000
FXUS65 KSLC 112214
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
414 PM MDT Tue Jun 11 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/6PM Thursday)...
The main impact in the short term will be the hot temperatures.
With the focus starting in southern Utah for the Glen Canyon
NRA/Lake Powell area where an Excessive Heat Warning is in place
for Wednesday and Thursday. The heat then expands northward into
northern Utah, starting Wednesday, but really peaking on Thursday.
Heat Advisories have been added for the Wasatch Front and West
Desert zones in for Wednesday and Thursday.

High pressure will continue to build over the Four Corners area
into Wednesday, with the ridge axis amplifying northward into
Northern Utah. By Thursday, the ridge will start to be pinched
downstream as filling closed low moves inland off from the
southern California Coast. This will increase the southwesterly
flow across the forecast area as the flow accelerates between the
low to our west and high to our east, as well as pull the thermal
ridge axis farther north, into northern Utah. H7 temperatures will
reach +16 to +18C Wednesday and Thursday. Also on Thursday, mid-
level moisture will start to increase from south to north, mainly
focused across the central spine of mountains eastward. This will
start to limit the heat slightly for southern and eastern portions
of UT, but northern UT will remain under hot/dry and breeze
conditions. All this to say that Wednesday and Thursday will both
be hot across the region, but the heat will maximized across
southern Utah on Wednesday, followed by northern Utah on Thursday.
In addition, the cloud cover will increase into northern Utah
Thursday night, along with elevated winds ahead of the low
pressure system. This will keep northern Utah valleys well mixed
and insulated with the cloud cover overnight, all working together
to keep temperatures elevated overnight. Thus the HeatRisk for
northern Utah is more elevated into Thursday given the hot daytime
temperatures around 100 followed by a very warm night Thursday
night. Temperatures at KSLC will likely struggle to cool out of
the 80s and into the mid-70s by early Friday morning. These warm
overnight lows act to increase the HeatRisk through limiting
nighttime relief from warm temperatures for vulnerable
populations.

Otherwise, the chance for showers moving into south-central and
eastern Utah increases Thursday night ahead of the low pressure
system as is continues weakening and moving toward the Four
Corners.

.LONG TERM (After 00Z Friday/6PM Thursday), Issued 339 AM MDT...
Friday marks the transition to more unsettled weather across
northern UT and southwest WY, at least to start the long-term
period. A closed low over SoCal will weaken as it moves inland,
tracking across southeastern UT on Friday and bringing a decent
mid-level moisture surge with it...PWATs across southeastern UT
jump from an ensemble mean of 0.35" up to 0.75". Thus, scattered
showers will develop in eastern UT beginning late Thursday night,
with thunderstorms and high-based convection developing Friday
afternoon. Temperatures will also decrease across the area on
Friday, with eastern UT seeing the largest decrease by about 10-15
degrees as compared to Thursday afternoon highs.

Moving into the weekend, our sensible weather starts to be
peripherally influenced by a low pressure system settling over the
PacNW, though the air mass remains quite dry. Currently, the biggest
impact looks to be a cooling trend beginning Saturday, mainly across
northern areas. Model guidance really starts to diverge in the upper-
level pattern on Sunday, which will ultimately determine the extent
of this cooling trend across the area. Ensemble members are split
roughly 70-30, with 70% of members favoring a stronger cooldown on
Sunday into Monday, associated with a more amplified trough. The
other 30% favor not much of a cooldown at all. To further illustrate
the high uncertainty, highs at KSLC on Monday range from 70F to 85F
(25th to 75th percentiles). In St. George, this range isn`t quite as
big, but still ranges from 92F to 100F.

&&

.AVIATION...KSLC...Light northwest winds will transition to
southeast around 03Z with clear conditions. Clear conditions will
continue through around 18Z when winds transition to northwest. A
few clouds will build around nearby terrain through the day, but
conditions will stay mostly clear.

.REST OF UTAH AND SOUTHWEST WYOMING...Clear conditions with light
winds will last through the night. Clear conditions will last
through the morning, with clouds likely building around nearby
terrain in northern Utah during the afternoon. Southwest winds will
gust around 25 knots throughout southwest Wyoming and southern Utah
from 18-03Z.

&&

.FIRE WEATHER...
High pressure will maintain hot and dry conditions across the
area Wednesday and Thursday with temperatures running above
average, and very low humidity values into the teens and single
digits. Locally critical fire weather conditions will develop
across portions of western and eastern Utah on Thursday. There is
about a 40-60% chance of seeing RH values <10% combined with wind
gusts of 35 mph or greater across western Utah, mainly in zones
495 and 492. There is similarly a 20-50% chance of those same
weather conditions across eastern UT zones of 498, 494, and 489.

Moisture will increase across eastern Utah on Friday brining a
low chance for wetting precipitation, as well as increasing
humidity. This will also increase the thunder/lightning potential,
as well as the potential for gusty/erratic outflow winds. Very
dry conditions however will persist across western Utah which will
remain west of the main moisture axis. Looking into next week
there is an increasing potential for cooler temperatures,
especially across northern Utah, either near or slightly below
normal.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Heat Advisory from 11 AM Wednesday to 6 AM MDT Friday for UTZ101-
     104>106.

     Excessive Heat Warning from 11 AM Wednesday to 10 PM MDT
     Thursday for UTZ131.

WY...None.
&&

$$

SHORT TERM...Church
LONG TERM...Cunningham
AVIATION...Wilson
FIRE WEATHER...Church

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