685
FXUS65 KSLC 102126
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
326 PM MDT Mon Jun 10 2024

.SYNOPSIS...Very hot temperatures will build into the region
Wednesday into Thursday, with the potential for the Wasatch Front
to breach the century mark. An upper level low may bring cooler
temperatures and precipitation by Friday.

&&

.SHORT TERM (Through 00Z Friday)...A weak cold front brought a bit
of relief from the very hot temperatures for a good portion of the
Beehive State today...though this relief is short-lived as high
pressure once again builds across the region. Afternoon upper air
and satellite analysis indicate a shortwave trough embedded in the
northern stream quickly moving into the High Plains. A cut-off low
is located off the southern California coast with a broad upper
level ridge across the eastern Pacific.

Relatively weak convection is firing on an instability gradient
across northern Utah into Uinta County WY, with the typical
convection near the Boulder Mountain area. As per usual with a
relatively dry sub-cloud environment, isolated microbursts are
possible.

As high pressure builds into the area, temperatures will again
reach toward well above normal levels by Wednesday. For example,
looking at the Salt Lake City temperatures, the deterministic
National Blend of Models suggests 100F will be breached Wednesday
and Thursday. While this isn`t the earliest (the earliest was June
4, 2021), it would be within the top 10 earliest 100F on record.
Either way, anomalously hot temperatures can be expected Wednesday
and Thursday. An Excessive Heat Watch remains in effect for Glen
Canyon National Recreation Area, though the latest guidance
suggests cloud cover may reduce temperatures a few degrees. For
this reason, held off on upgrading to a warning.

For the Wasatch Front, Heat Advisories may be needed Wednesday and
Thursday if future forecast runs continue to show 100F+ across the
area. Regardless, it will be very hot state-wide Wednesday and
Thursday.

.LONG TERM (After 00Z Friday), Issued 416 AM MDT...The heat will
not last long as a closed low situated off the coast of SoCal
begins to shift inland, reaching southern/eastern UT by Friday.
Highs on Friday will thus decrease by around 5-15 degrees across
the area with the greatest decrease across eastern areas along the
track of the low. Scattered high-based convection is also looking
more likely along and east of the central spine of Utah mountains
during the afternoon.

Heading into the weekend, uncertainty in the longwave pattern
increases. Ensemble guidance favors some sort of trough moving into
the PacNW early in the weekend, though there is plenty of
disagreement in how it evolves across the Intermountain West.
Roughly 59% of ensemble members favor a deeper trough resulting in a
greater cooldown over Utah, while the other 41% of members suggest
the trough remains fairly zonal and far to our north. To quantify
this uncertainty further, the 25th-75th percentiles for 700-mb
temperatures range from +4C to +13C...dropping from +17C on Thursday.

&&

.AVIATION...KSLC...Light northwest winds will transition to
southeast around 06Z with clear conditions. Clear or mostly clear
conditions will continue, with a transition to northwest winds
around 18Z.

.REST OF UTAH AND SOUTHWEST WYOMING...Isolated showers for
portions of northern and southern Utah will diminish by 03Z.
Showers will be capable of gusty, erratic outflow winds. Clear or
mostly clear conditions are likely overnight with light winds.
Similar conditions will continue through the day.

&&

.FIRE WEATHER...A brief break in the very hot temperatures continues
across the area this afternoon. Temperatures will climb once
again as high pressure builds into the area, with well above
normal temperatures expected by Wednesday. With a dry airmass in
place, winds will increase across southwestern Utah ahead of a
weak upper level system slowly crossing into southern California.
This will bring locally critical fire weather conditions Wednesday
and Thursday to southwestern Utah.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Excessive Heat Watch from Wednesday morning through Thursday
     evening for UTZ131.

WY...None.
&&

$$

Kruse/Cunningham/Wilson

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