Flash Flood Warning 1, NWS Las Vegas, NV

625 
WGUS75 KVEF 110814
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1214 AM PST Sat Mar 11 2023

CAC027-110824-
/O.EXP.KVEF.FF.W.0001.000000T0000Z-230311T0815Z/
/00000.U.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Inyo CA-
1214 AM PST Sat Mar 11 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 1215 AM PST EARLY THIS MORNING 
FOR WESTERN INYO COUNTY...

Flooding is no longer expected to pose a threat in the upper 
drainages of Big Pine Creek near the Sierra crest.

A Flood Watch remains in effect for the Owens Valley until 500 AM 
PDT Sunday.

LAT...LON 3712 11858 3713 11858 3711 11842 3704 11842
      3704 11844 3705 11844 3706 11844 3707 11845
      3707 11847 3708 11849 3710 11850 3709 11851
      3710 11852 3711 11853 3711 11854 3711 11857
      3712 11857

$$

JA

Area Forecast Discussion
National Weather Service Las Vegas NV
157 PM PST Fri Mar 10 2023

.SYNOPSIS...Rain and high elevation snow will continue in the Sierra
Nevada and Owens Valley today, with light scattered rain showers
spreading eastward across the Mojave Desert this afternoon. Gusty
southwest winds will continue through the evening. Conditions will
improve through the weekend with clear skies and above average
temperatures. Next week, another atmospheric river will return
precipitation chances to the region.
&&

.SHORT TERM...Today and Saturday.

Southeastern California continues to experience light to moderate
rainfall this afternoon thanks to an atmospheric river aimed at the
coast. Warm wind coupled with rain-on-snow will accelerate snow melt
in the Sierra Nevada, where extremely above-average snowpack exists.
In this morning's AFD update, we mentioned a couple of ways the
forecast was slightly off track. (1) Snow levels started off lower
than expected, with Mammoth Yosemite Airport (around 7100 feet)
consistently observing snow. An observer located in Aspendell around
8500 feet has noted wet snow with about a 2:1 ratio all morning. In
the forecast update, went with 5th percentile snow levels to better
align with observations. (2) More moisture spilled over the Sierra
Nevada into the Owens Valley than anticipated. As of 1:45pm PST,
Bishop Airport has received 1.89 inches of rain since the start of
the event, allowing it to break daily rainfall records for the site.
As such, with the forecast update, increased QPF a bit for the Owens
Valley this afternoon. The bulk of the precipitation has occurred,
but can expect another 0.10 to 0.30 inches in Bishop with higher
amounts in southern Inyo County where the highest radar reflectivity
returns of the day are ongoing. Widespread flooding has been
observed in the Owens Valley, with US-395 closed from Bishop south
to the Inyo / Kern County line. Areal Flood Warnings exist along
this route where 2 to 3 feet of water and debris have been reported
on side roads.

The Flood Watch remains in effect for the eastern Sierra Slopes and
the Owens Valley through 4am PST Sunday. Though precipitation will
largely cease past the Sierra this evening, flooding will continue
to be a concern over the next 24-36 hours as run off and snow melt
inundates washes.

In addition to flood concerns, the Winter Storm Warning for the
Sierra Nevada and Winter Weather Advisory for the White Mountains
continue through 4am PST Sunday due to persistent snow accumulations
above 7000 feet.

Through the afternoon and evening, moisture will spread eastward
across the forecast area, increasing PoPs over the southern Great
Basin and Mojave Desert. Valley rainfall totals will remain less
than a tenth of an inch, but higher elevations can see upward of a
half inch. The exceptions are the panhandle of Lincoln County where
the HRRR continues to highlight a robust band of precipitation
setting up late this afternoon and the Spring Mountains, where
upslope dynamics could produce 1-2 inches of rainfall this
afternoon. There is some question in precipitation type on the
Spring Mountains due to the uncertainty in snow levels, but largely
expecting rain below 8000 feet.

Skies will clear west-to-east tonight and Saturday, allowing
afternoon temperatures to warm to above-average across the region.

.LONG TERM...Sunday through Thursday.

Sunday and Monday look like a break in the atmospheric river
action, with zonal flow transitioning to flat ridging and limiting
precip chances to the Sierra and the northern fringes of the CWA,
with minimal to no impact expected. Expect locally gusty westerly
winds in the favored terrain areas such as Barstow and the
Sierra, but not looking like advisory level at this time.

The next AR is still targeting our area Tuesday and Wednesday. On
the positive side, snow levels look a bit lower, hovering around
8000 feet during the heaviest precipitation, and dropping to 5000
to 6000 feet on the back side of the storm. Another round of very
heavy precip is likely for the Sierra, with liquid equivalent
totals of about six inches at the crest. Snow ratios around 12:1
would suggest about six feet of snow at the crest, with a bit less
at the resort level. Barring a significant change in either storm
track or snow levels, Winter Storm Warnings will be needed. Low
pressure passing by to the north on Wednesday (a bit slower than in
previous model runs) should generate enough forcing for some light
precip in the deserts.

There is quite a bit of model spread for Thursday, with solutions
ranging from ridging overhead in the wake of the storm to low
pressure lingering overhead for one more day. Regardless,
impactful weather looks unlikely. Of note, Monday and Tuesday
could be the warmest days since about November 1st for much of the
Mojave Desert. This will promote more mountain snow melt,
possibly keeping creeks and rivers swollen.
&&

.AVIATION...For Harry Reid...South to southwest winds with
occasional gusts to around 25-30 kts will continue through the
afternoon and early evening before diminishing to around 10-20
kts. There is some indication during the overnight and early
Saturday morning period that winds could decrease even more than
forecast and be under 10 kts. If this occurs, the likely timeframe
would be between between 08z and 15z. Southwest winds are
forecast to increase once again after 17z Saturday with speeds
between 10-15 kts and gusts to around 25 kts. There may be a few
showers around into this evening, but the majority will remain
over the higher terrain. CIGS are expected to be around 6k feet
with gradual improvement this evening and overnight.

For the rest of southern Nevada, northwest Arizona and southeast
California...Significant precipitation will continue through the
afternoon across Inyo County with the KBIH seeing low CIGS and
occasional mod-heavy precipitation. Rain chances will diminish this
evening across Inyo County, but lower CIGS are expected to remain
overnight into Saturday along with isolated showers. Elsewhere, look
for CIGs generally around 6k feet or lower with widespread mountain
obscurations. Some improvement overnight, but still remaining at 8k
feet or lower. South to southwest winds 10-20 kts with gusts to
around 30-40 kts over most areas into this evening with winds
diminishing somewhat this evening.
&&

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

SHORT TERM...Varian
LONG TERM...Morgan
AVIATION...Gorelow

For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
526 PM PST FRI MAR 10 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     AVALANCHE        2 E ASPENDELL           37.23N 118.56W
03/10/2023                   INYO               CA   PUBLIC

            SEVERAL SMALL AVALANCHES REPORTED NEAR
            HABEGGER LANE.

&&

SM