St. George, Utah 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

222
FXUS65 KSLC 151053
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
453 AM MDT Wed Oct 15 2025

.SYNOPSIS...Unsettled weather is expected through Thursday as a cool
and moist Pacific system moves through. Drier conditions return by
Friday along with gradually warming temperatures. Models then
continue to show potential for another system early next week, but
uncertainty remains high at this point.

&&

.DISCUSSION...
Key Points:
- A moist Pacific system will result in unsettled weather through
Thursday. Rain and high elevation snow chances can be expected
across much of Utah today. Showers will then linger across northern
Utah and southwest Wyoming tonight through Thursday.

- The Pacific system will be accompanied by colder air which will
also settle in through midweek. This will result in potential for
locally freezing temperatures in some locations Thursday and/or
Friday morning, with some uncertainty noted due to cloud cover.

- Roughly 80% of ensemble members show potential for another cool
Pacific system to impact the region by early next week, though
uncertainty is noted in specific details at this time.


An upper low centered over the Sierra Nevada this morning will
continue to move towards Utah today. Ahead of this low, Utah remains
under a fairly moist southwesterly flow. Latest analysis shows PWATs
in the 0.4-0.6 inch range across Utah, representing 125-200% of
normal for this time of year.

Widespread but generally light to locally moderate rain has
continued across western and northern Utah overnight aided by upper
diffluence ahead of the low and with the jet core punching into the
area. As the low continues to move into Utah and pushes a cold front
into the area later this morning into this afternoon, expect
precipitation to fill in a bit more across the same areas before
lifting northeast through the state this afternoon. Tonight into
Thursday, as the low starts lifting out to the northeast, northern
Utah and southwest Wyoming will continue to see showers as moisture
wraps around the low.

Locally moderate rain rates could lead to isolated flash flooding,
especially if the heavier showers end up training over some of the
more sensitive areas. The NBM 25th percentile QPF from 6AM this
morning through 6AM Friday has around 0.25-0.3 inches across
northern Utah and around 0.05 inches across southwest Utah. At the
75th percentile, this increases to between 0.6-1.2 inches across
northern Utah and between 0.2-0.35 inches across southwest Utah.
More simply, there is a 40-60% chance of another 0.5 inches of
precipitation across northern Utah and 10-25% chance across
southwest Utah before the storm winds down tomorrow night. The
deterministic NBM seems to be hitting northern Utah on the lower end
and southwest Utah on the higher end, however. With lowering snow
levels, higher ridgelines (generally above 6500-7000 ft) could see
accumulating snow. The upper Cottonwoods and high Uintas have a 50-
75% chance of greater than 4 inches of snow, with a 20-45% chance
elsewhere along the higher peaks.

Cooler temperatures will settle into the area behind to cold front.
Temperatures will already be trending lower today, with afternoon
maxes 8-15 degrees below climo. Temperatures will continue to cool a
few degrees more in some locations tomorrow. Overnight mins will
have to potential to reach freezing both tonight and tomorrow night,
especially across central and eastern valleys where the growing
season my be ongoing. Chances are better tomorrow night as skies
will have less cloud cover. However, local areas in Castle Country
and the western Uinta Basin will be the most likely areas to see a
freeze tonight, impacting any unprotected, late-season agriculture.

High pressure will build into the area Friday through the weekend,
leading to drier conditions along with a warming trend. The next
storm system looks to impact the area by Monday, but much
uncertainty continues with regards to its timing and strength. The
00z global deterministics seem to be backing off as far as
precipitation amounts with this next storm.

&&

.AVIATION...KSLC...The chance for showers and isolated thunderstorms
will increase through the morning with the best chance of showers
and thunderstorms at the terminal coming during the 18-22Z
timeframe. Periods of MVFR CIGS/VIS can be expected with stronger
storms which pass over the terminal this afternoon. Winds will
generally remain southerly, however will become erratic and variable
at times through the day due to outflow from passing showers.

.REST OF UTAH AND SOUTHWEST WYOMING...Showers and occasional
thunderstorms can be expected through this evening across much of
northern Utah and southwest Wyoming, with periods of MVFR and
perhaps brief IFR CIGS/VIS within heavier showers. Across southern
Utah showers and isolated thunderstorms will persist through the
morning, with conditions improving and becoming predominantly VFR by
early afternoon. Winds across the region will remain generally
southerly, but will become variable near passing showers and
thunderstorms.

&&

.FIRE WEATHER...A storm system will continue to cross Utah today
into tomorrow. Fairly widespread showers and thunderstorms along
with a good chance (>50%) of wetting rain are expected, especially
across western, central, and northern Utah today. Precipitation will
then become confined more to northern Utah tonight through tomorrow.
With cooler air arriving behind a cold front today, snow levels will
lower to between 6500-7000 feet by tonight, allowing for
accumulating snow (generally 3-6 inches with locally higher amounts)
on the higher ridgelines. High pressure building into the area will
then bring drier and more stable conditions to the area for the end
of the week and into the weekend. The next storm system is still on
track for early next week, but significant model spread is noted.

&&

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

$$

Cheng/Seaman

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