472
FXUS65 KSLC 281531
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
931 AM MDT Tue May 28 2024

.UPDATE...Updated forecast for aviation discussion. Otherwise,
previous forecast looks on track with no changes necessitated at
this time.

&&

.SYNOPSIS...High pressure will be in place today bringing high
temperatures of 5F to 10F above normal. A cold front Wednesday
will bring a few showers and thunderstorms with a gusty wind
threat. Temperatures will cool back down to around normal by
Thursday behind the front. Another warming trend will begin in
earnest by early next week.

&&

.SHORT TERM (Through 12Z/6AM Thursday), Issued 404 AM MDT...Early
Tuesday morning analysis products depicted a mid-level ridge axis
centered over eastern Utah while an area of low pressure was
approaching the British Colombian coastline. The ridge will move
off to the east today while the low approaches the Washington
coast. As a result, modest deep-layer SW flow will overspread Utah
and SW Wyoming, promoting a continued warming trend (highs 5F to
10F above normal) while also opening the door to modest mid-level
moist advection. Just enough moisture will be introduced to foster
isolated shower and thunderstorm development this afternoon,
mainly over high terrain areas of northern and central Utah.
Modest deep-layer shear development by late afternoon and early
evening could support updrafts that can briefly survive the trek
off of the terrain. Main hazards with this activity will be
isolated lightning and gusty winds in the 35-45 mph range.
Convective activity will be more robust and widespread on
Wednesday, however.

On Wendesday, models are in good agreement with their depictions
of the above-mentioned cold front moving across northern Utah and
SW Wyoming during the afternoon, before settling across central
Utah during the evening and overnight hours before diminishing.
Thanks to continued mid-level moisture advection and large-scale
ascent associated with the front, scattered showers with isolated
thunderstorms will break out across northern Utah during the late
morning and afternoon hours, with additional convective initiation
gradually trending southward into central Utah during the
evening. Ensemble mean SBCAPE values reach 1000J/Kg during the
late afternoon and early evening, with superimposed deep-layer
shear values in the 30-40kt range. These ingredients suggests the
environment will be supportive of organized updrafts and
propagating cold pools. Available ingredients are the best we`ve
seen so far in what`s otherwise been a relatively quiet Spring in
terms of convective activity. Main threats will once again be
lightning and gusty outflow winds, with the coverage and strength
of winds much greater than Tuesday, with numerous gusts in the
45-55 mph range accompanying many of the showers and storms,
thanks to a dry sub-cloud environment and increasing kinematics
aloft with the approaching frontal boundary. HREF max wind gust
plots exceed 58 mph across portions of central Utah during the
late afternoon and early evening hours (with a 10% probability
contour appearing), focused between Provo and Cove Fort.
Convection will gradually wane during the evening hours, but
enough support owing to the presence of the cold front will be in
place to support a few showers through the night, particularly
across northern and central Utah.

.LONG TERM (After 12Z/6AM Thursday), Issued 404 AM MDT...Thursday
will begin a modest temperature drop in the wake of a cold front
Wednesday. But for the end of May, temperatures are forecast to be
very seasonal and very pleasant. The weather pattern headed into
and through the weekend look to bring rather mild conditions to
the region. Warming temperatures are forecast as southwest flow
arrives by Saturday with high temperatures near the triple digit
marker in St. George and in southeast Utah. High pressure is not
expected to leave the region anytime in this long term forecast.
In fact, there`s little variance in ensemble models until next
week, where the question becomes, just how high will temperatures
climb with a building ridge?


&&

.AVIATION...KSLC...Predominantly VFR conditions expected through the
period with generally light winds following typical daily trends.
Afternoon cumulus development over the Oquirrhs will likely
eventually lead to a thunderstorm or two with bases at or above 10k
feet AGL moving northeastward into the Salt Lake Valley. Such storms
will have 50% chance of gusty outflow winds reaching the terminal
from about 21Z-0Z, though with only a 10-20% chance of reaching the
terminal vicinity itself. Showers/thunderstorms are possible again
tomorrow (30% chance).

.REST OF UTAH AND SOUTHWEST WYOMING...Isolated showers/thunderstorms
are expected this afternoon, generally east of I-15 and north I-70,
tracking northeastward. Such storms will be capable of gusty winds.
Outside of this, VFR conditions and light diurnal wind variations
are forecast today and tonight.

&&

.FIRE WEATHER, Issued 404 AM MDT...Warm, dry conditions will be
in place today with temperatures around 10F above normal.
Increasing mid-level moisture ahead of an approaching cold front
will promote isolated high-based showers and storms across
northern and central Utah`s high terrain areas this afternoon and
evening. On Wednesday, the cold front will move through northern
Utah during the afternoon, before dropping into central Utah by
Wednesday evening. The front will promote the development of high-
based showers and storms across northern and central Utah, with
the greatest coverage during the afternoon and evening hours.
Showers and storms will be capable of strong, gusty and erratic
outflow winds. Temperatures will cool 10-15F across northern and
central Utah behind the front on Tuesday. As we get into the
weekend, warm, dry conditions will return to the state with
temperatures increasing to near 10F above normal once again.
Through the next week, little change is expected across southern
Utah, with temperatures remaining 5-10F above normal along with a
continuation of dry conditions accompanied by poor overnight
recovery.

&&

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

$$

Warthen/ADeSmet/NDeSmet/Van Cleave

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