828
FXUS65 KSLC 192323
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
523 PM MDT Wed Aug 19 2026

.KEY MESSAGES, Issued 1033 PM MDT Tue Aug 18 2026...


- Building high pressure will bring a steady warming trend in
  temperatures through Thursday/ Friday as conditions dry.

- 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 131 PM MDT Wed Aug 19 2026...
Hot and dry conditions are expected to remain in
place across Utah and southwest Wyoming through the end of this
week as high pressure strengthens over the forecast area. With the
upper-level ridge axis cresting overhead Thursday through Friday,
anticipate some of the hottest temperatures across the forecast
area to fall on these days, especially for the central and
northern area. Across southern Utah, the heat is already in place
and will be more so maintained during this period of increasing
heat across the northern area. With high temperatures in the lower
lying valley areas across central and northern Utah reaching back
into the triple digits alongside low temperatures in the low- to
mid-70s, there will be an increased risk of heat related illness
on both Thursday and Friday. Slight moderation of heat is expected
on Thursday in central Utah as moisture gradually creeps
northward, increasing the amount of afternoon cloud cover and
potential for rain cooled downdrafts. As such, the increased heat
risk in central Utah is really only anticipated through Thursday
while northern Utah will maintain an elevated heat risk on both
days. Temperatures decrease across the northern area on Friday as
moisture spreads farther northward, decreasing the overall heat
risk as daytime high temperatures fall back into the low-90s
alongside sufficient overnight relief. Relatively cooler, more
seasonable temperatures are expected into early next week while
the elevated moisture is maintained.

Speaking of the moisture, the presence of mid-level moisture is
currently noted across the forecast area as afternoon heating has
allowed for isolated development of showers and thunderstorms over
the high terrain in central and northern Utah. This mid-level
moisture will remain in place across the central and northern area
on Thursday, with increasing lower level moisture anticipated
across southern Utah as the high pressure center begins to shift
over the Four Corners region. While coverage of showers and
thunderstorms are not expected to be widespread across southern
Utah on Thursday, whatever storms do form will bring potential for
heavier rainfall which may lead to flash flooding if they end up
in the wrong spot (i.e. slot canyons, dry washes, recent burn
scars, etc.). This threat will increase and expand farther
northward on Friday as the persistent high pressure center over
the Four Corners region helps to advect anomalous moisture into
the area.

By Saturday, much of Utah and soutwest Wyoming will see sufficient
coverage of above normal atmospheric moisture, expanding the risk
of heavy rainfall and flash flooding across the entirety of the
forecast area. This threat is expected to remain in place through
at least the Monday/ Tuesday timeframe, with potential to extend
into the middle of next week and beyond. In short, expect shower
and thunderstorm coverage each afternoon from Friday through
Tuesday over the high terrain features across Utah, with an
increased probability of heavy rainfall.



&&

.AVIATION... KSLC...The SLC terminal will see VFR conditions through
the overnight hours with some high clouds. Northerly winds are
expected to shift to the south between 03Z and 05Z.

REST OF UTAH AND SOUTHWEST WYOMING...The airspace will see VFR
conditions with generally light and terrain driven winds through the
overnight hours. Isolated showers and thunderstorms will continue
over southeast Utah through the early evening before dissipating.
Any storms that develop will be capable of producing gusty and
erratic thunderstorms winds, lightning, and brief mountain
obscurations.

&&

.FIRE WEATHER, Issued 131 PM MDT Wed Aug 19 2026...
Strengthening high pressure will continue to bring a
trend of warming and drying across Utah, with high temperatures
in many lower lying valley areas reaching back into the triple
digits. Alongside the heat, further drying is expected across
Utah`s West Desert on Thursday with humidity falling by another 5
percent. As such, isolated pockets of single digit humidity are
expected in the West Desert on Thursday afternoon. On a positive
note, winds will remain generally light and terrain driven through
the heat and low relative humidity, keeping significant fire
weather concerns low. High-based moisture will make a subtle
increase on Thursday, bringing increased coverage of dry
thunderstorms over Utah`s high terrain. Still, coverage is
expected to be isolated to widely scattered.

Moisture continues to increase through the late week and into the
weekend, bringing increased coverage of showers and thunderstorms
across Utah. With increasing lower level moisture, the potential
for wetting rains from individual storms will greatly increase. In
addition to the increasing chances for wetting rains, afternoon
relative humidity will also significantly improve throughout the
mountainous terrain while RH values in the lower elevation valleys
of western and eastern Utah will struggle to rise out of the
teens.

&&

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

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

WY...None.
&&

$$

PUBLIC...Webber
AVIATION...Traphagan
FIRE WEATHER...Webber

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