618
FXUS65 KSLC 301016
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
416 AM MDT Tue Apr 30 2024

.SYNOPSIS...A stalled front will remain draped across central Utah
today, separating a cooler and more stable airmass across northern
Utah from a warmer airmass across the south. A secondary cold
front will cross the region tonight, bringing additional cooling
for Wednesday.


&&

.SHORT TERM (Through 12Z/6AM Thursday)...A shortwave trough
exiting the region as it crosses the central Rockies is leaving a
predominantly zonal flow in its wake across the Great
Basin/Colorado Plateau region. The associated surface front
currently bisects the forecast area as it stalls roughly along a
Cedar City to Green River line. This boundary will slowly mix
northward into central Utah today, separating a cooler and more
stable airmass across northern Utah from a more mild and well
mixed airmass to the south. Max temperatures across the northern
valleys will trend roughly 10F cooler, ranging from the mid 50s in
the Cache Valley to low 60s along the central and southern
Wasatch Front. To the south of the boundary, temperatures across
southern Utah will trend a degree or two warmer, reaching the low
70s around Cedar City, and low to mid 80s around St George, Zion
Canyon and Bullfrog.

The next shortwave trough will brush the northern Great Basin late
tonight through Wednesday, pushing a re-enforcing surge of cold
air into the region. Precip chances with this wave and along the
associated frontal boundary are minimal...generally 20-30% along
the higher terrain. The secondary surge of cold air will knock
another 5F or so off high temperatures areawide Wednesday, with
highs only reaching the low to mid 50s across the northern
valleys. Depending on cloud cover Wednesday night, some outlying
areas along the Wasatch Front such as near Tremonton/Brigham City
as well as southern Utah Valley may dip to near freezing.

.LONG TERM (After 12Z/6AM Thursday)...Southwest Wyoming and northern
Utah will get more shortwave energy through later in the week.
Isolated to scattered showers, primarily mountain snow showers are
likely. Ensembles are in general agreement on a longwave trough
pushing in during the weekend or near the start of the week.

Thursday morning will likely be the coldest of the week, as a
shortwave trough will be exiting with clearing conditions. Low
temperatures will generally be above freezing for valleys of the
urban corridor, but below freezing temperatures are likely for the
Cache Valley, portions of eastern Box Elder County, and around Cedar
City.

Another shortwave trough will track into southwest Wyoming and
northern Utah into Friday. Isolated to scattered valley rain and
mountain snow showers are forecasted, with any rainfall or snowfall
totals light. As the main trough lifts into Canada, the baroclinic
zone will likely not track into southern Utah. Roughly 75% of
ensemble members have the baroclinic zone reaching as far south as
roughly Beaver, Piute, and Wayne counties. From the southern extent
of the cold front, northward to the Idaho border, temperatures will
be 5-10F warmer than normal. South of the cold front, temperatures
will be 5-10F warmer than normal.

There is good confidence that shortwave ridging will build into Utah
Friday into Saturday, with a warm and dry Saturday.

A longwave trough will be digging to the west Saturday. Uncertainty
gets higher with details for the end of the weekend. Roughly 65% of
ensemble members have the trough digging into Utah, where valley
rain and mountain snow would be likely, while roughly 35% of members
have it far enough to the west for dry conditions and gusty winds.
Once the storm system pushes into Utah, measurable valley rainfall
is likely with accumulating mountain snowfall.

&&

.AVIATION...KSLC...Light northwest winds will prevail through the
day. Clear skies will transition to scattered afternoon cloud cover.
Clouds will increase into the evening as a rather dry cold front
pushes in from the northwest. Winds will likely transition to
southeast around 03Z, but switch to northwest once the front tracks
through around 06-08Z.

.REST OF UTAH AND SOUTHWEST WYOMING...Clear skies with relatively
light winds will last through the morning. Clouds will increase for
southwest Wyoming and northern Utah during the afternoon and evening
with gusty southwest winds in southwest Wyoming. Clear skies will
last through the day in southern Utah with gusty southwest winds
most of the afternoon. A relatively dry cold front will track into
northern Utah around 03Z, transitioning winds to northwest as it
tracks south.&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

Seaman/Wilson

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