984
FXUS65 KSLC 022142
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
342 PM MDT Wed Apr 2 2025

.SYNOPSIS...Troughing will maintain an unsettled pattern through
Friday. The pattern will gradually shift towards ridge dominated
moving into the upcoming week, resulting in dry and mild conditions.

&&

.SHORT TERM (Through 12Z/6AM Friday)...A large scale mid to upper
level trough remains centered more or less atop the area this
afternoon. Across the northern half of the forecast region,
steepened lapse rates due to increased cold air aloft is driving
the development of some instability driven showers. Further south
more into central Utah, the area is situated beneath something of
a deformation zone given the progression of the trough, which in
combination with instability is yielding showers with fairly
limited motion. As daytime heating ceases later this evening,
coverage of shower activity should begin to decrease in these
areas. Across southern Utah, nearer the base of the trough,
multiple shortwave impulses continue to ripple by within the
broader scale trough. Along with with some extra support from an
associated surface low, a higher coverage of shower activity
pivoting around the circulation is noted accordingly.

Through the remainder of the short term, the aforementioned
features will slowly continue an eastward trajectory. With the
pattern remaining fairly similar, albeit shifting slightly,
southern Utah will continue to see higher precipitation coverage.
In particular expect highest chances over the high terrain, with a
higher coverage period expected during the daytime due to diurnal
heating. Elsewhere across the forecast region, daytime heating
will also once again trigger development of scattered shower
activity.

Impacts-wise, given minimal change in forecast philosophy, opted
to maintain the ongoing Winter Weather Advisory covering the
southern Utah mountains. Amounts remain broadly in the 6-12"
range, with potential for locally higher amounts in places like
the Tushar Range. In any stronger bands of snow, or where the
terrain can add a favorable upslope component given how the low is
pivoting through, some periods of higher snowfall rates to an
inch or so an hour will be possible. Snow levels will follow a
diurnal trend, generally rising to around 4500-5000 ft MSL during
the day, and falling more around 3500-4000 ft MSL during the
overnight. As such, some lighter lower elevation accumulations
will be possible, especially across southern Utah where
coverage/forcing will remain highest. Elsewhere at areas
northward, any stronger diurnal cell with convective enhancement
could briefly result in moderate periods of graupel/snow/rain mix,
which could pose briefly hazardous to any motorists encountering
them.

.LONG TERM (AFTER 12Z FRIDAY)...The long term forecast period
features a general trend of drier and more stable conditions as high
pressure gradually builds into the area. Temperatures will trend
higher during this timeframe, eventually bringing temperatures back
to and above normals for this time of year.

However, this period begins Friday morning with an elongated trough
still over the area, with a closed low over Arizona. This will
maintain moist and unsettled conditions for Utah, with showers
increasing again Friday afternoon. Precipitation should remain
relatively light, with around 1-3 inches of snow over the mountains,
highest across southern and central Utah. With H7 temperatures
continuing to trend upward (to between -6 to -9C across the forecast
area), snow levels should be above 5-5.5kft most areas by afternoon.

As precipitation winds down Friday evening with the loss of daytime
heating, some locally gusty canyon winds will be possible. Areas of
focus include both the Wasatch Front and Washington County. At this
point, however, models are not in very good agreement with canyon
winds of any significant strength along the Wasatch Front, but with
a general east to northeasterly H7 flow and surface pressure
gradient, this is something to monitor. There is more agreement with
regards to gusty Washington County canyon winds, but even so, the
NBM currently only has less than a 20% chance of gusts reaching 45
mph.

High pressure building into the area from the northwest will then
bring drier and more stable conditions to the area on Saturday,
along with warmer temperatures (albeit still below normal). By
Sunday, the ridge axis will be over eastern Nevada with Utah
remaining under a northwesterly flow aloft. Temperatures should rise
closer to climatological normals on Sunday. However, a shortwave
trough is then forecast to break into the ridge. Mostly, this will
just flatten the ridge, halting the warming trend and bringing a bit
of an increase in moisture to the area. Some models are a bit
stronger with the trough, such as the deterministic GFS. This
solution would bring precipitation to at least northern Utah along
with a cooling trend for the Monday/Tuesday timeframe. For now, just
maintained the NBM in the forecast given model spread. By Wednesday,
a broader ridge will build into the area, leading to a more
prolonged period of dry and warm conditions (afternoon maxes over
70F likely at SLC Wed-Fri).

&&

.AVIATION...KSLC...Snow showers, primarily around nearby mountainous
terrain, will taper off around 01Z. There is around a 30% chance for
showers at KSLC, likely as a rain and snow mix capable of MVFR
conditions. Dry conditions will last through the night, although
mountain obscuration is likely. Isolated to scattered showers,
primarily mountain snow showers, will build after 18Z.

.REST OF UTAH AND SOUTHWEST WYOMING...Showers will primarily linger
around mountainous terrain for southwest Wyoming and northern Utah
through around 01Z. Throughout southern Utah, it is more likely for
precipitation to track into valley areas, including snow showers at
KCDC and KBCE and rain showers at KSGU through 09Z. Snow showers
will be capable of lowering conditions into MVFR or IFR range.
Isolated to scattered showers will build after 18Z for southwest
Wyoming and most of Utah, primarily around mountainous terrain.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory until 9 PM MDT Thursday for UTZ125.

WY...None.
&&

$$

SHORT TERM...Warthen
LONG TERM...Cheng
AVIATION...Wilson

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