Lakeview, Utah Weather Forecast Discussion

173
FXUS65 KSLC 061939
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
139 PM MDT Sat Sep 6 2025
.SYNOPSIS...Deeper moisture will remain in place through the
evening, with a drying trend commencing tonight into the early
part of the upcoming week. Moisture and instability will increase
during the middle to latter part of the upcoming week as a slow
moving trough approaches the area.
&&
.SHORT TERM (Through 12Z/6AM Monday)...With high pressure
flattening and shifting east, Utah and southwest Wyoming find
themselves under a zonal flow this afternoon, which is starting to
draw drier air into the area from the west. PWs remain on the high
side for area east of I-15 or so, with satellite derived PW values
in the 0.8 to 1.0 inch range for much of the area. The drier
intrusion is starting to show up over western Utah, however, as
evidenced by a rapidly increasing swath of PWs of 0.6 inch or
less.
Earlier cloud cover has been slow to erode, so despite ejecting
shortwave energy making its way across northern Utah, convective
initiation is just now beginning, primarily for areas on the edges
of that cloud cover. CAMs continue to show additional development,
primarily for areas east of I-15, through the afternoon,
diminishing rapidly during the early evening, earliest over
northern Utah with a more stable airmass developing in the wake of
the shortwave. Any storms that develop will be capable of
producing heavy rain capable of flash flooding, with the active
burn scars and slot canyons over eastern Utah looking like the
main threat areas. Gusty winds will also be possible with any
storms that develop.
Drier air will continue to move in overnight into Sunday, even as
the flow becomes a bit more southwesterly as the ridge re-
amplifies. Thus, convection tomorrow will be more isolated and
confined to northern and eastern portions of the forecast area
where the deeper moisture is expected to linger. Like today,
Sunday`s highs are expected to run near to a couple of degrees
below normal for this time of year.
.LONG TERM (After 12Z/6AM Monday), Issued 351 AM MDT...There is
really good model agreement that a longwave trough will be
positioned off the Pacific coast near the California and Oregon
border Monday. As this system approaches, a ridge will slide east.
The associated monsoonal moisture will diminish throughout
southwest Wyoming and Utah. Meanwhile, southwest flow east of the
trough axis will enhance. Southwest wind gusts will range from
15-25 mph for southwest Wyoming and southwest Utah.
Southwest flow will strengthen as the longwave trough slides into
the western U.S. Tuesday. Along with that will come drier
conditions. Minimum relative humidity values will generally range
from 10-20% for valleys. Wind gusts from around 20-30 mph with the
dry conditions will bring higher fire danger. Models are in good
agreement on isolated showers and thunderstorms for the northern
mountains as weak shortwave energy pushes through. These would be
high-based and more likely to produce gusty, erratic outflow winds
than much precipitation.
There are more differences in ensembles later into the week with
details on the trough. Most indicate it transitioning into a
closed low while remaining to the west. That would result in
continued windy conditions with isolated or scattered high-based
showers and thunderstorms. The trough would eject further east
Thursday or Friday, bringing cooler conditions and better
probabilities for measurable rainfall for southwest Wyoming and
most of Utah.
Temperatures early in the week will be around 5F warmer than
normal as the trough slides into the western U.S. As it
approaches, conditions will cool. The coolest temperatures will
likely be Thursday or Friday as the trough axis tracks into Utah.
High temperatures will be around 5-10F cooler than normal.
&&
.AVIATION...KSLC...VFR conditions will persist for the KSLC terminal
through the period. There is a 30% chance of thunderstorms through
~00Z before conditions dry out and clouds thin out through the
overnight. Any storms that approach the terminal will be capable of
producing gusty and erratic winds. Light northerly winds will
transition to light southerly winds overnight.
.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist
for the airspace through the period. Afternoon convection (~30%
coverage) across the central and eastern airspace will persist
through sunset before gradually diminishing overnight. Any storms
that do impact terminals will be capable of gusty and erratic winds.
Otherwise, mid and high level clouds will gradually diminish with
light and diurnally driven winds.
&&
.FIRE WEATHER...Moisture remains high over the state this afternoon,
but earlier cloud cover has been slow to erode so convection is
somewhat isolated. Will see increasing coverage of showers and
thunderstorms through the late afternoon, particularly for areas
east of I-15, with coverage decreasing significantly this evening.
The area will see a steady drying trend tonight through Tuesday.
Though a few showers will develop each afternoon, coverage will be
noticeably less than the past few days. Southerly flow will start
to increase early next week with an approaching trough, with
moisture increasing and temperatures dropping as this system
slowly moves through during the latter part of the upcoming week.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&
$$
SHORT TERM/FIRE WEATHER...Traphagan
LONG TERM...Wilson
AVIATION...Mahan
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http://weather.gov/saltlakecity

NWS SLC Office Area Forecast Discussion