985
FXUS65 KVEF 180815
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
115 AM PDT Wed Sep 18 2024

.SYNOPSIS...A trough of low pressure will swing across the western
US during the second half of the week, bringing a slight chance of
precipitation to the southern Great Basin and reinforcing the
below-normal temperatures. Drier and warmer conditions will return
over the weekend as a high-pressure ridge builds over the region.

&&

.SHORT TERM...Today through Friday.

A trough of low pressure currently off the Oregon coast will
continue to move south today along the California Coast. Dry
weather is expected area-wide through this afternoon. However, by
this evening, the approaching trough will result in enough
difluence aloft to produce a few showers over Esmeralda and
northern Inyo counties. Moisture will still be limited with PWATs
of .50" to .60", so no significant precipitation is expected to
fall.

The trough will continue to move south on Thursday before moving
inland over southern California Thursday night and across the CWA
on Friday. This timing is a bit slower than the previous forecast,
with the best chance of precipitation now expected Thursday night
and Friday. Given the cold-core nature of this system, there is
the potential for weak convection to develop as the center of the
low passes Friday. Right now, the best chances for this are across
southern Inyo, Nye, Clark, and northern Mohave counties, where
CAPE values of 200-400 J/kg are forecast. However, moisture will
continue to be limited over the area, with most of it being
intercepted by the Sierra. The probability of impactful
precipitation amounts of 0.50 inches is less than 30 percent,
mainly over the higher elevations of Inyo and Esmeralda Counties
Thursday night and northern Lincoln County on Friday. The chance
of seeing 1.00 inch or more for the entire event is near zero
area-wide. Snow levels will be 9000ft or higher through Friday, so
any snow that does fall will be confined to high elevations of
the Sierra and White Mountains where a few inches will be
possible. It is also not out of the question that the highest
peaks in the Spring Mountains could see their first dusting with
this system. No impactful winds are forecasted through the end of
the week.

Temperatures will warm slightly today when compared to Tuesday
but still remain about 10 degrees below normal for this time of
year. Readings will then fall a few degrees by Friday as the base
of the trough swings across the region.

.LONG TERM...Saturday through Tuesday. Picking up Saturday morning,
model consensus is for the low to be exiting stage right, with any
lingering precip chances limited to the eastern fringes of our CWA.
As the low departs, the warming trend will begin, and high temps
should be five to 10 degrees warmer Saturday than Friday, except in
the far eastern CWA where clouds and precip chances will hold temps
down one more day. Dry weather then takes hold for the rest of the
period as high pressure builds in from the west, and highs rise
another four to eight degrees from Saturday to Monday before
plateauing on Tuesday. No significant winds are expected through the
period.

&&

.AVIATION...For Harry Reid...Generally light winds favoring diurnal
trends are expected through mid afternoon with just a few clouds AOA
20kft. There is a brief window for southeasterly winds of 8 to 12
knots between 23z-4z before the winds transition back to the
southwest after sunset.

For the rest of southern Nevada, northwest Arizona and southeast
California...Most areas across the Mojave Desert and Colorado River
Valley will observe another day of fairly light winds with mostly
sunny skies.  Exception will be near the Sierra and Owens Valley
with breezy southeast winds expected near KBIH this afternoon that
will ease after dark. Increasing clouds and shower activity are also
expected near KBIH, mainly after 23z and persisting into Thursday.

&&

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

&&

$$

SHORT TERM...Planz
LONG TERM...Morgan
AVIATION...Outler

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