924
FXUS65 KSLC 140946
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
346 AM MDT Wed May 14 2025

.SYNOPSIS...An unsettled pattern will persist with trailing impulses
behind a departing trough through the work week, and another
stronger broad trough expected over the weekend. Temperatures will
warm moving towards the weekend, cooling once more as the broader
weekend trough begins to move through.

&&

.SHORT TERM...Morning water vapor loop once again shows a slow
moving broad trough churning atop the forecast region. In addition
to helping maintain the cooler temperatures, broad synoptic
forcing is helping in the maintenance of scattered shower
activity. On a more mesoscale level, radar and satellite trends
appear to show some lake enhancement to activity shifting off the
Great Salt Lake and into adjacent locations across Davis and
northern Salt Lake County. Given the lowered freezing level and
convective nature to this activity, glancing into the parking lot
here at the forecast office actually shows some minor graupel
accumulation on cars.

Moving into the day Wednesday, the broad trough will continue a
very slow eastward progression. Subtle energy impulses will
continue to pivot through the cyclonic flow, and given steepened
lapse rates courtesy of the colder core of the low overhead,
daytime heating will help further contribute to destabilization.
With pockets of mean surface CAPE around 200-500 J/kg, will see
coverage of scattered showers and thunderstorms increase. Forecast
coverage appears to be highest across the northern half of the
area. Given decent saturation through the column, think impacts
wise convection is more likely to result in periods of moderate to
heavy rain, lightning, and some small graupel, though a few
modest wind gusts cant entirely be ruled out. Coverage will begin
to wane later on through the evening and into the overnight hours
as daytime heating ceases, though expect some amount of shower
activity to continue across the north, especially in the higher
terrain.

The broader scale trough will continue to shift east of the
region on Thursday, but a trailing wave will ripple through
overhead in its wake. Moisture and forcing with this will be
further favored across the northern half of Utah and into
southwest Wyoming, and corresponding precipitation chances will be
as well. Synoptic conditions will once again also favor some
modest destabilization through the day, especially along/east of
the northern high terrain, and as such expect to see a similar
diurnal pattern with an increase of shower/thunderstorm coverage
through the day. Afternoon highs will rebound several degrees from
that of Wednesday, though remain below climatological normal for
mid May.

.LONG TERM (After 12Z/6AM Friday)...Long term forecast begins with
an extremely subtle and transient shortwave ridge shifting
through overhead. This feature will help continue the gradual
warmup, though forecast afternoon highs remain near to slightly
below normal. This will partially be a result of a fair bit of
moisture and associated cloud cover beneath the ridge and ahead a
corresponding weak shortwave impulse quickly shifting in. Given
much of this moisture is also more mid/upper level in nature, and
that the synoptic forcing for ascent will be pretty modest, only
see some lower end (~20-40%) chances of scattered showers
generally along/north of the I-80 corridor. With some very modest
destabilization, a couple thunderstorms will also be a
possibility, particularly along/east of the northern high terrain.

Temperatures will continue to warm into Saturday as another
larger scale trough starts to dig into the Great Basin, and deep
southwesterly flow increases atop the local forecast region. In
comparison to the last system, H7 winds don`t look as strong, so
while wind gusts will pick up in the prefrontal environment,
current forecast carries gusts more in the 20-40 mph range at
areas roughly south of I-70. Lingering/increasing moisture will
also result in a continuation of fairly widespread cloud cover,
which will act to limit thermal mixing to an extent. That said,
will see shower activity increase through the day, and
precipitation will have potential to mix some of that momentum
downward and result in some corresponding gusts. Also appears
prefrontal moisture advection will likely remain more mid to upper
level in nature, and drier subcloud layers could yield some DCAPE
that any type of more convective cell could take advantage of.
May be something to monitor for those with wind related concerns
for recreation or outdoor events as we get closer.

Saturday night on into Sunday a cold front ahead of the trough
will shift in, followed by the broader scale trough. The broad
trough will then gradually translate eastward through early in the
upcoming week, with nebulous lobes of energy churning within it.
Precipitation chances will become much more widespread as the
front works in, and remain quite elevated as the trough remains
overhead given pretty decent deep layer moisture. Ensembles differ
on how quick the system and associated moisture start to lift
out, but general consensus appears to be in the mid Monday to
early Tuesday time range or so. Models generally show some
semblance of ridging building in after that, though uncertainty
increases and is pretty high by this point.

Impacts wise, it does look like this system could bring a decent
amount of water with it over the course of its few days in/near
the forecast region. Current forecast carries storm total
(Saturday morning to Monday night) water amounts with fairly
widespread 0.25" to 0.75" for most western valley locations (on
the lower side of that across SW UT, and on the higher side of
that along much of the Wasatch Front). Even at the NBM`s 25th
percentile, most of the forecast region picks up measurable
precipitation, and many with fairly measurable amounts. Given
NAEFS/ECM mean IVT near or above the 90th percentile
climatologically, the ECMWF Extreme Forecast Index unsurprisingly
highlights much of the area with climatologically anomalous QPF.
The mountains of Utah are no exception either, with fairly
widespread QPF/SWE in excess of 1.00", with some northern mountain
areas even in the 1.50" to 2.00" range. With cooler H7 temps and
lowered snow levels as the core of the trough is overhead, this
actually looks like it could translate to some pretty appreciable
late season snow accumulations roughly above 8500 feet or so. All
that said, will certainly be a system to keep an eye on in regards
to trends.

&&

.AVIATION...KSLC...Shower activity, scattered in nature, will
increase in coverage through the day given destabilization. Given
potential convective nature, around a 20-30% of thunderstorms is
noted. Gusty erratic winds would be possible with any convection
nearby. Otherwise, winds will generally trend westerly late
morning to early afternoon, slightly in favor of north of due
west. Conditions generally expected to remain VFR, though briefly
reduced conds possible in any heavier precip/convection.

.REST OF UTAH AND SOUTHWEST WYOMING...A broad scale trough will
remain the dominant forecast influence through the TAF period.
Showers, generally scattered in nature, will increase in coverage
through the day given daytime heating. Coverage is expected to be
highest across northern terminals. Given modest destabilization,
around a 20-30% chance of thunderstorms is noted. Given the
pressure gradient, most terminals will see winds favor a bit more
of a west to northwesterly directional component during the day.
VFR conditions generally expected as a whole, though brief
categorical reductions will be possible in any heavier showers or
thunderstorms.

&&

.FIRE WEATHER...Modest instability behind a cold front will lead to
widely scattered showers and thunderstorms across the state
through Wednesday afternoon. Afternoon shower and thunderstorm
chances favor northern Utah on Thursday and Friday, as
northwesterly flow cuts off additional moisture availability
across the southern portion of the state. Poor overnight humidity
recoveries are expected across far southern Utah Thursday night
into Saturday morning as a result. A trough deepens into the Great
Basin on Saturday, yielding increased moist, southwesterly flow
across the region which will bring brief period of stronger
southwesterly winds on Saturday across southern portions of the
state. Chances for widespread wetting rains increase late
Saturday, continuing through the remainder of the weekend into
early next week.

&&

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

$$

SHORT TERM...Warthen
LONG TERM...Warthen
AVIATION...Warthen
FIRE WEATHER...Whitlam

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