390
FXUS65 KSLC 242149
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
349 PM MDT Mon Jun 24 2024

.SYNOPSIS...Hot and dry conditions will continue across northern
Utah...with showers and thunderstorms continuing across southern
and eastern Utah through Tuesday. By Wednesday, a more widespread
threat of showers and thunderstorms can be expected.

&&

.SHORT TERM (Through 12Z Wednesday)...This afternoon a gradient in
moisture remains in place across southern/central Utah with PW
values approaching an inch near the UT/AZ border. In addition,
mesoanalysis shows up to 1000 J/kg of CAPE into southwest Utah.
Surface moisture remains decent through this region, with dew
points largely in the mid 40s with some pockets near 50. This
environment is marginally conducive to flash flooding, mainly
where any storms can train or redevelop upstream. So far one cell
over the upper Escalante Basin has tapped into this environment.
Over time this evening, the threat for any isolated flash flood
will transition toward the AZ border as outflows from convection
over the upper Escalante Staircase work down toward the border,
and interact with the remaining instability.

Farther north across northern Utah, much drier and hot conditions
remain in place. A very localized gusty wind threat is possible
from any decaying showers on the northern periphery of the
moisture up through Juab to Utah to Summit Counties through early
this evening. Otherwise, the continued hot daytime temperatures
and poor overnight recoveries (with lows briefly touching the mid
70s early in the morning hours) continues to support a major
HeatRisk across much of the Wasatch Front corridor. Temperatures
will even climb a degree or two into Tuesday. Thus heat headlines
across northern and central Utah run through Tuesday evening.

On Tuesday the environment changes little, continuing to support
afternoon scattered shower and thunderstorm development across
southern and portions of central Utah. Isolated flash flood threat
will once again be the main concern across southern Utah.

.LONG TERM (After 12Z Wednesday), Issued 441 AM MDT...
High pressure centered over New Mexico will position our CWA in a
moist southwesterly flow. This moisture will advect into the
entire region by Wednesday with PWATs approaching record levels.
PWATs Wednesday and Thursday are forecast to be >1" across most of
the state with values approaching 1.3" across southern Utah. This
moisture will pair with a trough moving in from the PNW to create
scattered thunderstorms Wednesday and Thursday. Temperatures
remain elevated with a brief cool down on Friday.

Wednesday`s convection will be driven moreso by a shortwave out
ahead of the main trough. Given the elevated moisture profiles,
storms that do form will be capable of producing flash flooding in
flood prone areas. Some guidance keeps precipitation going in
parts of the CWA overnight Wednesday into Thursday. Lingering
cloud cover/precipitation on Thursday may influence convective
initiation timing and intensity on Thursday afternoon. By Thursday
the main trough will be moving by to our north with enhanced CAPE
and shear profiles along with greater synoptic forcing. These
parameters will increase the risk for strong to severe storms on
Thursday, depending on the amount of clearing we see in the
morning/early afternoon. The air mass moving in behind the trough
will be much drier and cooler, however the southern extent of this
air mass will be limited with less of a cool down across southern
Utah. Areas across northern Utah will see temperatures cool
closer to normal with the passage of this trough.

Friday will be the coolest day of the long term period as ridging
builds back in by the weekend with temperatures warming back to
the mid 90s for most valleys and mid 100s for southern Utah along
with mostly dry conditions. However, this appears to be short
lived as most of the guidance brings another PNW trough through
the region early next week. 36% of guidance has a deeper/faster
moving trough whereas the remaining guidance is a more shallow
trough that is further to our west on Monday.

&&

.AVIATION....KSLC...Minimal operational concerns are forecast for
the KSLC terminal through the valid TAF period. Winds will follow
diurnally driven trends, with light northerly winds reverting to
a southerly drainage flow around 04Z this evening.

.REST OF UTAH AND SOUTHWEST WYOMING...Afternoon showers and
thunderstorms will continue across southern and central Utah through
the remainder of the daylight hours. Areas near passing storms may
experience gusty and erratic outflow winds in excess of 30-35 mph.
After sundown, showers will diminish and flows will follow light
diurnal driven trends. Another day of showers and thunderstorms will
resume tomorrow afternoon, bringing similar threats of gusty and
erratic outflow winds.

&&

.FIRE WEATHER...
An anomalously moist airmass for June remains in place across
southern Utah today and Tuesday maintaining daily shower and
thunderstorm chances. The environment is favorable for storms
capable of locally heavy rainfall and isolated flash flooding.
However, much drier and hotter conditions remain in place across
northern Utah through Tuesday, where various heat headlines remain
in place.

By Wednesday an upstream trough will start to interact with the
airmass in place, pulling the moisture farther north into northern
Utah and bringing more widespread shower and thunderstorm
activity across the state. By Thursday, dry southwesterly flow
will start to nose into the southwest corner of the state, as the
best moisture starts to shunt eastward. However, this will likely
feature yet one more day of showers and thunderstorms, favoring
more the eastern half of Utah.

For Friday into the weekend another Pacific trough will nose in
to our northwest ushering in drier southwesterly flow across the
area, along with a slight cool down across northern Utah. However,
the main effect will be a warming and drying trend through the
weekend with breezy southwesterly winds. Chances for critical fire
weather conditions will likely stay confined to southwestern Utah
on Friday, more of western Utah by Saturday and most of the state
by Sunday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Excessive Heat Warning until 11 PM MDT Tuesday for UTZ101-
     104>106-116.

     Heat Advisory until 11 PM MDT Tuesday for UTZ102-103-107-118-119.

WY...None.
&&

$$

SHORT TERM...Church
LONG TERM...Mahan
AVIATION...Webber
FIRE WEATHER...Church

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http://weather.gov/saltlakecity