735
FXUS65 KSLC 181015
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
415 AM MDT Sat Oct 18 2025

.SYNOPSIS...A drying and warming trend is expected through Sunday
before a cold front passes through northern/ western Utah and
southwest Wyoming Sunday night through Monday morning. Another
area of low pressure moves through central/ southern Utah mid-week
with high pressure building thereafter.

&&

.SHORT TERM (Through 12Z/6AM Tuesday)...A relatively cool post-
frontal northwesterly flow will remain in place across the
northern half of the CWA through today while the southern half of
the area gradually warms as we begin the transition to a south to
southwesterly flow. Dry conditions are expected across the area
through the daylight hours with high temperatures expected to be
near to slightly below normal.

Through Sunday, flow will increase out of the southwest ahead of
the next trough that is set to graze the forecast area Sunday
night through Monday morning. A notable period of relatively
strong warm air advection will spread over Utah and southwest
Wyoming, allowing high temperatures to climb back to above-normal
levels across much of the area. In addition to the late season
warmth, breezy southwesterly winds are expected during the
afternoon hours with the strongest winds anticipated west of the
I-15 corridor. At this time, there is a near zero percent chance
that these winds will become strong enough to warrant headlines.
However, afternoon wind gusts will peak between 20-30 mph across
the aforementioned area.

Sunday night, the grazing trough will begin passing through the
northern area, draping a cold frontal boundary into Utah and
southwest Wyoming. Current model guidance is supportive of this
cold front progressing through northern Utah and southwest Wyoming
Sunday night through early Monday morning, brining isolated to
widely scattered snow showers across the far northern mountains
and light rainfall to the far northern valleys (i.e. Cache, Bear
River, and Ogden Valley). Little to no impact is expected with
these showers, however, there is about a 10% chance that we will
see upwards of 1 inch of snow near the high point of US-89 through
Logan Canyon.

The cold front will continue its track through the western Utah
valleys through the early morning hours on Monday, likely not
carrying enough momentum to reach lower Washington County and/ or
the lower elevation valleys of eastern Utah. For the areas that do
see the frontal boundary (western/ northern valley areas), expect
temperatures to fall back below normal for Monday alongside dry
conditions. The biggest impact to note in the wake of this cold
front will be the potentially freezing temperatures on Tuesday
morning for areas in the far northern Utah valleys, as well as the
Uinta Basin.

.LONG TERM (After 12Z/6AM Tuesday)...The long-term period will be
relatively quiet, with low precipitation chances and temperatures
sitting around normal for this time of year. The coolest
temperatures of the long-term are expected on Tuesday morning,
though active agriculture areas will likely remain above freezing.

After a brief period of high pressure on Tuesday, a closed low
moving in from the southwest will pass across southern Utah/northern
Arizona on Wednesday afternoon and evening, bringing isolated to
scattered showers to mostly southern/eastern Utah. While there is
still some decent spread in QPF, most locations will see less than
0.10-0.25" given an overall lack of moisture...though the NBM 90th
percentile suggests up to 0.50" in the southern mountains is
possible. Snow levels, while dipping slightly with the passage of
the wave, will still likely remain above 9500ft.

High pressure will then rebuild across the region, with near-normal
high temperatures in the upper-60s along the Wasatch Front and most
other lower elevation valleys. In other words, a beautiful few days!
However, this dry spell will not last long, as model guidance is
pretty honed in on a broad longwave trough entering the western US
next weekend.


&&

.AVIATION...KSLC...Diurnally-driven winds will continue, with
southeasterly flow transitioning to northwesterly around 17-18z. VFR
conditions will prevail with mostly clear skies.

.REST OF UTAH AND SOUTHWEST WYOMING...Winds will remain largely
light and terrain-driven with VFR conditions and mostly clear skies
prevailing. The one exception is any fog development around 12-15z,
particularly near KLGU and KHCR, though this chance is low (<20%).

&&

.FIRE WEATHER...A dry and stable northwesterly flow will begin to
shift toward a more west to southwesterly flow over the next
24-36 hours, promoting deeper mixing and a more unstable low-level
environment. Through Saturday, temperatures will warm ever so
slightly as the previous cold airmass continues to depart the
region, with warmer west to southwest flow spreading into the
region late in the day. Daytime highs are expected to run right
around normal for this time of year alongside increasingly dry
relatively humidity values. Afternoon minimum RH will drop by 5 to
15 percent as compared to Friday, with the most aggressive drying
trend being noted across far northern Utah. For the lower lying
valley areas of southern Utah, values are anticipated to drop back
into the 20 to 25 percent range.

A stout warming and drying trend is expected to continue into
Sunday as dry south to southwest flow spreads across much of Utah
ahead of the next low pressure system. Afternoon humidity will
trend downward by another 5-10 percent alongside increasingly
gusty afternoon winds. Of note, west-central to southwest Utah are
the two main areas of concern for elevated to near-critical fire
weather conditions as humidity will fall into the 15 to 20 percent
range alongside peak gusts between 20 to 30 mph. The strongest
winds, however, will be confined to the far northern Utah
mountains where gusts will likely exceed 35 mph in some of the
higher exposure terrain. That said, humidity in this area will
only bottom out around 30 to 40 percent.

The aforementioned cold front will progress through the northern
area Sunday night into Monday morning, bringing a shift in wind
direction to the north to northwest. The front itself is currently
anticipated to progress through the western valleys of Utah
through early Monday, bringing a similar wind shift and cooling
trend. Only the northern mountains (Salt Lake County northward)
will see a shot of light precipitation with low end probabilities
of wetting rains (10 to 30 percent). Stable conditions build in
the wake of this cold front through at least the middle of next
week. Around Wednesday, another low pressure system will move in
from the south, helping to bring a round of light precipitation to
the central and southern mountains, as well as maintaining cooler
temperatures across the state.

&&

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

$$

SHORT TERM...Webber
LONG TERM...Cunningham
AVIATION...Cunningham
FIRE WEATHER...Webber

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http://weather.gov/saltlakecity