern portions of the State to a Marginal
risk for severe weather this afternoon. The only threats are strong
to damaging wind gusts and frequent lightning, but small hail is
possible (40%) as well. This shortwave will bring breezy conditions
today. Temperatures will be about 10 degrees cooler across
northwestern portions of the area due to increased cloud cover and
rain, elsewhere temperatures will be similar to Tuesday. A Rangeland
Fire Danger Statement has been issued for this afternoon due to the
breezy wind, low RH, and warm temperatures. After this system moves
through it will be warm and mostly dry through Friday. Another
slight chance (20-30%) of rain showers/thunderstorms this weekend as
another quick moving shortwave will slide through the Cowboy State.
Minor river flooding is possible (30-40%) through tonight due to
mountain snowmelt as temperatures remain warm today, but as it
stands right now all rivers are behaving.

Overall, it will be an unsettled weather pattern with shortwaves in
mostly zonal flow through this weekend into next week. The
shortwaves will all be quick moving and weak, so not expecting big
precip makers or highly impactful weather into next week. It will be
fairly breezy for most locations beginning today and continuing into
next week. The breezy conditions, combined with low RH will lead to
elevated fire weather conditions later this week through this
weekend, although greenup will limit this threat. The amplified
ridge that model guidance was indicating for next week now looks
like it will develop a bit later as another trough slides through on
Tuesday. Regardless of the active pattern temperatures will not drop
all that much as each trough/shortwave should stay north as they
pass through the region.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 421 AM MDT Wed May 29 2024

VFR conditions expected throughout the period for all TAF sites.
Light winds and increasing mid to upper level clouds throughout
the morning timeframe. Winds will increase after 18-19Z with
gusts up to 25kts possible at all locations. Widely scattered
rain showers and isolated thunderstorms expected after this
point as well, west to east through around 01-04Z as it exits
east. RKS will be south of the activity and remain dry
throughout the period. Otherwise, scattered mid level clouds and
decreasing winds after this point into the overnight hours
through the end of the period Thursday morning.

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

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Rowe
AVIATION...Lowe