Permanente, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

393
FXUS65 KVEF 211613
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
813 AM PST Thu Nov 21 2024

.SYNOPSIS...Dry conditions will continue through Friday with a
gradual warming trend. A broad low pressure system over the Pacific
Northwest will slowly sag southward and direct moisture into the
Southern Sierra Friday night and Saturday followed by widespread
breezy and cooler conditions along with chances of rain and mountain
snow expanding across our region Sunday into early next week.
&&

.UPDATE...Quiet morning across the region. Mostly clear skies with
just a few high clouds streaming across the area. The current
forecast is on track and no updates are planned this morning.
&&

.PREV DISCUSSION...108 AM PST Thu Nov 21 2024...

.SHORT TERM...Today through Friday.

Dry and tranquil weather will continue across our forecast area
today through Friday as we reside under weak southwest flow aloft
between the large Pacific Northwest low and a ridge axis centered
over the Rockies. Some mid and high clouds will drift overhead on
the south side of the atmospheric river streaming into Northern
California. High temperatures will climb 3-4 degrees each day and
winds will remain light and variable for most zones except Friday
afternoon in the Southern Sierra and Esmeralda/central Nye
counties where winds will begin to increase as the Pacific
Northwest system slowly digs.

.LONG TERM...Saturday through Wednesday.

The upper-level ridge will increase afternoon temperatures to around
5 degrees above-average on Saturday before a potent trough sags from
the Pacific Northwest, effectively squashing the ridge for the
foreseeable future. This trough will result in a relatively zonal
flow across the forecast area as it ushers in warm atmospheric
moisture. Numerous perturbations will pass through the upper-level
flow through the long term period, resulting in persistent slight
precipitation chances and breezy afternoons. That said, as a result
of the moisture`s trajectory, the bulk of it will smack into the
western side of the Sierra Nevada Mountain Range, causing a rain
shadow over the majority of the forecast area. This is more evident
in the newer model runs, as precipitation chances and forecast
precipitation amounts have dropped substantially in the last 24
hours.

Some precipitation spill over can be expected in the eastern Sierra
slopes, the White Mountains, and the Owens Valley, but again,
chances have dropped. Formerly the Owens Valley had about a 20%
chance of receiving 2 inches of precipitation from this event.
Currently, there is a 30-35% chance of the Owens Valley - including
Bishop - to receive around 1 inch. In addition to valley rain, we
can expect eastern Sierra snowfall, with snow levels between 6000
and 7000 feet resulting in 1-2 feet of snow on the peaks. Best
precipitation chances outside of Inyo County exist in the
southeastern Great Basin where 50-60% chance exists. For those
hoping for rain to break our dry streak (currently 130 days) in the
Las Vegas Valley, Las Vegas has around a 20% chance of measurable
rainfall Sunday through Tuesday. We will continue to assess how much
moisture (if any) will make it over the Sierra and into the Mojave
Desert through the weekend and first half of next week to determine
related impacts for the region.

Outside of precipitation, gusty west-southwest winds will pick up
across the region on Saturday, with strongest winds down the eastern
Sierra slopes (potentially resulting in downslope winds reaching the
Owens Valley floor) as well as the western Mojave Desert. There is a
60-70% chance of gusts exceeding 40 mph on the northern side of the
Spring Mountains on Saturday as well, which could result in
hazardous crosswinds along Highway 95 west of Indian Springs.
&&


.AVIATION...For Harry Reid...Expect similar wind patterns to
yesterday with very light winds following typical wind patterns
through Friday morning. Wind speeds will remain under 8KT through
the period, favoring the east today then becoming southwest after
sunset then becoming light and variable late tonight and Friday
morning. VFR conditions with FEW-SCT clouds around 25kft possible at
times.

Looking ahead- A storm system will bring increasing southwest winds
and the chance of precipitation to the region Saturday into Monday.
The strongest winds are expected Saturday afternoon with a high
probability (70% chance) for wind gusts over 25KT and a low chance
(30% probability) for wind gusts over 35KT. Wind gusts of 15-25KT
are expected Sunday into Monday. The best chance for rain at the
terminal will be Sunday afternoon, though rain will be possible in
and around the area late Saturday night through Monday. Any nearby
precipitation could result in CIGs under 10kft and mountain
obscuration to the west.

For the rest of southern Nevada, northwestern Arizona, and
southeastern California...Light winds will persist through the
morning at all locations. Breezy south-southeast are possible at
KBIH this afternoon as gusts to around 15KT could develop after 18Z
and persist until around sunset when winds will diminish and become
light and diurnal after 03Z. North winds at KIFP could also briefly
gust to 20KT between 18Z-00Z this afternoon. Otherwise, Light and
diurnal wind patterns are expected across much of the region through
Friday morning. Occasional FEW-SCT around 20kft are possible at
times, especially at KBIH this afternoon as clouds stream off the
Sierra.
&&

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

&&

$$

UPDATE...Wolcott
SHORT TERM...Adair
LONG TERM...Soulat
AVIATION...Nickerson

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