Avalanche in Utah, February 11, 2024

Area Forecast Discussion
National Weather Service Salt Lake City UT
329 AM MST Sun Feb 11 2024

.SYNOPSIS...A dry westerly flow will bring a gradual warming
trend across the region through the upcoming week. The next round
of Pacific storm systems will begin to impact the region during
the upcoming weekend.

&&

.SHORT TERM (Through 12Z Tuesday)...A Pacific Northwest trough is
currently centered over New Mexico as a ridge makes its way into
the Great Basin. In between these two features, Utah and southwest
Wyoming is under a dry and generally stably northerly flow aloft
this morning. Over southwest Utah, a tight northerly pressure
gradient persists, resulting in some enhanced gap winds in prone
areas of Washington county. Given the lack of cold advection,
associated wind gusts are generally in the 20s but have seen
isolated gusts into the upper 30s. As the gradient relaxes during
the day, so will these winds. Also seeing a few pockets of low
clouds in lingering moisture left behind from the system, most
notably in the vicinity of Evanston. Would anticipate the areas of
low clouds to diminish during the morning.

Clear skies and the cold airmass from the trough will result in
noticeably colder temperatures this morning, particularly over
southern Utah. Apparent temperatures around Bryce Canyon National
Park are expected to bottom out at around -10F and Capitol Reef
National Park should see apparent temperatures in the upper single
digits, something to keep in mind for those with morning outdoor
plans at these parks. Maxes today will also be on the cool side,
around 5F below climo over northern Utah and more like 10F below
seasonal normals over southern Utah. The area will then see
noticeably warming by Monday as the flow aloft shifts to the west,
bringing some warm advection. Current forecast indicates maxes
near seasonal normals for most locations across Utah and southwest
Wyoming.

.LONG TERM (After 12Z Tuesday)...A rex block pattern with a large
ridge centered over the Gulf of Alaska and an area of low pressure
to its south will help keep a persistent zonal pattern across our
area through much of the period before a more progressive pattern
appears likely by next weekend. With the rex block pattern over the
eastern Pacific, a broad trough over Canada will keep a mostly
westerly flow across the Great Basin. Additionally, with the lack of
any substantial cold air advection temperatures will gradually warm
throughout the week.

A shortwave on Tuesday will move by to our north that could provide
some light snow showers across the high terrain of far northern
Utah. A more robust shortwave on Thursday will bring better chances
of precipitation across northern Utah as a baroclinic zone to our
north and enhanced moisture will aid in more widespread
precipitation. Snow levels will be flirting with valley floors
across far northern Utah where colder air aloft will help to pull
snow levels down. This activity will largely be confined to northern
Utah where better dynamics will favor more widespread ascent.

Chances have increased ~10% since yesterday's forecast regarding a
landfalling atmospheric river across California. Current guidance is
showing ~60-65% chance of an AR moving onto the west coast by next
weekend. The trajectory of this moisture remains uncertain with
guidance mainly split into two clusters: one cluster (55% chance)
brings this moisture further north into the PNW and across Idaho and
Montana, and the other cluster (45% chance) brings this moisture
into California and into the Great Basin. P-type will likely be a
concern near valley floors as mean H7 temperatures are ~-7C. Beyond
this first potential AR there exists a couple more opportunities for
more anomalously high moisture to stream into the western CONUS
going into the following week.

&&

.AVIATION...KSLC...VFR conditions will persist throughout the period
for the KSLC terminal. Dry conditions and only scattered high clouds
will exist with light southerly winds transitioning to light
northerly winds during the afternoon.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist
throughout the entire area with exception to SW Wyoming where
morning fog will keep conditions LIFR/IFR until the fog begins to
clear mid morning. Otherwise, dry conditions will encompass the area
with a few high clouds along with light and variable winds.

&&

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

SHORT TERM...Traphagan
LONG TERM/AVIATION...Mahan

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