Special Weather Statement, NWS Reno, NV

Area Forecast Discussion
National Weather Service Reno NV
324 PM PDT WED APR 27 2016

.SYNOPSIS...

The weather will remain unsettled through Thursday with scattered
showers and isolated thunderstorms expected. Drier conditions and
milder temperatures are expected for Friday with another low
pressure system possible by Friday night, lasting through the
weekend. This system has the potential to bring cooler
conditions, gusty winds, and showers to the region.

&&

.SHORT TERM...

An area of low pressure is moving into northern California and the
Sierra this afternoon. Scattered showers are initially forming in
northeast California and the Sierra, where partial clearing took
place behind this morning's warm air advection. Instability is
marginal over the area, but better dynamics are expected to move
into the area later this afternoon, as evidenced by the current
radar activity in the central CA valleys and western Sierra
slopes. Still, expect that thunderstorm activity will be fairly
isolated in coverage.

Snow levels are currently running around 6500-7500 feet, so light
snow showers or snow pellet showers are possible over some of the
Sierra passes this afternoon and evening. However, these storms do
not have the moisture or forcing needed to produce enough pellets
to keep roads covered and it's likely that any impacts will only
last 30 minutes to an hour at most. With these storms being
convective (showery) in nature, expect precipitation accumulation
to be hit or miss. Many areas will see more or less than what is
currently forecast.

This low quickly exits the region Thursday with precipitation
chances mainly limited to areas south of I-80 and east of Highway
95. Drier and warmer conditions are expected Friday, but this will
be short-lived as another fast moving area of low pressure drops
into the region Friday night. This system has had relatively poor
model agreement the past several days, but most recent forecast
runs and ensembles are now in better agreement in a more westerly
track. This will lead to cooler conditions along with chances for
showers and possibly even thunderstorms Friday night into Saturday
across the Sierra and western Nevada. In addition, gusty north to
northeast winds are expected on Saturday, bringing choppy
conditions to area lakes in addition to making it feel that much
colder across the region. -Dawn

.LONG TERM...Sunday through Wednesday...

By Sunday the core of low pressure is expected to move into the four
corners region leaving western Nevada on the periphery of any
remnant moisture. A few light showers will remain possible on
Sunday, mainly in Mono County, as moisture banks up against the
Eastern Sierra.

On Monday shortwave ridging will briefly build over the Sierra
most likely bringing warmer temperatures and clearing skies.
There remains some uncertainty of how fast the low pressure will
eject and whether enough remnant moisture will be left over to
create the possibility afternoon thunderstorms. The EC ejects the
low and moisture more quickly and has been handling the synoptic
evolution much better lately in the 5-6 day period, so will stick
with the dry solution on Monday for now.

Ridging will be short-lived as most model simulations develop
another trough of low pressure along the California coast by
Tuesday. There remains a lot of uncertainty of how this low will
develop and when it will bring a return of precipitation. Currently
looks like a splitting low pressure, so predictability with this
system may remain difficult for the next few days.

Bottom line - anyone looking forward to sudden shift to warm and dry
Spring conditions is going to have to wait a little longer. -Zach

&&

.AVIATION...

An area of low pressure is now over central California where
radar shows the highest concentration of thunderstorm activity. A
few thunderstorms have developed in the Sierra and in far western
Nevada in Lyon/Douglas counties with additional storms possible
this afternoon and evening. Chances for thunderstorms at or in the
vicinity of KTRK are 50 percent, while at KTVL, KCXP, KRNO, and
KMMH, they are 30 percent. Thunderstorm chances are expected
through about 03z, while showers may persist overnight, especially
south of Interstate 80.

The greatest risk from thunderstorms will be lightning in addition
to pellet showers and lowering ceilings/visibility which could
obstruct surrounding terrain. Pellets may briefly accumulate on
Sierra runways if the shower is heavy enough, but will quickly
melt off with any impacts lasting less than 30 minutes.

In general most terminals will see light west winds gusting to
around 20 kts with erratic and stronger gusts near storms.
-Zach/Dawn

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

For more information from the National Weather Service visit...
http://weather.gov/reno

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RENO NV
510 PM PDT WED APR 27 2016

CAZ071-280045-
LASSEN-EASTERN PLUMAS-EASTERN SIERRA COUNTIES CA-
510 PM PDT WED APR 27 2016

...STRONG THUNDERSTORM WITH HAIL NORTH OF SUSANVILLE...

AT 508 PM PDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
2MILES NORTH OF SUSANVILLE...OR 14 MILES SOUTHEAST OF EAGLE LAKE.
THIS STORM IS MOVING SOUTHWEST AT 5 MPH.

SMALL HAIL...WHICH MAY ACCUMULATE ON HIGHWAYS...AND WINDS TO 40 MPH
WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
SUSANVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM WILL AFFECT TRAVELERS ON CALIFORNIA 139 BETWEEN
SUSANVILLE AND 5 MILES NORTH OF SUSANVILLE. DRIVERS SHOULD EXPECT
STRONG GUSTY CROSS WINDS...WITH RAPID VISIBILITY REDUCTIONS. HEAVY
RAINFALL WILL RESULT IN PONDING OF WATER. SLOW DOWN WHEN
ENCOUNTERING HEAVY RAIN AND TURN ON YOUR HEADLIGHTS.

&&

LAT...LON 4069 12038 4041 12038 4041 12076 4069 12076
TIME...MOT...LOC 0008Z 057DEG 4KT 4048 12059

JW