672
FXUS65 KSLC 220006
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
606 PM MDT Mon Sep 21 2026

.KEY MESSAGES, Issued 130 PM MDT Mon Sep 21 2026...



- Moisture is pushing into southwestern Utah and will continue to
  gradually shift north and east with convection developing across
  central and northern Utah on Tuesday.

- Moisture remains elevated across the Four Corners through the
  week which will keep diurnal convection possible across
  southeastern Utah with dry conditions elsewhere in Utah.


&&

.DISCUSSION, Issued 130 PM MDT Mon Sep 21 2026...
Moisture is starting to push into the southwestern
portions of Utah with reflectivity on radar, however this rain is
struggling to make it to the surface. RH across these areas are
between 20% (lower elevation) up to 60% across the higher
elevations. It will take a bit for the PBL to moisten, especially
given the light rainfall rates. This activity is thanks to an
upper level low that is currently centered over central
California. This low will continue to move east with precipitation
developing across eastern Nevada and western Utah this afternoon
and evening.

This activity shifts into central and northern Utah on Tuesday
with morning showers transitioning to afternoon thunderstorms.
There will be plenty of shear (40+ kts) and steep lapse rates,
although the CAPE will be marginal. This will favor quasi-linear
storms that will be capable of producing gusty winds for areas
near and east of the Wasatch and in Castle country. The storm
motion with these will be rather fast, so that will limit the
threat of any flash flooding to areas that are highly sensitive or
areas where training thunderstorms occur.

This low pushes out of the area by Wednesday with a return to
near seasonal temperatures and dry/stable conditions. The one
exception will be across eastern and southeastern Utah as moisture
remains elevated.


&&

.AVIATION...

KSLC...Light northwesterly winds transition to southeasterly after
04z. Moisture increasing from the south will yield increasing clouds
overnight with a 30% chance for showers to impact the terminal
between 06-12z, with minimal operational impacts outside of variable
winds. Additional shower activity is possible through the afternoon
before chances for thunderstorms increase after 20z. Storms tomorrow
afternoon will be capable of producing heavy rainfall and gusty and
erratic outflow winds in excess of 35 kts.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions prevail overall
for all regional terminals into Tuesday morning. Winds remain
generally light and diurnally driven across northern Utah into
Tuesday, while gusty southwesterly winds develop across southwest
Utah Tuesday afternoon. Shower activity currently ongoing across
southwest Utah will continue to spread northward through the evening
and overnight, with showers impacting most northern Utah and
southwest Wyoming terminals through Tuesday afternoon. Thunderstorms
are expected to develop mainly across the northeastern portion of
the airspace after roughly 20-21z, with potential to produce gusty
and erratic outflow winds in excess of 40 kts and heavy rainfall
that could drop VIS to MVFR/IFR at times.

&&

.FIRE WEATHER, Issued 130 PM MDT Mon Sep 21 2026...
An area of low pressure is moving into the Great Basin. This
is bringing an increase in cloud cover and showers to
southwestern Utah. This activity will gradually shift north and
east overnight with showers and thunderstorms developing across
central and northern Utah on Tuesday. These storms on Tuesday will
be capable of producing gusty and erratic winds along with
frequent lightning, small hail, and brief heavy rain.

This activity moves out of Utah on Wednesday, but moisture will
remain elevated across the Four Corners with diurnal convection
possible across southeastern portions of Utah, but confidence in
details remain low on these storms. The heaviest precipitation
looks to remain across New Mexico and Colorado. Otherwise, winds
will remain light and diurnally driven through the week with near
normal temperatures.

&&

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

$$

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

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