972
FXUS65 KSLC 201131
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
531 AM MDT Thu Aug 20 2026

.KEY MESSAGES, Issued 1002 PM MDT Wed Aug 19 2026...


- Building high pressure will bring a steady warming trend in
  temperatures through Thursday across the south and through
  Friday across the north.

- Monsoon moisture will move back into Utah and southwest Wyoming
  late in the week, persisting through at least early next week.
  This will bring an increased threat of showers and thunderstorms
  capable of producing flash flooding.

&&

.DISCUSSION, Issued 1002 PM MDT Wed Aug 19 2026...
High pressure centered over AZ this evening will
shift east on Thursday before ending up over NM/west TX over the
weekend where it is expected to remain in place into early next
week. This shift will initially aid in a continued warming trend
before bringing increased moisture into the area beginning during
the Thursday/Friday timeframe. Current PWATs of around 0.8 inches
is expected to increase to 1-1.1 inches across the area by
Saturday afternoon.

Expect afternoon highs of near to above 100 degrees in many
valleys on Thursday even as midlevel moisture starts to creep into
southern Utah. On Friday, as the moisture starts to surge into
southern and central Utah, temperatures there may begin to cool
but continue to trend slightly warmer or at least remaining near
persistence across northern Utah. This moisture, the initial surge
being associated with a vort max lifting through the area, will
then spread into northern Utah by Saturday, allowing for a cooling
trend thereafter. HeatRisk is in the Red (Major) category across
many valley areas on Thursday, then will become more confined to
northern Utah for Friday. Heat Advisories are in effect for west-
central through northwest Utah valleys as a result. The need for
any Warnings is diminished due to acclimation to hot temperatures
throughout the summer.

With the arrival of the moisture, expect increasing coverage of
showers and thunderstorms along with increasing heavy rain
potential into early next week. There is currently a Marginal Risk
of Excessive Rainfall across southern Utah Thursday and Friday.
This Marginal Risk will spread through the rest of the forecast
area for Saturday and Sunday.

The high pressure looks to slowly start building westward again by
the middle of next week. Depending on how for west the high center
ends up (as there is still some model spread in this regard), the
airmass may start to gradually dry for the second half of next
week.



&&

.AVIATION... KSLC...VFR conditions will persist for the KSLC
terminal through the period. Dry and stable conditions with mostly
clear skies will continue with light diurnally driven winds.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for
the entire airspace through the period. Dry and stable conditions
will continue across most of the airspace with some isolated
convection across the eastern airspace this afternoon. Winds will be
relatively light and diurnally driven.

&&

.FIRE WEATHER, Issued 256 AM MDT Thu Aug 20 2026...
High pressure continues to strengthen across the area
with high temperatures today and Friday ~10 degrees above normal
for this time of year. While moisture is starting to increase across
the region there still remains quite a bit of dry air at the surface.
This will keep minimum RH in the upper single digits to 20s across
the entire area today. These will improve over the next several days
as moisture continues to surge into the area.

As for storms, isolated afternoon thunderstorms will develop across
the terrain and portions of eastern Utah. Given the dry surface these
storms will struggle to produce wetting precipitation across the lower
terrain with strong gusty outflow winds and frequent lightning being
the more likely outcome. By Friday afternoon storms will become more
widespread across the state with wetting rain chances increasing.
Temperatures will trend down to near normal this weekend as increased
cloud cover and diurnal storms keep temperatures tapered. This moisture
will stick around through the weekend and into early next week with
southwesterly winds increasing late weekend.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Heat Advisory from noon today to 7 AM MDT Saturday for
     UTZ101>106.

     Heat Advisory from noon today to 7 AM MDT Friday for UTZ115-116.

WY...None.
&&

$$

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

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