376
FXUS65 KSLC 310945
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
345 AM MDT Thu Jul 31 2025
.SYNOPSIS...High pressure will bring seasonably hot and very dry
conditions to Utah and southwest Wyoming through at least early
next week. Breezy winds will bring critical fire weather
conditions to central and southern Utah today, with the threat
being limited to the higher terrain Friday into the weekend as
winds decrease.
&&
.SHORT TERM (Through 12Z/6AM Saturday)...The amplifying ridge is
centered over the Desert Southwest early this morning, with the
trough over the Great Basin lifting north over the top of it.
Though southwest flow prevails across the area, the position of
the surface low over northwest Utah has put far northern Utah and
southwest Wyoming under easterly flow with a decent surface
pressure gradient. Despite the lack of cold advection, seeing some
downslope winds in prone areas of the Cache Valley and eastern Box
Elder county, with some isolated gusts in excess of 40 mph. Winds
are also gusty out of the east in parts of southwest Wyoming.
Guidance indicates this surface low weakening over the next few
hours, so these winds should be on a downward trend.
Otherwise, conditions are generally tranquil this morning with
just a few light showers over Castle Country associated with some
ejecting shortwave energy that will tend to diminish as sunrise
approaches. Seasonably hot and very dry conditions continue across
the entirety of Utah and southwest Wyoming, and with southwest
winds remaining enhanced due to the presence of the trough,
central and southern Utah will see another day of critical fire
weather conditions. Weak cold advection has already begun with the
trough lifting northward, so temperatures will be a few degrees
less warm then yesterday, near normal for this time of year. A
weak and dry cold front associated with the trough will cross
northern Utah tonight into early Friday, knocking highs down a
degree or two for tomorrow. As the trough exits the area, winds
will relax enough to limit critical fire weather conditions to the
central and southern mountains for tomorrow.
The exiting trough will provide just enough moisture and
instability for some isolated high based showers and thunderstorms
over far northwest Utah this afternoon/evening as well as Friday.
Additionally, with the flow aloft veering just a bit, a small
amount of moisture will move into southeast Utah, bringing the
potential for isolated storms there as well. Like with the last
few days, any storms that develop will produce little if any
rainfall, but will have the potential to produce gusty and erratic
winds.
.LONG TERM (After 12Z/6AM Saturday)...The long-term period will
begin generally quiescent as the region remains under the influence
of a broad ridge and dry southwesterly flow. Despite these dry
conditions, a weak upper-level disturbance moving into the Great
Basin on Saturday will allow some isolated showers and thunderstorms
to develop during the afternoon across far northwestern Utah. Dry
microbursts will be the main threat, given extremely dry lower
levels. Ridging builds back in across the region on Sunday, cutting
off potential for any additional shower activity.
The pattern turns a bit more active early next week as a shortwave
trough digs into the Great Basin on Monday. This system will
introduce increased southwesterly flow across the region, resulting
in heightened fire weather concerns on Monday afternoon. See the
fire weather section below for additional details. Ensembles are
supportive of a Four Corners high developing as early as Tuesday,
which would allow moisture to be drawn up into the region from the
south. As such, could see afternoon shower and thunderstorm chances
returning as early as Tuesday, especially across southern Utah.
&&
.AVIATION...KSLC...VFR conditions to prevail through the
period. Light southeasterly winds are expected to increase after
roughly 16z this morning. Southerly winds with gusts 20-25 kts are
possible through around 00z ahead of a dry frontal passage that
brings northwesterly winds thereafter.
.REST OF UTAH AND SOUTHWEST WYOMING...Easterly downslope winds are
expected to continue through around 10z for KOGD-KLGU-KEVW, with
gusts upwards of 40 knots possible at times. Otherwise, generally
light winds prevail for all other regional terminals this morning.
Enhanced southerly winds develop after roughly 16z across the
region, with gusts ranging between 20-30 kts through this afternoon.
A mostly dry cold front tracking into northwest Utah will allow
winds to transition more westerly to northwesterly this afternoon
and evening for northern Utah terminals. Some isolated showers
developing across far northwest Utah may lead to gusty outflows that
could create more erratic winds this afternoon.
&&
.FIRE WEATHER...The trough over the Great Basin will lift northward
over the ridge parked over the central United States through this
evening. Conditions will stay seasonably hot and very dry, with
the influence of the trough keep winds breezy across much of the
area. This will result in another day of critical fire weather
conditions, focused over central and southern Utah. As the trough
exits, winds will relax a bit for Friday over the weekend. Still,
winds will be strong enough for critical fire weather conditions
to persist for the mountains of central and southern Utah. Winds
will start to increase again beginning Sunday as another trough
approaches, raising the fire danger once again.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning until 10 PM MDT this evening for UTZ489-492-495-
497-498.
Red Flag Warning from noon today to 10 PM MDT this evening for
UTZ483-484-494.
Red Flag Warning until 10 PM MDT Saturday for UTZ493-496.
WY...None.
&&
$$
SHORT TERM/FIRE WEATHER...Traphagan
LONG TERM/AVIATION...Whitlam
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity
