894
FXUS65 KSLC 162154
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
354 PM MDT Mon Jun 16 2025

.SYNOPSIS...Red Flag conditions remain in place across southern
and eastern Utah through midnight tonight. Cooler temperatures
spread over the area on Tuesday with dry conditions remaining in
place. Increasingly hot and dry conditions spread across the
forecast area through the second half of the week, bringing
increased concerns of heat and fire weather risk.


&&

.SHORT TERM (Through 12Z/6AM Wednesday)...As of 345PM MDT, a
shortwave trough is noted over the western Great Basin region,
contributing to increased southwesterly winds across much of Utah
and southwest Wyoming. Extremely dry conditions at the surface
paired with these strong southwest winds have created widespread
critical fire weather conditions across the southern half and
eastern half of Utah. A Red Flag Warning remains in effect through
midnight for these areas. See the "Fire Weather" section of the
AFD for more fire weather related discussion.

A dry cold front associated with this shortwave trough is
anticipated to progress from north to south across the forecast
area from the mid-evening through the early morning on Tuesday. As
such, afternoon high temperatures tomorrow are expected to be
quite a bit cooler than today. Areas across northern Utah will see
a more substantial cooling than the southern area... daytime highs
across the north will fall more in line with climatological
normals while areas in the south remain about 3-6 degrees above
normal for this time of year.

.LONG TERM (After 12Z/6AM Wednesday), Issued 359 AM MDT...
High pressure to the
southeast will retrograde to off the Pacific coast near the coast of
southern California and Baja California with a trough and associated
cold front tracking through Tuesday. This will result in Wednesday
being much less windy than earlier in the week. Flow will be zonal
to southwest as the ridge tracks east Wednesday to near the Arizona
and New Mexico border.

The ridge to the southeast will strengthen Thursday, while a
longwave trough will approach the PacNW. This will result in enhanced
southwest flow for much of the western U.S. For southwest Wyoming
and Utah, this set up, with minimum relative humidity into the
single digits and teens, will bring high fire danger. In addition,
forecast temperatures are in record territory for the date for much
of southwest Wyoming and Utah. The National Blend of Models 25th-
75th percentile for high temperature at KSLC is 104-106F.
Probabilistic data suggests roughly a 90% chance that the date`s
record of 101F will be exceeded. Forecast highs for the urban
corridor of northern Utah generally range from 100-102F, with the
warmest conditions up to 110F throughout lower Washington County.

Ensembles are in good agreement on the track of the aforementioned
longwave trough, with it to track to near the coast later Friday.
That will result in similar conditions through Friday. The ridge to
the southeast will track slightly east, with slightly cooler
temperatures around 5F off of Thursday. Relative humidity will
remain very low and winds will increase.

The longwave trough will approach from the northwest Saturday. The
biggest uncertainty is with timing. It is likely that at least
southern Utah will continue with much warmer than normal, dry
conditions with gusty southwest winds. Depending on timing of the
cold front, gusty soutwest winds could continue for southwest
Wyoming and much of Utah.

There is high confidence that the longwave trough and associated
cold front will track through southwest Wyoming and most of Utah by
the end of the weekend. It will be a dry storm system, but bring
strong cold air advection. Highs will go from the 90s for most
valleys Friday and Saturday to the 70s Sunday. The cooler conditions
will bring a slight increase in relative humidity. Northwest winds
behind the front will be much lighter than the southwest winds ahead
of it from Thursday into Saturday.

&&

.AVIATION...KSLC... Winds are expected to calm somewhat following
00z as they continue to transition to predominately northwesterly to
around 5kts by 06-07z. Winds will be light and variable through the
evening, though should remain mostly northwesterly into the morning.
During the day tomorrow, winds pick up once again out of the
northwest to around 10-12kts following 15z.

.AVIATION...REST OF UTAH AND SOUTHWEST WYOMING... All sites are
expected to shift to northwesterly this evening following the
passage of a dry frontal boundary with winds tapering off through
the overnight. Regarding KBCE, a fire is currently ongoing to the
southwest. In the next few hours, smoke could begin to settle
reducing ceilings and/or reducing visibilities overnight at the
terminal. There is some uncertainty surrounding this, so amendments
will likely be needed. Tomorrow afternoon, gusty northwest winds
will resume across all sites.

&&

.FIRE WEATHER...A dry low pressure system moves through Utah today,
bringing with it a widespread increase in windspeed and a dry
cold front to follow. The dry cold front is expected to progress
from north to south across the area from early Monday evening
across the northern area and into the southern area by 0600 to
0800 on Tuesday morning. Ahead of the frontal boundary, expect
deep atmospheric mixing to bring unstable conditions alongside
strong southwesterly flow (gusts to 30-35 mph). A Red Flag Warning
remains in place through midnight tonight as strong winds and dry
conditions remain in place. Northwesterly flow with reduced wind
speeds (peak gusts 15-20 mph) is expected across the region
tomorrow alongside cooler conditions. That said, afternoon
relative humidity will remain critically dry across Utah which,
when combined with a little afternoon breeze, will create areas of
elevated fire weather conditions.

High temperatures return to a warming trend by Wednesday as
southwesterly flow spreads back over the region. An offshore
trough is expected to develop once again through the latter half
of the week, bringing a significant increase in dry, southwesterly
flow across much of Utah. Afternoon wind gusts are expected to
fall in the 30-40 mph range for much of the central and southern
portions of Utah, and will combine with an extremely dry surface
environment (RH less than 10%). Critical fire weather conditions
are likely from Thursday through at least Saturday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning until midnight MDT tonight for UTZ482-489-
     492>498.

WY...None.
&&

$$

SHORT TERM...Webber
LONG TERM...Wilson
AVIATION...Worster
FIRE WEATHER...Webber

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