074
FXUS65 KSLC 061852
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1252 PM MDT Sun Sep 6 2026

.KEY MESSAGES...

- Gusty winds out of the southwest persist today across much of Utah
and southwest Wyoming, with an emphasis on areas west of I-15.

- Tropical moisture advects north into Utah today increasing chances
for precipitation.

- Threats for both flash flooding and isolated severe weather look
to develop across central and southern Utah this afternoon with the
arrival of tropical moisture.

- The active upper air pattern continues into next week (50-60%
chance), potentially resulting in more precipitation by mid-week
following an early week lull.


&&

.DISCUSSION...A large upper low continues to
slowly move east through the Pacific NW, deepening with eastern
extent. A tight southwest-northeast oriented pressure gradient
remains in place, tightest across western UT resulting in another
afternoon of enhanced southwesterly flow overhead. Most areas across
UT and SW WY can once again expect to see gusts in the 25-35mph
range, though areas west of I-15 may see gusts approach (and
potentially exceed) 45mph given stronger winds aloft with higher
surface temperatures to encourage stronger mixing.

This afternoon, moisture associated with Hurricane Marie will phase
into the mean upper flow as as the southern stream nudges north and
increases in magnitude. PWAT anomalies on the order of 0.5-0.8 above
seasonal normals (potentially exceeding 200% normal values) are
forecast to push north across much of Utah with this increase in
southwesterly flow. Currently, SPC MesoAnalysis suggests that PWATs
on the order of 0.8-1.2" of water have already begun to push into
southern UT. Widespread ascent will strengthen as the southern
stream phases into the mean flow with the aforementioned upper low,
with a quick eastern progression of the main precipitation axis
through the afternoon hours. As such, widespread showers and
thunderstorms are forecast to continue developing across central and
southern UT. Northern UT will also see precipitation this afternoon,
though it is more likely due to frontogenetical forcing ahead of
an incoming frontal boundary. Despite enhanced flow aloft
suggesting fast moving storms, robust moisture content within the
atmosphere continues to yield concern for flash flooding across
central and southern UT, where a slight risk (level 2/4) for
excessive rainfall has been outlined by the Weather Prediction
Center (WPC). Rainfall totals have decreased across CAM guidance,
suggesting lower rates with 0.3-0.5"/hr suggested on the higher
end. Despite this, some instances of flash flooding remain
expected given the anomalously moist airmass in place.

Regarding the severe threat, the forecast remains on track regarding
an isolated threat across far NW UT. Ample shear exists on the order
of 40-50kts ahead of the incoming frontal boundary, though only
modest buoyancy develops in the midst of lower surface temperatures
and drier air ahead of the front. The main hazards will be isolated
gusts to around 58mph and instances of sub-severe hail less than 1".

Come Monday and Tuesday, the upper low progresses east leaving the
forecast area in a dry westerly flow regime keeping conditions calm
to start the week. Regarding a return to a wetter pattern, ensemble
guidance has shifted the onset somewhat with roughly 50% of all
ensembles supporting moisture return in some capacity to UT around
the Thursday-Friday timeframe. Roughly 80% of all ensemble members
support moisture return, and subsequently precipitation by Saturday-
Sunday, though a notable shift has occurred within ensembles
muddying the forecast once again. This will be monitored and the
forecast will more than likely change as a result going forward
given low confidence.

&&

.AVIATION...

KSLC...VFR conditions will persist for the KSLC terminal through the
period. Gusty southerly winds will continue during the day with
clouds and moisture increasing this afternoon in the form of showers
and some isolated thunderstorms. Winds will weaken overnight before
a cold front moves through mid morning on Monday with a transition
to northerly winds.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist for
the entire airspace through the period. Stratiform rain will
continue across southern and central portions of the airspace with
embedded thunderstorms developing during the afternoon. Scattered
thunderstorms develop late afternoon across the northern terminals.
Winds remain strong out of the south before a cold front moves
through the northern airspace mid morning on Monday.

&&

.FIRE WEATHER...Moisture will continue to gradually increase this
afternoon as southwesterly flow pushes moisture further north.
This afternoon, expect locally critical fire weather conditions
primarily across the West Desert and Great Salt Lake Desert where
humidities have been observed dropping below 15%. Additionally,
strong wind gusts across areas primarily west of I-15 will range
from 30-45mph each afternoon into Sunday.

Today, a stronger push of moisture arrives to Utah with widespread
showers and thunderstorms across the state, though primarily across
central and southern Utah. The highest rainfall totals are expected
across higher terrain of central and southern Utah, though lower
elevation areas further east may see higher isolated totals from
stronger storms. For lower lying areas west of I-15, generally a
trace or less of precipitation is expected today. Thunderstorms
capable of wind gusts to around 50mph are possible across far
northwest UT this afternoon, and a few scattered gusts to 58mph
cannot be ruled out. A drying trend is expected to develop Monday
and Tuesday with more precipitation expected after midweek next week
across at least southern and central Utah.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Flood Watch until midnight MDT tonight for UTZ113-114-116>120-
     122-124>128.

WY...None.
&&

$$

PUBLIC...Worster
AVIATION...Mahan
FIRE WEATHER...Worster

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