225
FXUS65 KSLC 161003
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
403 AM MDT Sun Jun 16 2024

.SYNOPSIS...Winds increase over the southern and eastern portions
of Utah today, bringing increasing risk of critical fire weather
conditions. A stout cold front moves through the region on Monday,
bringing much cooler conditions to the forecast area. Temperatures
warm rapidly in the wake of the front with conditions remaining
dry through at least Thursday, with increasing potential for
moisture late in the week.

&&

.SHORT TERM (Through 12Z/6AM Tuesday)...With a broad trough
currently in place over the PacNW region, dry and increasingly
strong southwesterly flow remains in place over the forecast area.
As such, fire weather conditions continue to be the main concern
over the next 36-48 hours primarily over the southern and eastern
portions of Utah. As of 0330, overnight relative humidity values
have struggled to increase over southern and eastern Utah, where
values have been noted anywhere from 7 to 20 percent. For some
areas, we may not see much of a change between now and the peak
heating of the day as far as humidity is concerned. Regardless,
increasing southwesterly flow will help bump afternoon wind gusts
up by 5 to 10 mph as compared to yesterday across southern and
eastern Utah, increasing the overall risk of critical fire weather
conditions. Red Flag Warnings remain in effect for areas with
critically dry fuels. Across northern Utah, winds will be a bit
more tame today as a more stable airmass lingers from a weak front
that pushed through that area yesterday. The cooler airmass over
northern Utah will help to maintain cooler temperatures across
this area through the day... about 5-7 degrees cooler than
Saturday.

Speaking of cooling temperatures, as we move into Monday, the
broad trough will dig deeper into the western U.S. and push a
dry cold front across the forecast area. Models continue to
converge on the most likely timing of this cold frontal passage,
but most guidance indicates that this front will progress through
the northern half of the area starting Monday morning through the
early afternoon, then progress through the southern half through
the late evening hours. Winds are likely to peak just ahead of the
frontal boundary, where peak gusts may approach the 45 mph mark
across portions of southern and eastern Utah. The duration of
winds are not anticipated to warrant any headlines, however, roads
running perpendicular to the winds (north-south oriented) may
experience difficult driving conditions. In addition, pockets of
blowing dust will be possible where top soil is dry and loose.

Winds in the post frontal environment will be generally slower,
however, given the density change of the airmass, thinking that
winds may continue to gust upwards of 30 to 35 mph for a short
period following the frontal passage. Downsloping/ canyon winds
will be very possible for areas on the lee side of mountain ranges
and canyons (e.g. areas on the southern and eastern side of
mountains) late Monday/ early Tuesday. Of particular interest will
be the SR-10 corridor from Fremont Junction through Price, where
there is a 25% chance of winds gusting over 40 mph, and 10%
chance of winds gusting over 55 mph. Will need to monitor trends
in the high resolution models through the next 12-24 hours.

.LONG TERM (After 12Z/6AM Tuesday)...In the wake of Monday`s
frontal passage, a much cooler and more stable airmass will
temporarily reside across the forecast area. Clearing skies Monday
night along with this much colder airmass will allow min temps to
fall near freezing across portions of the Wasatch Back and
potentially the Cache Valley as well, and Freeze headlines may be
needed if this trend holds. Max temperatures Tuesday afternoon
will run nearly 15F below climo across northern Utah, where highs
will struggle to reach the 70F mark across the northern valleys.
Further south temperatures will run closer to 10F below climo,
with upper 80s to low 90s across the lower elevations of southern
Utah.

A mean trough axis will remain situated to the west of the forecast
area throughout the middle to latter portion of next week, leaving
the forecast area under a mild and dry southerly flow aloft. Max
temperatures will quickly rebound to near climo Wednesday, then
continue to trend a few degrees warmer each day from Thursday into
next weekend. Additionally, moisture being pulled into the southern
and central Rockies may gradually spread west during the latter
portion of next week, allowing for a small chance for showers and
thunderstorms mainly over the far eastern CWA.

&&

.AVIATION...KSLC...VFR conditions will prevail through the TAF
period. Winds will maintain a northerly component throughout the
day, with a 30% chance of a period of light and variable winds
during the 11-15Z timeframe. Winds will become southeast after 03Z
this evening, before a cold front crosses the terminal around 09Z
tonight turning winds back to the northwest.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail
across the region throughout the day. A cold front will bisect the
area, with gusty southwest winds across southern Utah, and somewhat
lighter winds across northern Utah.

&&

.FIRE WEATHER...A broad trough remains in place over the Pacific Northwest
region, allowing for continued hot, dry, and windy southwesterly
flow over Utah. Today, surface winds are expected to increase by 5
to 10 mph as compared to yesterday, increasing the overall fire
weather risk over a more widespread area as these winds combine
with single digit relative humidity in southern and eastern Utah.
Red Flag Warnings remain in effect for zones with critically dry
fuels, however, the danger of critical fire weather conditions is
not limited to these areas. Overnight recoveries are expected to
be poor once again, ranging from 15-30% across the southern half
of Utah, and 30-50% across the northern half of Utah.

A stout dry cold front is expected to push through the region on
Monday, progressing across the northern half of the area from the
mid-to-late morning through the afternoon, and across the southern
half of the area from the afternoon through the late evening
hours. Ahead of this frontal boundary, winds are expected to
remain elevated and may even increase by another 5 mph as compared
to Sunday. With the frontal progression, winds will shift to a
northwesterly direction and may continue to gust upwards of 30-35
mph. On a positive note, the cooler overnight temperatures will
help many areas see much better recoveries in overnight humidity.
That said, the dry nature of the cold front is not expected to
have much of an effect on the daytime minimum humidity on Tuesday.
As such, afternoon minimums are still expected to fall into the
upper single digits to mid-teens. Hot and dry conditions prevail
through at least Thursday, with potential for increasing moisture
by Friday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning from noon today to 9 PM MDT Monday for UTZ495-
     496.

     Red Flag Warning until 3 AM MDT Tuesday for UTZ498.

     Red Flag Warning from noon today to midnight MDT Monday night
     for UTZ497.

WY...None.
&&

$$

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

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http://weather.gov/saltlakecity