259
FXUS65 KSLC 120430
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1030 PM MDT Tue Aug 11 2026

.KEY MESSAGES...

- A marginal risk of excessive rainfall will continue across much
  of Utah through at least Friday. This risk expands further north
  on Thursday and Friday.

- Temperatures will decrease 10-15 degrees by the end of the week
  with slightly drier air pushing into the area by the weekend.

&&

.DISCUSSION...Widely scattered rain showers with isolated
embedded thunderstorms will continue overnight, mainly across
portions of northwest and southeast Utah where two decaying
mesoscale convective systems are currently tracking through.
Showers will continue to slowly move northeast across these areas
into Wednesday morning.

Monsoon moisture remains in place across the region through
Friday. A stronger influx of moisture is expected today as the
ridge shifts eastward in response to a deepening trough along the
west coast. PWATs are expected to rise to around 1.0-1.1" areawide
Wednesday as a result, though nocturnal shower activity may
hinder convective development Wednesday afternoon in some areas if
conditions remain cloudy and stable. If storms are able to
develop Wednesday afternoon, they will be capable of producing
widely scattered showers and thunderstorms that bring an increased
risk for flash flooding, especially across southern and central
Utah.

The aforementioned trough brings more substantial cooling aloft
Thursday and Friday as it continues to deepen across the West,
resulting in increased instability across much of Utah and
southwest Wyoming through this period. Increasing upper level flow
will also produce more notable amounts of shear that will allow
for more organized, widespread convection through this period.
As such, the flash flood threat becomes more widespread across
most of Utah and southwest Wyoming given deep monsoon moisture
still in place. A welcome change arrives in the form of much
cooler temperatures Thursday and Friday, given the increased
cloud cover and cooling aloft from this system. Highs will run
about 10-15 degrees cooler through this period.

A drier airmass works into the region under southwesterly flow
this weekend. Very limited instability will also work to limit
convective activity, with storms mainly remaining confined to the
high terrain. The trough that brings drier southwest flow this
weekend is expected to retrograde westward off the west coast
early next week, with our typical monsoonal ridge redeveloping
once again in its place.

&&

.AVIATION...
KSLC...VFR conditions are expected to prevail through the valid
TAF period. Winds will most likely prevail out of the south
through the rest of the night and into Wednesday morning. There is
a 30-40% chance of periodic rain showers between 10z-16z. Winds
may be occasionally erratic near these showers. A transition to
northwest winds is expected around 19z Wednesday, with a 30%
chance of showers and thunderstorms in the afternoon thereafter.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to
prevail over the airspace through the valid TAF period with
generally light and terrain driven winds outside of showers.
Scattered rain showers will continue across northern Utah through
the night, with more isolated showers across southern Utah.
Wednesday afternoon, another round of scattered showers and
thunderstorms can be expected across the airspace. Thunderstorms or
stronger showers that develop will be capable of producing gusty and
erratic winds with a chance of mountain obscurations and temporary
MVFR conditions from heavy rainfall.

&&

.FIRE WEATHER...Monsoon moisture will continue to surge into Utah
through the remainder of the week with storms developing during the
afternoon and weakening late evening and overnight. Some nocturnal
activity will remain and persist, but the details of when and where
with these storms will likely remain uncertain until the day of.
Storms will be capable of producing gusty and erratic outflow winds
along with frequent lightning and brief heavy rain.

A storm system approaches by Thursday that will increase southwesterly
winds, but RH will remain elevated. This storm system will help to
expand precipitation across most of northern Utah, persisting through
Friday. Temperatures will cool 10-15 degrees across the area as this
system brings a cooler airmass. By the weekend, a slightly drier
airmass will limit most of the diurnal storms to the high terrain
before better moisture returns next week.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

PUBLIC...Whitlam
AVIATION...Cheng
FIRE WEATHER...Mahan

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity