Severe Thunderstorm Warning 3, NWS Reno, NV

Area Forecast Discussion
National Weather Service Reno NV
120 PM PDT Thu Aug 8 2019

.SYNOPSIS...

Showers and stronger thunderstorms will continue into this
evening bringing gusty winds, hail, and heavy rain. A few storms
remain possible Friday and Saturday, but the focus will shift into
northeast California and northern Nevada. Breezy conditions
Friday and Saturday will give way to below normal temperatures
this weekend. Warmer and drier conditions are likely for next
week.

&&

.DISCUSSION...

Main concern continues to be thunderstorms today followed by breezy
conditions Friday and Saturday. Chances for showers and
thunderstorms were added to the forecast on Saturday for
northeast California as forecast models have trended a bit farther
east with the moisture in the trough.

* Today: A shortwave is lifting into the Sierra and western Nevada
  this afternoon, which is triggering thunderstorm development.
  The 18z KREV special sounding showed excellent midlevel lapse
  rates along with CAPE values around 1500 J/kg, with no lingering
  cap, which is why storms have developed quickly this afternoon.
  With a decent midlevel jet in place (though the core is more
  into eastern Nevada), there is the shear necessary to bring
  better organization to ongoing storms. This means that
  stronger/severe storms are possible, with strong and erratic
  outflow winds up to 50 mph, and hail up to 1" in diameter. With
  moisture increasing, storms look to be efficient rain producers,
  so locally heavy rain is likely, despite the fact that storms
  will be moving 15-25 mph. If storms backbuild over the same
  location or become stalled over terrain, we could have flash
  flood concerns, especially if steep terrain or burn scars are
  involved.

* Friday/Saturday: Moisture will be on the decrease, however there
  is enough lingering moisture and instability for isolated storms
  to once again develop across portions of northeast California
  and northern Nevada. These storms will be fast moving, with 30
  mph in the storm bearing layer, so once again, dry lightning
  strikes is possible. The other concern will be increasing winds
  as a deep area of low pressure moves inland. Widespread gusts
  of 25-30 mph are possible Friday and Saturday, with locally
  stronger winds, especially north of I-80. This brings fire
  weather concerns, especially if any new ignitions take place.
  Please see the fire section below for additional details. Winds
  will likely bring turbulence for aviation as well as choppy
  conditions to area lakes.

Saturday and Sunday will be significantly cooler, with high
temperatures 7-10 degrees below normal. Seeing some spotty frost
Sunday morning in sheltered mountain valleys would not be surprising
either as lows drop to freezing. A few showers and thunderstorms are
possible in northeast California Saturday, due to the trough, but
most activity should be north and west of the region. Otherwise, a
warming and drying trend is expected the first half of the week with
typical afternoon breezes. By the end of next week, ensemble
guidance are in good agreement that another trough will move into
the west with the return of increased winds. -Dawn

&&

.AVIATION...

Thunderstorms will continue to develop this afternoon mainly near
and east of Highway 395, moving eastward this evening. Storm
locations may change as outflows can produce new cell development.
Terrain obscuration is likely along with gusty and erratic outflow
winds in excess of 40 mph, localized heavy rainfall, and hail.
Stronger and more organized storms are possible into the central
Nevada Basin and Range eastward this afternoon.

Chances for storms to reach terminal sites today:

KRNO/KCXP/KMEV: 25%
KTVL/KTRK: 15%
KMMH: 60%
KNFL: 70%

Breezy conditions to follow Friday and Saturday, which may bring
turbulence and localized areas of wind shear. Isolated storms remain
possible across northeast California into northern Nevada Friday,
with a few showers in northeast California Saturday. -Dawn

&&

.FIRE WEATHER...

Another round of strong thunderstorms have developed today with
widespread lightning strikes likely. However, storms today are
expected to produce heavy rain along with those lightning strikes.
Storms could also produce hail up to 0.5-1" and gusty outflow
winds up to 40-50 mph.

