184
FXUS65 KRIW 030822
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
222 AM MDT Thu Jul 3 2025

.KEY MESSAGES...

- Another day of widespread showers and thunderstorms with the
  main concern being heavy downpours and gusty winds.

- The 4th will see another round of showers and thunderstorms
  with activity possibly dying down in time for evening events.

- Quieter conditions are expected for the weekend with some
  isolated showers and thunderstorms possible.

- Hot and drier weather looks to return for next week with
  elevated fire weather conditions possible.

&&

.DISCUSSION...
Issued at 221 AM MDT Thu Jul 3 2025

Warm well above normal temperatures along with widespread showers
and thunderstorms enveloped the Cowboy State on Wednesday. Thursday
will see much of the same with a few exceptions, one being cooler
more seasonable temperatures and the other being an influx of
moisture. Temperatures for today will range in the mid 70s west of
the Divide and mid 80s to low 90s east of the Divide. As mentioned
earlier an influx of moisture will make its way into the region.
PWATs are expected to near 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. Storms will have the
potential to produce localized flash flooding especially in poor
drainage areas and susceptible urban areas. 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 shortwave trough
moving across the region. The best chances will be across central
and northern WY with the main hazards being small hail and strong
gusty outflow winds. Showers and thunderstorms will linger into the
late evening and early Friday morning before dissipating later in
the morning.

Looking towards Friday, the 4th of July, unsettled weather looks to
be likely. Temperatures will cooler compared to earlier this week,
returning to near seasonable values. Above normal PWATs linger which
would create another day with chances for heavy downpours. Models
show another shortwave move across the region with short range
models coming into fairly good agreement regarding impacts and
timing. Models indicate the best chances for showers and
thunderstorms being across central and northern WY. The remainder of
the state will have lesser chances for showers and thunderstorms but
cannot be completely ruled out. A brief period of clearing during
the morning and early afternoon may produce sufficient
instability to fuel some stronger thunderstorm development.
Along with this instability, more favorable dynamics will be in
place as this shortwave moves across the area. The best chances
for strong thunderstorm development looks to be across portions
of northern and eastern WY. The main hazards for Friday will be
small hail, strong outflow winds, and heavy downpours capable of
localized flash flooding especially in poor drainage areas. All
this information does make it seem like the day may be a
complete washout. However, convection is looking to dissipate
gradually during the evening and possibly by sunset. A few
isolated showers may be lingering after sunset but as a whole
activity should be dying down in time for 4th of July events.

The weekend is looking less active but will still have some chances
for showers and thunderstorms. Coverage of these showers and
thunderstorms will be less widespread with much of the state
remaining dry. Temperatures will be seasonable but begin to
gradually warm as ridging looks to start building in over the
western CONUS. A period of hot and dry conditions is beginning to
look more likely for the upcoming week. A big factor will be the
strength of the ridging and how long it can prevail over the region.
There is still time for things to change but as of right now the
July heat and dryness looks to be right around the corner. This
may lead to some elevated fire weather conditions so it will
need to be monitored as we head into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 927 PM MDT Wed Jul 2 2025

Any lingering rain showers or isolated thunderstorms will quickly
taper off within an hour or two to begin the TAF period. More
isolated showers are possible near KJAC Thursday morning before
widespread showers and storms develop in the afternoon. Moisture
values will be increasing during the day Thursday, so there is a
better chance for reduced VIS from the heavier downpours. As such,
have dropped VIS to 5SM for the majority of the PROB30 groups.
Scattered rain showers and isolated storms will linger well into
Thursday evening.

It will be a bit gusty at KRKS and KRIW Thursday afternoon,
otherwise wind will be around 10 knots outside of outflows and
downdrafts. Overall downdrafts and outflows should not be as strong
Thursday afternoon as low-level moisture will limit temperature dew
point spreads. Cloud heights will be a few thousand feet lower due
to the increased moisture as well. There is the possibility that
denser cloud cover will develop Thursday morning and prevent
convective initiation until later in afternoon.

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...Dziewaltowski
AVIATION...Rowe