324
FXUS65 KSLC 032202
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
402 PM MDT Mon Jun 3 2024

.SYNOPSIS...A passing cold front will bring showers and
thunderstorms to southwest Wyoming and northern Utah today. High
pressure will build over the region beginning Tuesday, bringing
dry and increasingly hot conditions through the end of the work
week.

&&

.SHORT TERM (Through 12Z/6AM Wednesday)...Early Monday afternoon,
a diffuse cold front was moving southward across northern Utah.
Model consensus strongly suggests the cold front will wash out
across central Utah tonight. Enhanced mid-level atmospheric
moisture courtesy of a decaying atmospheric river will combine
with an embedded shortwave to produce an area of showers (with an
isolated thunderstorm or two) across northern Utah this evening,
centered over northeast Utah. On the southern fringes of this
activity over east-central Utah early this evening, largely virga
(precipitation that evaporates before it reaches the ground) is
expected. The highest DCAPE values near 1000J/kg will be found
here, and this is where HREF probabilities for gusty winds are
highest, with gusts in the 45-55 mph range most likely. A trailing
wave will support a few additional showers near the Idaho and
Wyoming borders overnight.

A drying trend will commence on Tuesday behind today`s cold front,
with temperatures at comfortable near normal levels across
northern and central Utah, but a much warmer 5-10F above normal
across southern Utah. The ridge then begins to build across the
area in earnest by Wednesday, and this will mark the commencement
of the first heatwave of the season.


.LONG TERM (After 12Z Wednesday), Issued 300 AM MDT...
Wednesday will be the first day in what will be several
consecutive days of much warmer than normal temperatures. This
will be as a powerful ridge slides inland from the eastern Pacific
and builds into the western U.S. Southwest Wyoming and northern
Utah will have the biggest increase in temperatures from Tuesday,
with valley highs in the mid to upper 80s. Temperatures will get
into the 90s for most southern Utah valleys, while lower
Washington County will get into the 100s.

Temperatures will warm further Thursday. There is good model
agreement on the ridge axis positioned over Utah, extending far to
the north. Valley high temperatures throughout northern Utah will
range from the low 90s near the Idaho border to the mid 90s for the
urban corridor. Mid to upper 90s are likely for many central
valleys, and 100s are likely around Lake Powell and again for lower
Washington County. An Excessive Heat Watch is in effect starting
Thursday for both Lake Powell and lower Washington County. Along
with the day temperatures, minimal cooling will happen overnight for
those locations, with low temperatures in the low to mid 70s.

The ridge axis will be nearly over Utah or slightly downstream
Friday. Models are in general agreement on weak shortwave energy
tracking into Utah within anticyclonic flow as the axis tracks east.
Shortwave energy along with warming of the day will bring more
clouds. Isolated showers and thunderstorms will almost exclusively
stay around terrain with weak forcing, little moisture, and minimal
wind shear. For temperatures, nearly identical numbers to Thursday
are likely. Forecast highs and lows each day are almost all less 5F
from record highs and lows throughout southwest Wyoming and Utah.
The Excessive Heat Watch for those aforementioned locations is in
effect through Friday.

There is a bit more uncertainty into the weekend on details with the
ridge. Most likely, it will stay in place, but not be as strong as
late in the week. There is general agreement on shortwave energy
rotating into Utah with isolated to scattered showers and
thunderstorms, primarily near higher terrain.

&&

.AVIATION...Rain showers this evening are expected with
overcast skies. Occasional gusts out of the west to northwest are
forecast into the early evening before winds decrease the remainder
of the evening and overnight hours. For tomorrow morning, light
northwest winds and VFR conditions are forecast.

.REST OF UTAH AND SOUTHWEST WYOMING...Overcast skies are noted
across much of northern and central Utah as well as southwest
Wyoming. VFR conditions are still expected as these clouds are in
the mid to upper levels. Occasional rain showers can also be
expected. In southern Utah, breezy conditions this afternoon will
decrease by the evening with light winds mostly clear skies.

&&

.FIRE WEATHER...A Pacific Northwest storm system will bring a cold
front across northern Utah during the day today, with good
coverage of showers along with a few thunderstorms, primarily
during the afternoon and early evening. The best chance of wetting
rainfall will be for areas north of I-80, with the highest
chances over northeast Utah. As the system exits the area, a ridge
will build over the area through the rest of the work week,
resulting in dry and increasingly hot conditions. Uncertainty
increases as the weekend approaches, with a chance of a dry
lightning threat due to increasing mid-level moisture, especially
over northern Utah. Overnight recovery will remain poor through
the week across southern Utah, and become increasingly poor across
northern Utah through the week. Temperatures will challenge
records for the time of year for Thursday and Friday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Excessive Heat Warning from 11 AM Thursday to midnight MDT
     Friday night for UTZ123-131.

WY...None.
&&

$$

ADeSmet/NDeSmet/Wilson

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