Fire weather concerns continue for Friday and Saturday afternoons.
By Friday afternoon the large area of low pressure will be just off
the coast of northern California. This will act to enhance the
afternoon zephyr winds both Friday and Saturday with widespread
gusts of 25-30 mph. Both relative humidity and winds will be
borderline on Friday with isolated critical fire weather
conditions possible, especially in northern Washoe and eastern
Lassen counties. To further complicate the situation there is also
a chance of isolated thunderstorms, potentially on the dry side,
in that same region. However, none of these elements currently
look widespread enough for Red Flag Warnings.

By Saturday, the low pressure is forecast to move into northern
California and northwest Nevada. Winds are expected to be similar
on Saturday, but cooler temperatures are expected to keep humidity
values above critical thresholds by then. One change to the forecast
for Saturday is that we could see a few more storms in NE
California and extreme NW Nevada as the low pressure moves into
that region.

Temperatures will be much cooler over the weekend with drier and
warmer conditions returning early next week. For the long range,
there is another low pressure likely approaching the region by the
end of next week. -Zach

&&

.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
1206 PM PDT Thu Aug 8 2019

CAZ072-073-NVZ001>004-082100-
Greater Lake Tahoe Area CA-Mono CA-
Western Nevada Basin and Range including Pyramid Lake NV-
Greater Lake Tahoe Area NV-Greater Reno-Carson City-Minden Area NV-
Mineral and Southern Lyon Counties NV-
1206 PM PDT Thu Aug 8 2019

...STRONG THUNDERSTORMS CONTINUE FOR THIS AFTERNOON AND EVENING...

Doppler radar continues to track strong thunderstorms mainly for
areas south of US-50, including the eastern Sierra. Heavy rain,
nickel sized hail, cloud-to-ground lightning and winds in excess of
40 mph will be possible with these storms. This development is
expected to continue into the early evening hours before the storms
begin to dissipate.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

During a thunderstorm, seek shelter inside a sturdy structure and
stay away from windows. Hikers and campers should seek shelter in a
vehicle if possible.

&&

LAT...LON 3758 11901 3774 11913 3773 11925 3788 11920
      3795 11932 3804 11931 3820 11963 3845 11968
      3881 12003 3885 12016 3942 12037 3948 11762
      3935 11777 3910 11778 3900 11819 3889 11817
      3847 11770 3789 11842 3747 11783 3746 11878
TIME...MOT...LOC 1858Z 240DEG 0KT 3864 11917

EL

Special Weather Statement
National Weather Service Reno NV
112 PM PDT Thu Aug 8 2019

NVZ002>005-082215-
Western Nevada Basin and Range including Pyramid Lake NV-
Greater Lake Tahoe Area NV-Northern Washoe County NV-Greater Reno-
Carson City-Minden Area NV-
112 PM PDT Thu Aug 8 2019

...Strong Thunderstorms Developing over Northwestern Nevada...

At 110 PM PDT, Doppler radar was tracking a strong thunderstorms
over Washoe County Nevada, moving northeast at 20 mph.

Dime size hail, frequent hail, and wind gusts up to 50 mph will be
possible with this storm. This development is expected to continue
into the early evening hours before the storms begin to dissipate.

Locations impacted include...
Reno, Carson City, Pyramid Lake, Lahontan Reservoir, Incline Village,
Gerlach, Virginia City, Sparks, Fernley, Dayton, Spooner Summit,
Wingfield Springs, Northwest Reno, Spanish Springs, Golden Valley,
Virginia Peak, Carson City Airport, Verdi-Mogul, New Washoe City and
Hidden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If on or near Pyramid Lake, get out of the water and move indoors or
inside a vehicle now. Don't be caught on the water in a
thunderstorm. Strong wind gusts and lightning pose an immediate
danger to boaters. Gusty winds will cause a rapid increase in wave
heights which may capsize small boats.

Heavy rainfall is occurring with this storm. Expect ponding of water
on roadways. In areas of steep terrain, minor rock slides are
possible. Drivers should slow down and turn on their headlights if
encountering heavy rains.

&&

LAT...LON 4096 11933 4096 11901 3919 11900 3923 11914
      3910 11930 3909 11997 4198 11996 4198 11932
TIME...MOT...LOC 2010Z 219DEG 17KT 3985 11970

AH