402
FXUS65 KSLC 152128
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
228 PM MST Sat Nov 15 2025

.SYNOPSIS...An active pattern will bring heavy rainfall to
southwestern Utah through Sunday, with moderate to heavy mountain
snow for the higher elevations of southern Utah. Additional
storms lurk next week in this active pattern, with the highest
chance for impactful snow accumulations across southern Utah.

&&

.SHORT TERM (Through 00Z Tuesday)...

Key Messages:

- Periods of moderate to heavy rain across southwest Utah begin
  tonight and persist into the day Sunday will result in rises on
  all area rivers, streams and normally dry washes. Flash flooding
  is possible in prone areas including slot canyons and near the
  Forsyth Burn Scar.

- Snow levels across southern Utah fall to near 7500 feet Sunday,
  with accumulations of 6-12" above 9000 feet Sunday through
  Monday.

- Valley rain/mountain snow spreads into central/northern Utah
  Sunday afternoon, with 2-5" of snow expected above 7500 feet.

An upper low spinning off the southern CA coast, accompanied by a
landfalling AR, is bringing widespread precipitation across much
of southern CA, southern NV and far western AZ this afternoon.
This is aided in part by a shortwave trough rotating around the
parent low and moving onshore across far southern CA this
afternoon.

This first shortwave currently lifting across far southern CA will
continue to lift north-northeast through tonight, allowing an arc
of precipitation to spread into southwest Utah later this evening
through tonight. Forecast PW values approaching 300% of normal
will bring the threat of heavy rain overnight across southwest
Utah, particularly in orographically favored areas such as the
Pine Valleys and Brian Head area. Rainfall rates at or above
0.25"/hour are likely with this band as it slowly lifts through
the region. This rainfall will result in rises on all area
rivers/streams, and dependent on intensity could result in areas
of flash flooding in prone areas including the Forsyth burn scar.

The main upper low will spread inland overnight before slowly
lifting through the Great Basin on Sunday. Another shortwave
rotating around this parent low will focus precipitation
initially across southern Utah Sunday morning, with precip lifting
into central and eventually northern Utah during the afternoon.
As colder air spreads into the region snow levels will fall to
near 7500 feet across southern Utah during the day Sunday. This
will help reduce runoff from additional precipitation through the
day, and represents the window of greatest snowfall accumulation
across southern Utah.

By Sunday evening the focus for valley rain/mountain snow will
have largely shifted into northern Utah, where snow accumulation
of 2-5" looks likely above 7000 feet. Further south, although the
better synoptic forcing will have moved away from the area, low
level southwest flow will maintain orographically induced precip
across southwest Utah, again focusing on the Pine Valleys and
areas around Brian Head. By the time precipitation winds down
Monday, snowfall totals of 6-12" look likely above 9000 feet
across southern Utah, with 2-6" of snow as low as 7500 feet. SWE
totals of 1-2" look likely across favored areas of southwest
Utah, and perhaps approaching 3" in the Pine Valleys by Monday.


.LONG TERM (After 00Z Tuesday)...The upcoming pattern remains
active, however a lot of uncertainty still exists regarding
details given that there will likely be cutoff lows impacting the
area during the longterm. Similar to the current cutoff that is
moving through the area this weekend, the next two cutoffs
continue to have significant variations in the run-to-run
guidance. The most certain aspects of this upcoming pattern is the
continuation of active weather and the lack of cold enough air
aloft to bring meaningful snowfall to valley floors. As for
everything else, such as QPF totals and timing/track of the storm,
those remain more uncertain given the limiting steering flow
aloft for these storms.

The first storm is currently scheduled to impact the area pretty
soon after this weekend storm exits the area. Ensemble members have
a better grasp on this storm relative to the following storm as ~80%
of members have this storm bringing QPF to most of the area with
preference towards more QPF across southern Utah. The window for
precipitation with this storm is late Monday-Wednesday. H7
temperatures have a relatively small spread with the 25th-75th
percentiles ranging from -4C to -8C (median of -6C). This favors
most precipitation staying as rain below 6,000 feet (potentially
even higher). Given that the airmass will modify as it slides down
the California coast there just isn`t a lot of cold air for it to
work with. With the increased cloud cover and the lack of warm air
aloft, valley inversions will be suppressed along with high
temperatures running near average across the north and potentially
up to 10 degrees below normal across far southern Utah if the
southern track materializes.

Guidance is more split on the following storm. ~60% of ensemble
members have another cutoff following a similar initial track as the
previous storm (down the California coast) before moving even
further south across southern Arizona into northern Mexico. This
track would keep some QPF possible across far southern Utah with
mostly dry conditions across the north. The other 40% of ensemble
members have the low staying offshore long before moving into
Mexico, resulting in dry conditions areawide.

All in all, a high degree of uncertain usually exists with these
types of cutoff systems so continue to check the forecast for
changes in the coming days. But the main message is valley rain and
mountain snow remain the most likely scenario with the best
opportunity for this to be across southern Utah Tuesday/Wednesday.

&&

.AVIATION...KSLC...Northwesterly flow will persist through
roughly 03-04z, when winds will gradually transition back to
southeasterly. Ceilings will gradually lower, producing mountain
obscuration as early as 10z with the arrival of isolated to
scattered rain showers. A wider swath of rain will begin after
17-18z with persistent southerly winds around 10-15kts.

.REST OF UTAH AND SOUTHWEST WYOMING...Isolated to scattered showers
will arrive into southwestern Utah by 00-01z this evening, slowly
overspreading across the state into northern Utah by 10-14z. Modest
VIS reductions are possible, though likely remaining VFR. A broader
swath of precipitation will develop first across southwest Utah
after 12z, pushing northeastward and reaching northern TAF sites by
17-20z. This will bring more persistent rainfall and the potential
for MVFR VIS/CIGs. KEVW could see IFR CIGs after 22z Sunday with a
transition to snow at the tail end of the precipitation after 03-06z
Monday or so. Finally, winds will increase out of the southwest by
Sunday afternoon, with locally enhanced winds possible near showers
across southwestern Utah, with gusts up to 30kts possible.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory from 11 PM this evening to 5 AM MST
     Monday for UTZ125.

WY...None.

&&

$$

SHORT TERM...Seaman
LONG TERM...Mahan
AVIATION...Cunningham

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