363
FXUS65 KVEF 171958
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1258 PM PDT Tue Sep 17 2024

.SYNOPSIS...The next system will drops into the region mid- to-
late week, which will reinforce below- average temperatures and
return precipitation chances to the southern Great Basin. Conditions
dry out once again through the weekend as temperatures rebound
back to near average.
&&

.SHORT TERM...Through Friday.

Low impact weather will continue tonight and Wednesday morning
before the  next system drop in from the Pacific Northwest Wednesday
afternoon.This potent system will move through the region Wednesday
night through Friday, bringing a chance for precipitation across
much of the region as it does do.

Overall, not much as changed form the previous forecast from this
system other than a slight slow down with the onset of precipitation
Wednesday afternoon. A few light showers may move into Esmeralda and
northern Inyo County Wednesday late afternoon, otherwise the rest of
the region will remain dry Wednesday. Overnight Wednesday, the focus
of precipitation and impacts will be in Esmeralda and Inyo County
where increasing diffluence aloft will provide enough forcing for
precipitation to develop. Slightly above normal moisture will be in
place over that area, however normal PWATs at this time of the year
are around 0.50 inch so there wont be this robust moisture pool for
significant precipitation to occur. In fact, moisture looks similar
to what was in place on Monday when showers and isolated
thunderstorms streamed through Esmeralda County- and no impacts were
reported from that round of precipitation. The greatest chance for
impacts Wednesday night will be in the Sierra and Whites of Inyo
County as model reflectivities hint at precipitation train along the
terrain as they stream northward.

The upper level low will push eastward Thursday. There continues to
be some discrepancy between models to the strength and positioning
of the system, with the center of the low Thursday afternoon sitting
somewhere in south-central California into western Nevada. This is
important as cold core dynamics may come into play near the center
of the low. The highest risk for cold core enhancement Thursday
afternoon will be in Inyo, Esmeralda, and central Nye counties where
a majority of the models show slightly negative LIs and very low end
CAPE. Eastern and southern areas like Mohave County, the Colorado
River Valley, and much of San Bernardino County should remain dry
Thursday as moisture will be low and forcing will be focused further
west. Precipitation chances will spread into those areas Thursday
night and Friday, however the upper level system should be weakening
therefore the risk of precipitation and impacts will be lower.
Overall through the entire event, the probability for impactful
precipitation amounts is low. There is over a 50% probability for at
least some rain (over 0.1 total from Wednesday night through Friday
afternoon) in northern Inyo through Esmeralda County with
probabilities decreasing as you go south and east. The probability
for impactful rainfall totals of 0.5 inch or 1.00 inch over the same
the entire event is 10% or less for the entire area. So overall, not
expecting widespread significant impacts from this system. Snow
levels will remain around 9000ft or higher through the event so any
snow will be confined to the very high elevations. Snow accumulation
totals will be only a few inches in those areas and winter storm
severity levels barley climb into the minor impact levels for the 3
day total. WInds will not be of significant concern with the
trajectory of the center`s low and lack of thermal gradient keeping
winds below impactful levels.

Temperatures Wednesday and Thursday will warm slightly compared to
today but will still remain well below normal for this time of the
year.

.LONG TERM...Saturday through Monday.

As the low traverses our area, instability associated with the
cold temps aloft should fuel scattered showers and thunderstorms.
Saturday looks like the day with the most uncertainty, as most
model perturbations show the low center off to our east, but a
sizable minority depict a slower movement and leave it lingering
over our area for one more day. If the faster movement pans out,
Saturday would be dry with several degrees of warming; if the
slower solutions verify better, we would expect less warming and
one more day of showery weather. As high pressure builds in from
the west, Sunday and Monday should be dry and warm, with
temperatures close to normal for mid September.
&&

.AVIATION...For Harry Reid...Winds will remain light, less than 10
knots, and will follow typical diurnal directional trends.

For the rest of southern Nevada, northwest Arizona and southeast
California...Winds at the remaining Las Vegas Valley TAF sites will
remain light, less than 10 knots, and will follow typical diurnal
directional trends. KBIH will swing around to the south and pick up
later this afternoon before shifting to the north in a typical
diurnal fashion later this evening. KDAG will favor a westerly
direction with 15 to 20 knot wind gusts beginning during the early
evening hours and continuing through tomorrow morning. Winds at KEED
will remain light and variable. KIFP will favor a southerly to
southeasterly direction with sustained speeds o f10 knots or less.

&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

$$

SHORT TERM...Nickerson
LONG TERM...Morgan
AVIATION...Stessman

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