809
FXUS65 KSLC 120838
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
238 AM MDT Sun May 12 2024

.SYNOPSIS...As a low exits into Colorado, high pressure will build
over the Great Basin today, bringing a continued warming trend and
drier conditions than the past few days. A weak storm system will
graze northern Utah late Monday afternoon into the evening before
another system moves through the area Tuesday into Wednesday,
bringing less warm and more unsettled conditions. High pressure
will return late in the week.

&&

.SHORT TERM (Through 12Z/6AM Tuesday)...Radar has finally cleared
out early this morning as a slow moving low pressure system has
finally made its way into western Colorado. Behind the exiting
trough, low pressure is building over the Great Basin with the
ridge axis on track to move into Utah by this evening. With the
ridge building, Utah and southwest Wyoming will see a drier and
noticeably warmer day today with maxes averaging 5F above seasonal
normals. Despite the ridge moving in, enough instability will
linger over the eastern half of the area to result in primarily
isolated convection east of I-15 this afternoon and into the early
evening. Gusty winds would be the main threat with any storms that
develop.

By Monday morning, the ridge is expected to flatten as a weak
Pacific Northwest system moves over the top of it. This wave is
expected to graze northern Utah late Monday afternoon into the
evening, bringing a bit of cooling along with an increase in
shower activity, primarily for areas near the Utah/Idaho border.
However, given the relatively late time of arrival of the system
much of the day will be quite warm, with temperatures topping out
around 10F above normal for this time of year.

.LONG TERM (After 12Z/6AM Tuesday)...A Tuesday cold front
remains in our forecast with a trough of low pressure forecast to
impact the region. The front is not bringing too much upper level
support with it, so this will be one of those `you`ll notice the
wind shift and cooler temperatures behind it if you`re watching for
it` otherwise you won`t notice.

Ensembles are not especially impressed with this trough/front. It is
at least showing up now as a weather feature when it wasn`t
yesterday, so confidence that a trough/front with some degree of
strength will pass through the region Tuesday has increased. Now,
how much that`ll really impact the region still, unfortunately,
isn`t clear. The boundary still looks likely to stall somewhere in
the state through Wednesday.

Let`s break down some scenarios though for Tuesday`s forecast.
The most likely scenario we are looking at involves a split across
west and eastern Utah. A mostly dry forecast would be anticipated
across western Utah, whereas showers and thunderstorms become
more likely in eastern Utah (40% likelihood or greater). Another
scenario (about a 15% chance of happening and most favored by the
Canadian model) involves a very wet forecast south of I-70 and a
dry forecast north of there. These would be showers and
thunderstorms during the afternoon and early evening hours only
when daytime heating allows for building, which happens to
coincide with the forecast frontal passage by the Canadian model.

Thursday into Friday`s forecast thankfully has some semblance of
a consensus now; indicating a building ridge from the west and
thus warming temperatures and dry conditions. Headed into the
weekend continues the hodge podgeyness of model solutions from
yesterday where confidence in the forecast lowers as a result.

&&

.AVIATION...KSLC...VFR conditions are forecast throughout the day.
Light southeast winds are forecast to shift northwest early this
afternoon with flow returning from the southeast in the early
evening.

.REST OF UTAH AND SOUTHWEST WYOMING...High based clouds and light
winds are forecast today allowing for VFR conditions across the
region.

&&

.FIRE WEATHER...The low pressure system that had been impacting the
area over the past few days has moved into Colorado, allowing high
pressure to build over Utah. This will result in noticeably warmer
temperatures today will less in the way of shower and thunderstorm
coverage than seen the last couple of days, but isolated storms
are still anticipated over the higher terrain of northern Utah
this afternoon. The ridge will flatten Monday as a weak storm
system grazes northern Utah, bringing a greater chance of storms
to areas near the Utah/Idaho border. Another system will impact
the area Tuesday into Wednesday, bringing less warm temperatures
and increasing coverage of showers and thunderstorms. High
pressure is expected to move back in late in the week and into the
weekend, bringing drier and warmer conditions.

&&

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

$$

SHORT TERM/FIRE WEATHER...Traphagan
LONG TERM/AVIATION...NDeSmet

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