029
FXUS65 KSLC 011029
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
429 AM MDT Wed May 1 2024

.SYNOPSIS...A cool but relatively stable airmass will reside
across much of Utah and southwest Wyoming today, as a cold front
moves away from the region. A relatively cool and unsettled
pattern will persist through the remainder of the week, with the
next weather system affecting northern Utah and southwest Wyoming
Thursday night into Friday.

&&

.SHORT TERM (Through 00Z Saturday/6PM Friday)...A shortwave trough
evident in satellite imagery and objective analysis is digging
through the northern Rockies and northern Great Basin early this
morning. A stalled frontal boundary continues to bisect the area,
and extends roughly along a Cedar City to Green River line. As the
upper jet associated with the shortwave trough interacts with this
boundary, scattered showers have developed along the cool side of
the boundary and will likely continue into the morning hours.
Meanwhile a secondary surge of cold air associated with this
trough is currently spreading into northern Utah. This colder air
will continue to push south, effectively re-enforcing the stalled
frontal boundary this morning before the boundary pushes southeast
through the remainder of the area this afternoon. The focus for
showers will shift into areas from roughly Capitol Reef eastward
this afternoon, before exiting the forecast area this evening.

With this colder air overspreading the area, max temperatures
across northern/central valleys will trend 4-6 degrees cooler
today, running in the low to mid 50s along the Wasatch Front which
is roughly 10F below climo. Meanwhile max temps across southern
Utah behind the front will trend 4-8 degrees cooler than Tuesday.
With this cooler air mass in place, temperatures will fall near or
below freezing across many locations overnight. Although much of
the Wasatch Front will remain in the mid to upper 30s, outlying
agriculture areas outside of Brigham City as well as more rural
portions of Utah Valley will see temperatures approach freezing.
Some question remains regarding cloud cover overnight as the broad
flow pattern remains cyclonic, and therefore have held onto the
Freeze Watch for these locations. Other forecast zones such as
the Cache Valley and central/southwest Utah (excluding St George)
have not yet reached the date for freeze warnings, thus no
products are in effect for these areas.

A general cyclonic west to northwest flow will remain across the
region through the remainder of the week. The airmass will modify
a bit Thursday allowing temperatures to trend 5F warmer for most
valleys. A more organized wave within this flow will bring a
chance of showers to northern Utah Thursday night through Friday
morning with minimal QPF expected. Cooler air associated with this
wave will result in little change in temperatures from Thursday to
Friday across the north, with a slight warming trend forecast
across the south.


.LONG TERM (After 00Z Saturday/6PM Friday)...Clouds will diminish
through Friday evening as shortwave ridging tracks across Utah and
southwest Wyoming. Temperatures Saturday will start in the 30s and
40s for most valleys. The ridge axis will be east of the area
Saturday morning, while an upstream trough will be digging into the
PacNW. With the approaching trough and exiting shortwave ridge, flow
aloft will increase through the day. Flow at 700 mb Saturday morning
will be around 15 knots, but by Saturday evening, 50 knot or higher
winds are likely there. Strong warm air advection with dry
conditions will allow for a big range in temperatures. Morning lows
will be roughly 5-10F cooler than normal. Most valley high
temperatures will be into the 70s, roughly 5-10F warmer than normal.
Winds will be strongest throughout western Utah during the afternoon
and will stay enhanced into Sunday.

The longwave trough will dig southeast into Sunday. There are timing
differences, so uncertainty Sunday when a baroclinic zone will track
into Utah. Ensemble guidance ranges from early in the day to late on
a north to south oriented cold front. With the timing differences,
there is uncertainty if gusty southwest winds would last much of the
day or if precipitation would push in with lighter winds. Confidence
is better as the day goes for the boundary to track across Utah.
Valley rain and snow above roughly 8000 feet are likely initially.
As colder conditions build in into Monday, snow is likely to roughly
6000 feet. Once the trough axis tracks over Utah, moist, unstable
northwest flow will bring more snow to the northern mountains.

Rain and snow will taper off Monday into Tuesday, but ensembles are
in good agreement on a shortwave trough quickly tracking in Tuesday
with light valley rain and mountain snow.

&&

.AVIATION...KSLC...Northwest winds will last through the day with
gusts around 20 knots much of the afternoon. Mostly clear conditions
to scattered clouds are likely.

.REST OF UTAH AND SOUTHWEST WYOMING...A relatively dry cold front
will push into southern Utah, transitioning winds to northwest
during the morning. West to northwest winds will last through the
day throughout southwest Wyoming and Utah, with gusts around 20
knots. Largely dry conditions are likely with isolated mountain
showers.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Freeze Watch from late tonight through Thursday morning for
     UTZ103-106.

WY...None.
&&

$$

Seaman/Wilson

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