009
FXUS65 KSLC 122201
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
401 PM MDT Sun Oct 12 2025

.SYNOPSIS...Moisture increases across the eastern area tomorrow as
our next storm system begins to take shape over the western U.S.
This next storm system will impact the area during the middle
part of the week, with cooler temperatures prevailing through late
week.

&&

.DISCUSSION...While today has marked a lull in active weather, our
storm system is beginning to take shape as a trough is already
beginning to dig along the PacNW coast and is set to begin
bringing a change in the weather starting early Monday. This next
storm system is expected to bring impacts through at least
Wednesday, but potentially as late as Thursday evening.

Key Messages:

- Another shot of potentially widespread precipitation is likely
  (70-80% chance) across the northern half of Utah, with about a
  30-40% chance that rainfall totals eclipse 1 inch for a portion
  of the Wasatch Front. Additionally, high elevation snowfall
  appears likely for elevations above 7,000ft.

- Strong southerly winds will spread across the western half of
  the area on Monday, expanding into the eastern half of the area
  on Tuesday. Current model guidance supports afternoon wind gusts
  between 35-45 mph across the western half the area on Monday and
  Tuesday, and upwards of 30-35 mph across the eastern area on
  Tuesday.

- Another stout cold front is expected to push through the
  forecast area late Tuesday through Wednesday. Temperatures will
  drop back to below normal, introducing potential threat of
  freezing temperatures for areas with unharvested crops.

As mentioned above, our next storm system is already beginning to
take shape upstream as a trough deepens offshore of the PacNW
region. Through the early morning on Monday, winds through the
atmosphere will transition to a southerly flow, helping to
increase lower level moisture (primarily across the eastern half
of the area). As such, will see chances for precipitation increase
early in the morning across eastern Utah. While nowhere near as
significant as our previous moisture surge, PWAT values will
increase to upwards of 150-200% of normal for this time of year,
especially across the eastern half of Utah. Though the greatest
coverage of storms is anticipated across the eastern periphery of
our forecast area, isolated storms forming over terrain features
between the Green River and central Utah mountains will carry
potential for heavy rainfall. As such, flash flooding will remain
possible during the daytime hours for most areas across southern/
central Utah. A shortwave disturbance is expected to lift
northward Monday evening, bringing an increase in shower/
thunderstorm potential primarily across the eastern half of Utah/
southwest Wyoming.

In addition to the increased moisture potential, strong southerly
winds are expected to develop Monday afternoon across the western
half of Utah and south of the I-80 corridor. For these areas, wind
gusts will likely range from 30-35 mph during the afternoon
hours, with less than 10-15% chance of gusts exceeding 45 mph. On
Tuesday, a slight uptick in speeds should be expected across this
same area (gusts 35-40 mph) with an upwards of 20% chance of wind
gusts exceeding 45 mph over main transportation routes (i.e.
US-6/US-50). Stronger southerly winds will also expand into
eastern Utah on Tuesday, however, wind gusts will remain below
35-40 mph.

This whole storm system moves inland from late Tuesday through
Wednesday, introducing another cold front into Utah and southwest
Wyoming. The strong lift produced by the trough as a whole will
help to kick off a band of light to moderate precipitation that
will be most favored for areas (roughly) north of Nephi, though
model output shows potential for this line of precipitation to
extend as far south as Cedar City. There is a generally low to
medium chance that this line produces heavy precipitation that
would favor total accumulation amounts of over 1 inch for a
portion of the central and northern Wasatch Front (30-40% chance).
Will need to monitor trends in the models moving forward,
especially as high-resolution guidance comes into the mix. Just
know the potential will be there again.

After Wednesday, models begin to struggle with how quickly this
storm system will depart the region. If it departs quickly
(supported by 20-40% of the model guidance), then conditions will
begin to stabilize and dry out by Friday. The slightly favored
scenario is that the northern stream remains active over the PacNW
(60% probability) which would keep at least the norther third of
Utah/ southwest Wyoming in an active, cooler and wetter pattern
through at least Saturday.

&&

.AVIATION...KSLC...VFR conditions to continue at the terminal
through the TAF period. Generally light northwesterly winds prevail
this afternoon before transitioning to the southeast around 04z.
Increased southerly winds with gusts 15-18 kts are expected to
develop after 18z Monday.

.REST OF UTAH AND SOUTHWEST WYOMING...Dry conditions across the
airspace will yield continued VFR conditions at all regional
terminals today. Skies remain generally clear areawide, though
patchy fog development is possible at high valley terminals such as
KLGU-KEVW-KHCR between 9-14z Monday morning. Otherwise, expect
generally light and terrain-driven winds.


&&

.FIRE WEATHER...After a day a drying alongside high pressure, moisture will
begin to increase once again on Monday as our next storm system
begins to take shape across the western U.S. On Monday, deeper
southerly flow will be introduced into the region as an upstream
low pressure system begins deepening, helping to bring an increase
in lower level moisture (particularly across the eastern half of
Utah) through the morning hours. That said, little, if any,
moisture increase will be seen across the western half of Utah. In
addition to the changes in moisture, this deep storm system will
bring a notable increase in wind speeds from Monday afternoon
through Tuesday. At first, the threat of stronger winds will be
confined to areas along and west of the I-15 corridor on Monday,
then expand into eastern Utah on Tuesday. For the western half,
wind gusts are expected to fall between 30-40 mph on Monday, then
increase to 35-45 mph on Tuesday. For both Monday and Tuesday,
western Utah will see isolated pockets of afternoon min RH between
20-25 percent, raising concern for elevated fire weather
conditions. For the eastern half, gusts between 30-35 mph are only
expected on Tuesday, but will be paired with higher relative
humidity.

By Tuesday evening, the aforementioned low pressure system will
shift inland and bring another round of potentially widespread
precipitation across Utah. The highest likelihood of wetting rains
will be confined to the northern half of Utah, decreasing south
of the I-70/US-6 corridor. Through the remainder of the week, low
pressure is anticipated to dominate the region, promoting chances
for precipitation (mainly across the northern area), cooler
temperatures, and higher humidity.

&&

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

$$

PUBLIC...Webber
AVIATION...Whitlam
FIRE WEATHER...Webber

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http://weather.gov/saltlakecity