975
FXUS65 KRIW 010843
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
243 AM MDT Tue Jul 1 2025

.KEY MESSAGES...

- Warm temperatures prevail across the state with isolated
  chances for showers and thunderstorms during the afternoon
  and evening.

- An influx of moisture will create increased chances for daily afternoon
  showers and thunderstorms starting Wednesday.

- Unsettled weather continues into the second half of the week
  with widespread chances for showers and thunderstorms on
  Thursday and Friday.

&&

.DISCUSSION...
Issued at 242 AM MDT Tue Jul 1 2025

June has concluded and today marks the start of July. The upcoming
weather pattern for the beginning of July is looking warm and
unsettled across much of the Cowboy State. Warm, above normal
temperatures are forecast over the next few days. Daily chances for
showers and thunderstorms are expected through the remainder of the
week. Southwesterly flow will usher in well above normal PWAT values
for Wednesday through Friday. Convection chances will increase
around the same time with daily coverage becoming more widespread
starting Wednesday.

Today, the first day of July, as mentioned earlier will be warm with
above normal temperatures. Highs today will range from the mid to
upper 80s west of the Divide and low to mid 90s east of the Divide.
An upper level low moving into the Western CONUS today will be the
key weather maker through the week. Multiple small disturbances will
move across the area over the week bringing daily chances for
showers and thunderstorms. Tuesday will see fairly limited
convection being mainly isolated to scattered in nature during the
afternoon and evening. One thing to keep in mind is that the
atmosphere will still be rather dry, which will limit storm
development and likely produce mainly virga showers. These showers
and thunderstorms will be capable of producing some strong outflow
winds due to large dewpoint depressions of 40 to 60 degrees in some
locations, especially southern WY. Showers and thunderstorms will
dissipate shortly after sunset.

Wednesday will see much of the same with warm above normal
temperatures and afternoon showers and thunderstorms. The one
difference will be the influx of well above normal moisture. The
aforementioned upper level low over the western CONUS will aid in
funneling moisture into the region. Models show PWAT values of 0.60
to 0.90 inches which would be nearly 100 to 150% above normal. This
moisture will aid in creating more widespread development of showers
and thunderstorms. The strength of any storms that develop will
still be fairly minimal as CAPE values only look to be around 500-
800 J/kg. Other favorable dynamics are not expected to be in place
which should limit any strong storm development.

Thursday will see the warm and unsettled pattern continue. However,
moisture is expected to increase further with PWATs nearing 1 inch
translating to almost 200% above normal values. This will increase
the chances for periods of heavy downpours as showers and
thunderstorms develop and move across the state during the afternoon
and evening. While storm motion is not expected to be stationary
there will still be the potential for some isolated flash flooding
as a result of this increased influx of moisture. The other concern
that develops on Thursday will be increased chances for strong
thunderstorms. These increased chances are due to higher CAPE values
along with more favorable dynamics as a result of a leeside low
developing over the Northern Plains. While still a few days out the
best chances for strong thunderstorms would be across eastern WY
including portions of Natrona and Johnson Counties.

Looking ahead towards the 4th of July, the unsettled weather
persists with widespread chances for showers and thunderstorms.
Temperatures will cool slightly compared to earlier in the week,
returning to near seasonable values. Above normal PWATs linger which
would create another day with chances for heavy downpours and
isolated flash flooding. The best chances are currently looking to
be across central and northern WY. These may create some
difficulties when it comes to Independence Day celebrations. While
the forecast is not set in stone, it is starting to look more likely
that Friday may be quite unsettled for much of the Cowboy State.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1024 PM MDT Mon Jun 30 2025

VFR cigs and light winds continue overnight tonight. Daytime
heating will bring SCT CU to most areas, but these will remain
well above 3000ft. During the afternoon, scattered showers and
thunderstorms will develop and move east across western WY. Have
expanded the threat for -tsra with PROB30 groupings into
KLND/KRIW, leaving KWRL and KCPR as sites with minimal shower
chance before sunset. Any showers that do form will be
accompanied by variably gusty winds. Showers will focus on the
21z to 00z period, and will quickly decrease during the
evening.

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

&&

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

&&

$$

DISCUSSION...Dziewaltowski
AVIATION...Straub