056
FXUS65 KSLC 212038
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
238 PM MDT Fri Mar 21 2025

.SYNOPSIS...A weak area of high pressure will move east of the
area today, as the next storm system spreads into the region
tonight through Saturday. A strong area of high pressure will
build across the region through the duration of next week bringing
a substantial warming trend.

&&

.DISCUSSION...Early afternoon upper air analysis indicates near
zonal flow across the Interior West. A 140kt+ jet max is nudging
into the PACNW. Integrated water vapor analysis indicates 95-99th
percentile values shifting east from the northern
California/Oregon Coast, representative of a landfalling
atmospheric river.

Both of these features, the jet max and the decaying inland
penetrating atmospheric river, will bring a period of moderate to
heavy mountain snow to the northern Utah mountains this evening
into Saturday morning. As the jet max passes overhead, the best
jet dynamics will cross northern Utah coincident with IVT values
in excess of 90th percentile. While flow will be initially
southwest near midnight, expect a general shift to west to west-
northwest.

While snow levels will initially start around 6000 feet, snow
levels will rise to around 6500 feet by early Saturday morning.
With snow levels, this high, any impacts will be constrained to
the higher terrain.

Winter weather advisories remain in effect for the northern
mountains, with a general 5 to 10 inches expected, locally up to
15 inches or so for the Bear River Range and the upper
Cottonwoods. Those with plans to head up the Cottonwood Canyons
this morning or across Logan Summit should be prepared for road
snow and possible traction restrictions. Blowing and drifting snow
may reduce visibilities at times for the Logan Summit area.

In the wake of this system, stout high pressure will build into
the region. Expect temperatures to gradually warm through the
week, reaching the mid to upper 70s across the Wasatch Front by
Wednesday.

Ensemble systems suggest another western trough will develop later
next week, bringing the threat of gusty winds ahead of a cold
front Thursday afternoon into Thursday evening, with a significant
cool down for Friday. Something to monitor at this time.

&&

.AVIATION...KSLC... A gradual shift to northwesterly is
currently occurring due to diurnal winds with winds shifting back
to southerly around 00-02z. Additionally, ceilings will begin
lowering around 02z with mountain obscurations likely and with
MVFR CIGs building in by 06z with -RA. Conditions will improve to
VFR with VCSH around 15z, though mountain obscurations through the
period will persist.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions continue
across all sites before MVFR CIGs occur across all northern sites
later this evening with IFR possible at KEVW. Additionally, all
northern sites will experience VCSH/-RA with higher elevation
sites seeing - SHSN. Conditions are expected to improve later
tomorrow afternoon.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory from 8 PM this evening to 4 PM MDT
     Saturday for UTZ110>113.

WY...None.
&&

$$

Kruse/Worster

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