373
FXUS65 KSLC 282102
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
302 PM MDT Mon Apr 28 2025
.SYNOPSIS...The pattern will remain fairly unsettled over the
upcoming week, with some precipitation potential most days. A
cold front will knock temperatures down Wednesday, with a warming
trend then taking place Thursday into the start of the weekend.
&&
.SHORT TERM (Through 12Z/6AM Wednesday)...Another afternoon dealing
with a broad cutoff low, with current satellite loop showing the
center of circulation shifting southeast away from Milford. KICX
radar also shows a similar pattern to how precipitation is
wrapping/translating along with the low, with coverage highest
along and just south/east of the center. The stronger moist flow
into the terrain has helped result in some occasional bursts of
moderate to even heavy snow at higher elevations, with snowfall
rates of 1-2" per hour noted briefly at Clear Creek Summit earlier
in the day. Elsewhere across Utah and southwest Wyoming, activity
is more scattered in nature, with a slight uptick in showers
through the afternoon with the increase in diurnal heating and
associated low end destabilization. Activity will gradually
decrease from late evening on through the overnight hours as
daytime heating ceases, the low begins to advance further out of
the region, and dry air and subsidence in turn increase.
A weak transient shortwave ridge will brush through the region
Tuesday into Tuesday evening. Warming H7 temperatures will result
in a corresponding nudge upward in afternoon temperatures, with
high marks forecast to generally be pretty close to climatological
normal. As such, generally expecting mid/upper 50s across
southwest Wyoming, mid/upper 60s across the Wasatch Front and most
other lower elevation valleys, and 70s across far southern Utah.
While the ridge will provide a little boost to subsidence as it
builds in, there looks to be just enough forcing/moisture left
from the still departing cutoff low to yield isolated terrain
initiated shower activity. Per usual, these showers will trend
downward in coverage and intensity as heating ceases following
sunset. However, the ridge will begin shifting out of the region
through the night in advance of another upstream shortwave trough,
which will start pushing a cold front southward into northern
Utah in the predawn hours Wednesday morning. Will see precip
chances increase accordingly as this boundary pushes in.
.LONG TERM (After 12Z/6AM Wednesday)...On Wednesday, a trough will
be making its way across the northern Great Basin, gradually
splitting into a weak closed low well to our southwest as the parent
trough moves across northern Utah. Despite overall weak dynamics, a
band of showers will develop along/just behind the cold front within
an area of increased moisture. This band will cross northern Utah
during the morning, gradually slowing and weakening as it reaches
southern Utah by late evening. Thunderstorms will be possible,
especially during the afternoon with daytime heating.
Thursday and Friday will feature afternoon showers and thunderstorms
across southern Utah given some influence from the weak closed low
as it meanders across the area late in the work week. Drier
conditions are expected across northern Utah, with clear skies and
warming temperatures.
By Saturday, warm, southerly winds will begin to increase across the
entire area ahead of a highly amplified longwave trough along the
West Coast. Afternoon convection is looking more likely statewide,
given gradually increasing moisture and dynamics. This trough is
then likely to close off into a strong closed low over southern CA,
though there is still some question as to when and exactly where
this low tracks. As this low approaches and crosses our area (or
potentially just to our south), strong cold-air advection and
widespread valley rain and mountain snow will prevail. As an
example, current NBM high temperatures across the area will drop by
around 20-25 degrees between Saturday and Sunday, with 700-mb
temperatures reaching down to -4C to -8C across southern Utah (-2C
to -6C across northern Utah). As for precipitation, there still
remains plenty of spread in QPF thanks to uncertainties to the
synoptic pattern and moisture availability.
To summarize the weekend system, the main concerns we are watching
out for are 1) mountain snow accumulations, 2) southerly winds
approaching advisory level on Saturday, and 3) thunderstorm
potential, particularly on Saturday and Sunday afternoons.
&&
.AVIATION...KSLC...VFR conditions will prevail through the TAF
period. North-northwesterly winds will persist ahead of a southerly
shift around 05z. Around 18z, expect winds to shift to northwesterly
once again.
.REST OF UTAH AND SOUTHWEST WYOMING...Occasional MVFR CIGs will
continue at KBCE through at least 00z with snow showers perhaps
reducing vsbys periodically. Additionally, light rain is possible at
our southern Utah sites and extreme northern Utah sites through the
afternoon. Otherwise, VFR conditions will prevail through the
majority of the period.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&
$$
SHORT TERM...Warthen
LONG TERM...Cunningham
AVIATION...Worster
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity
