Spanish Fork, Utah 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

093
FXUS65 KSLC 122300
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
400 PM MST Tue Nov 12 2024

.SYNOPSIS...High pressure will bring dry conditions with lighter
winds throughout Utah Wednesday. A storm system Friday into the
weekend will bring valley and mountain snow accumulation. Another
storm system could track into Utah early next week.

&&

.SHORT TERM (Through 12Z/5AM Thursday)...The trough axis from
Tuesday`s rain and snow event has tracked to the east, with a
drier post-frontal northwest flow into southwest Wyoming and
Utah. Most precipitation has tapered off, with snow showers
primarily for the northern mountains. Precipitation will be more
showery through the evening and eventually taper off.

Strong, gusty northwest winds in excess of 50 mph have been
recorded in the west desert and throughout higher terrain. Winds
will remain enhanced through the evening, with the strongest
valley winds in downslope portions of Castle Country. For locations
from roughly Price to Fremont Junction, wind gusts in excess of
50 mph are likely through around 9 p.m.

Shortwave ridging will track across southwest Wyoming and Utah
early Wednesday, with dry conditions through the day. Southwest
winds will enhance by later Wednesday into Thursday, especially
at higher elevations as a storm system digs off the Pacific coast.

.LONG TERM (After 12Z/5AM Thursday)...

Key Messages for the Extended Forecast:

* A storm system Friday night into Saturday will bring
  accumulating mountain snow (40-75% chance of exceeding 9 inches
  in the northern and central Wasatch), while valleys will
  transition from rain to snow with limited snow accumulation
  potential (<15% chance of exceeding 1 inch).
* A colder/wetter storm system is possible (80% chance, with about
  35% chance of a much colder/wetter system) Monday into Monday
  night with more mountain snow accumulations. Valley locations may
  see a faster transition to snow with accumulating snow possible
  (40% chance of 1 inch or greater). There is a low chance (10-20%)
  of a more significant valley snow accumulation exceeding 6 inches.

Thursday into early Friday the area will be under deep southwesterly
flow ahead of a large trough cutting off over the Great Basin. This
will bring continued mild temperatures, near to 5 degrees above
normal. Clusters are in fairly good agreement in a splitting trough
with a northern wave ejecting across northern Utah Friday afternoon,
while the bulk of the trough digs well to our southwest and cuts
off over southern California and northern Mexico. This will give a
quick shot of precipitation late Friday through early Saturday,
mainly across northern Utah with the ejecting northern shortwave.
With the bulk of the wave cutting off well to our southwest,
dynamics and cold air over the forecast area will be fairly
minimal. Thus impacts from this storm system are largely going to
be limited to accumulating mountain snow. There is a 40-75%
chance of exceeding 9" of snow (winter weather advisory amounts)
in the northern and central Wasatch, with less than a 20% chance
of exceeding 18 inches (warning amounts). For valley`s there is
about a 15% chance of seeing snow accumulations of 1 inch or
greater. This is largely due to the limited cold air with this
storm system, such that even as precipitation transitions to snow
in the valleys, temperatures will be very marginal and will limit
snow accumulation potential, especially into the day on Saturday.

The next period of interest comes Monday into Tuesday as a
reinforcing trough moves in from the Pacific Northwest. There is a
larger range of potential outcomes with this next storm system.
Around 35% of ensemble solutions have a deeper trough maximizing
over the Great Basin with an ample cold air and moisture source.
Around 48% of solutions have a more progressive trough passage with
still relatively colder temperatures. The remaining 17% of solutions
have a very flat shortwave trough moving through the Pacific
northwest with minimal cold air or moisture moving into Utah. These
scenarios mean there is quite a range of potential, especially when
it comes to snow accumulations for the northern Utah valleys. For
SLC specifically, there is only about a 40% chance of seeing snow
accumulations of 1 inch or more Monday into Tuesday, which matches
up with colder/wetter scenarios mentioned above. However, there is
also about a 20% chance of seeing 6 inches of snow at SLC. Which
means IF the colder/wetter scenario materializes, then there is
almost a 50% chance that it could be a more significant event for
the valley. For the mountains, there is a little more confidence on
accumulating snow, with a 40-60% chance of exceeding 6 inches, and
even about a 25% chance of exceeding 18 inches locally in the
central Wasatch. However, we have to keep in mind there is still a
number of solutions (17%) that keep us mild and drier and we can`t
discount those solutions yet either. Thus we`ll have to keep a close
eye on how the model ensemble solution space evolves as we get
closer to this forecast period.

&&

.AVIATION...KSLC...Rain, occasionally mixed with snow, will diminish
this afternoon into early this evening, with MVFR CIGs/VIS improving
slowly to VFR into the evening hours, especially after 00Z. Quieter
weather will persist into Wednesday with a return to typical diurnal
wind shifts but otherwise VFR conditions prevailing.

REST OF UTAH AND SOUTHWEST WYOMING...Precipitation will continue
through the morning across much of the area, with most valleys
transitioning to snow early this morning as a cold front moves
through (the exception being the lowest elevations like KSGU).
Periods of moderate to heavy precipitation are possible, especially
later in the morning, with MVFR-IFR conditions and mountain
obscuration likely for many sites. Conditions will begin to improve
after 18z, with some lingering showers holding on through mid-
afternoon. Southwesterly winds ahead of the front will abruptly
transition to breezy out of the northwest to north. The strongest
gusts will be found downwind of higher terrain, such as at KENV,
KBCE, and KPUC.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory until 7 PM MST this evening for UTZ110-
     111.

     Winter Weather Advisory until 5 PM MST this afternoon for UTZ112-
     113.

     Wind Advisory until 9 PM MST this evening for UTZ120.

WY...None.

&&

$$

SHORT TERM...Wilson
LONG TERM...Church
AVIATION...Church

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