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Area Forecast Discussion
Issued by NWS Salt Lake City, UT
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FXUS65 KSLC 182209
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
409 PM MDT Thu Apr 18 2024

.SYNOPSIS...Mostly dry conditions are expected to persist over
Utah and southwest Wyoming over the next several days. High
pressure will build in by the weekend, bringing a noticeable
warming trend.

&&

.SHORT TERM (Through 12Z/6AM Saturday)...
A stalled frontal boundary across central Utah continues to
bifurcate the state between slightly below normal temperatures
across northern Utah and slightly above normal temperatures across
southern Utah. North of the boundary, the pressure gradient is
maintaining light northerly winds, while south of the boundary
southern Utah continues to see southwesterly winds.

Quiescent conditions continue tonight with lighter winds
overnight. On Friday, there will be a weak/decaying mid-level
trough moving across the desert southwest. The small amount of
moisture increase and interaction with the stalled front will
increase clouds over central Utah and invigorate some
isolated/scattered showers central Utah along the frontal
boundary. Northern Utah will remain dry and below normal north of
the front, while far southern Utah remains mostly dry and above
normal south of the front.

.LONG TERM (After 12Z/6AM Saturday)...
Big picture of the extended forecast period trends from a largely
dry and warming regime through roughly the mid-week period to a
wetter and cooler regime toward the end of the week. Weak high
pressure leading up to the weekend will be replaced by a weak area
of low pressure through the weekend. That said, the mid-level
flow pattern will continue to feature above normal heights which
will help to favor warmer temperatures over the weekend. With the
introduction of a weak area of low pressure and limited lower
level moisture, there will be a low end chance (~10- 20%) of light
precipitation (generally less than 0.05 inches liquid) over
portions of central and southern Utah, mostly favoring the
mountainous terrain and adjacent valley areas.

Ensemble guidance is in good agreement of a mean ridge remaining the
dominant large scale feature over the forecast area through at least
Monday night/ Tuesday morning, which will keep drier and warmer
conditions in the forecast through this period. There is some
deterministic guidance that drops a weak frontal boundary into
northern UT overnight Sunday into Monday which would cause about a
10 degree drop in daytime high temperatures, but daytime highs will
still remain right around seasonal normals across northern Utah and
southwest Wyoming, and about 10-15 degrees above normal for the
southern half of Utah. Past Tuesday morning, there is increasing
confidence that the broad-scale weather regime will begin
transitioning from a mean ridge to a mean trough. Chance for
precipitation will lag into the latter half of the week as
southwesterly flow aloft creates a drier low level environment,
however, models are favoring an offshore trough progressing inland
later in the week which would introduce much more lift and moisture
into the area. So while there is still some uncertainty in exactly
when we`ll start to see that moisture phase into the area, we have
generally high confidence that the pattern will flip to a regime
favoring increased moisture and cooler conditions across the region.
At this point in time, we are not expecting anything any incredibly
impactful system, however, the European ensemble suite supports a
system that is just a bit wetter and windier than what`s typical for
this time of year. Will continue to monitor trends in the guidance
heading forward as this pattern will, once again, put a hold on
those nicer spring-time conditions.


&&

.AVIATION...KSLC...VFR conditions will persist through the TAF
period. Northerly winds will mostly dominate through the TAF
period, although early Friday morning (likely 12Z-16Z) winds will
become light/variable before returning to northerly for the
remainder of the day.

.REST OF UTAH AND SOUTHWEST WYOMING...A dry stationary front will
remain place across central Utah through the TAF period. South of
the boundary, southern Utah will maintain southwesterly winds
while north of the boundary expect mainly northerly component
winds to dominate. On Friday, a few isolated/scattered showers
will develop along the frontal boundary over central Utah, with
dry conditions north/south.

&&

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

$$

SHORT TERM...Church
LONG TERM...Webber
AVIATION...Church

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