153
FXUS65 KSLC 040948
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
348 AM MDT Mon Aug 4 2025

.SYNOPSIS...A hot and very dry southwest flow will set up across
the region through much of the week. A dry cold front may bring
some relief by the weekend.

&&

.SHORT TERM (THROUGH 12Z WEDNESDAY)...The axis of the upper ridge
has shifted east into Colorado overnight, allowing southwest flow
aloft to become established over Utah this morning. A shortwave
trough noted over Oregon will graze far northwest Utah late this
afternoon through this evening as it ejects northeast. This trough
will largely remain dry, but will help bring enhanced southwest
winds to Utah ahead of it. Widespread breezy conditions will
combine with the dry airmass in place to result in critical fire
weather conditions across the bulk of the forecast area today.

The shortwave trough will push a shallow, dry, cold front into
northwest Utah this evening. Temperatures across the north will
trend slightly downward tonight and tomorrow as a result.
Additionally, winds across northern Utah will be a bit weaker
tomorrow behind the departing trough, but remain breezy across
central and southern Utah, maintaining critical fire weather
conditions there.

.LONG TERM (After 12Z/6AM Wednesday)...Conditions will stay warm,
dry, and windy Wednesday. A strong ridge of high pressure will be
positioned to the southeast while a broad west to southwest synoptic
flow stays in place for much of the west. Winds will be similar to
prior in the week throughout southwest Wyoming and Utah, with gusts
generally ranging from 20-30 mph much of the afternoon. The enhanced
southwest flow will be dry, with minimum relative humidity values in
the single digits to teens. The combination of gusty winds and low
relative humidity will bring high fire danger. Valley high
temperatures will be in the mid or upper 90s for much of Utah, with
low 100s around Lake Powell and around 105F for lower Washington
County.

Minimal change will come Thursday with high pressure to the
southeast. A longwave trough will dig into the PacNW, which will
transition winds a bit more to the west. Temperatures will likely
cool slightly for southwest Wyoming and northern Utah and warm
slightly for the remainder of Utah.

The longwave trough will track into southwest Wyoming and Utah
Friday. There is uncertainty in precise timing, but high confidence
in a dry baroclinic zone tracking in from the north. The longwave
trough will graze to the north, with the most cooling for southwest
Wyoming and roughly the northern half of Utah. That will result in
cooler conditions with lighter winds for locations north of the
boundary, with more dry, windy conditions further south.

Valley high temperatures for Saturday will generally be in the mid
or upper 80s for locations where the front will track through, while
southern portions of Utah will have high temperatures in excess of
100F.

&&

.AVIATION...KSLC...Light southeast winds will increase, with gusts
around 20 knots from 15-19Z. Winds will transition to northwest with
lighter speeds around 20Z with scattered high clouds. Clouds will
clear through the evening with northwest winds transitioning to
southeast around 04Z.

.REST OF UTAH AND SOUTHWEST WYOMING...Mostly clear conditions with
relatively light winds will last through around 15Z. South to
southwest winds will increase after 15Z, with gusts from 20-30 knots
throughout southwest Wyoming and much of Utah through 03Z. Scattered
high clouds will build in by 18Z, then clear through the evening.

&&

.FIRE WEATHER...Southwest flow will settle over Utah today and
remain in place through late week. A weak but dry weather
disturbance grazing northwest Utah this evening will bring
increased winds to much of the area this afternoon and evening.
Combined with very low relative humidities into the single digits
in many areas this afternoon along with poor overnight recovery,
this will result in widespread critical fire weather conditions.
Winds will decrease across the north tomorrow but remain breezy
across central and southern Utah, maintaining critical fire
weather conditions in those areas. Midlevel moisture is expected
to increase somewhat across southern and eastern Utah mid to late
week. Relative humidities should recover slightly with the
moisture. While afternoon humidities may increase to around 15% or
higher in the mountains during the second half of the week,
valleys will likely continue to see low humidities which should
allow critical fire weather conditions to continue through late
week. A dry cold front may cross the region Saturday, with winds
trending weaker behind it.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning from noon today to 9 PM MDT this evening for
     UTZ478-479-481.

     Red Flag Warning from noon today to 9 PM MDT Wednesday for
     UTZ483-484-488-489-492-494-495-497-498.

     Red Flag Warning from noon today to 9 PM MDT Tuesday for UTZ482-
     493-496.

WY...Red Flag Warning from noon today to 8 PM MDT this evening for
     WYZ277.

&&

$$

Cheng/Wilson

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