495
FXUS65 KSLC 081001
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
401 AM MDT Sat Jun 8 2024

.SYNOPSIS...High pressure will build into the area today before
another weak disturbance grazes northern Utah late tomorrow into
Monday. Lingering moisture will maintain showers and thunderstorms
across portions of the area into Monday before drier air spreads
into the area.

&&

.SHORT TERM (THROUGH 12Z MONDAY)...The shortwave trough that brought
the showers and thunderstorms yesterday is now exiting east into
Wyoming, with what`s left of the showers continuing to diminish.
High pressure building into the area today will bring a more
subsident airmass, but daytime heating is expected to result in
enough instability to fire up isolated to scattered showers and
thunderstorms this afternoon given lingering moisture. While PWATs
are forecast to be lower compared to yesterday, the forecast of
~0.65-0.9 inches across northern and central Utah should be
sufficient to support those showers, although precipitation amounts
should be a bit less.

Temperatures will remain on the hot side, though some sites will
trend slightly cooler compared to yesterday. For the lower valleys
of far southern Utah, an Excessive Heat Warning remains in effect
through this evening. Although HeatRisk guidance has lowered, there
are still some localized areas in these zones which are being
highlighted by the guidance.

The ridge will quickly shift east of the area by tomorrow afternoon
as the next trough enters the West Coast states, grazing northern
Utah late tomorrow into Monday morning. Southerly flow will increase
ahead of this trough, and expect to see showers and thunderstorms to
develop again. With drier air working into west-central and
southwest Utah, showers and thunderstorms on Sunday will likely be
focused near the Idaho border, across the northern and central
mountains, and adjacent valleys to their east. Given better dynamic
support, some of these thunderstorms will trend stronger again,
particularly near the Idaho border, with wind and small hail being
potential threats. Otherwise, temperatures will trend warmer again
across the north while cooling across the south.

.LONG TERM (After 12Z/6AM Monday)...A shortwave will be traversing
the Intermountain West on Monday. Given modest mid level moisture
expect diurnal convection to develop during the afternoon.
Convective parameters suggest mainly general thunderstorms with some
gusty erratic outflow winds possible. The greatest probability (~30%
chance) for convection will be across the terrain of eastern Utah
given a majority of guidance has the shortwave axis moving through
the western half of Utah early in the day.

Temperatures on Monday will be relatively "cool" compared to the
following days as high temperatures will be ~5 degrees above normal.
As this shortwave exits, high pressure starts to re-establish itself
over the region. This will result in mostly dry conditions and clear
skies dominating with temperatures increasing 10-15 degrees above
normal by midweek. This translates to mid to upper 90s for most
valley locations with mid 100s across far southern Utah.

These hot temperatures will be tapered by the end of next week as a
cutoff low off the coast of southern California moves onshore and
helps to lower heights across the area. However, temperatures will
remain ~5 degrees above normal. 31% of guidance has a slower
progression of this low likely delaying its impacts by a day or so.
Regardless, all members do have this low moving through some time
late in the week. Southerly flow will increase ahead of the low
which will increase afternoon surface winds. Moisture will gradually
increase as well as this low moves onshore with afternoon convection
increasing. Guidance has the center of this low moving across
northern Arizona so precipitation chances will be higher further
south.

&&

.AVIATION...KSLC...VFR conditions will persist for the KSLC terminal
as conditions remain mostly dry with a few high clouds. A stray
thunderstorm is possible during the afternoon, but most convective
activity will remain well to the west of the terminal. A light
southerly wind will transition to a light northerly wind during the
afternoon.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist
for the airspace throughout the period. Afternoon convection is
expected across central Utah with mainly dry conditions for southern
and northern Utah. Winds will be light and variable.

&&

.FIRE WEATHER...Moisture will linger across the area today while
high pressure builds back into Utah. Expect generally isolated to
scattered showers and thunderstorms today. Showers will in general
be weaker than yesterday with a lower potential for wetting rain.
Gusty outflow winds will continue to be a threat with some of the
showers and thunderstorms. Tomorrow, another weak weather
disturbance will graze northern Utah. This will bring the threat of
somewhat stronger showers and thunderstorms with slightly higher
potential for wetting rain. Additionally, southwest winds will
increase across southern Utah, bringing marginal Red Flag
conditions. High pressure will then return to the area through
midweek, accompanied by a drying trend. Temperatures for the most
part will remain hot for this time of year. The next potential storm
looks to arrive late Thursday through Friday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Excessive Heat Warning until midnight MDT Saturday night for
     UTZ123-124-131.

WY...None.
&&

$$

Cheng/Mahan

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