Severe Thunderstorm Warning 11, NWS Reno, NV

Area Forecast Discussion
National Weather Service Reno NV
224 PM PDT Mon Jul 20 2020

.SYNOPSIS...
Primarily isolated afternoon and evening showers and thunderstorms.
Thunderstorm coverage and intensity will increase Tuesday and
Wednesday as low pressure nears the West Coast. The potential for
showers and thunderstorms will decrease late week. Plan for light
winds outside of afternoon zephyr breezes and any outflow winds from
thunderstorms.

&&

.DISCUSSION...
Three primary concerns this week.
*Smoke/Haze from ongoing wildfires
*Thunderstorms: increasing in coverage and intensity
*Ongoing Heat.

-SMOKE/HAZE-

Visibility reductions along with air quality impacts will continue
as the Hog wildfire actively burns west of Susanville. Haze and
smoke from this fire will continue to saunter around the region, as
there are no strong transport winds to direct it elsewhere. Only
relief has been with mixing in the afternoon along with any outflow
winds from thunderstorms to assist with clearing out smoke/haze. For
updates on air quality check with your local air quality management
district or go to airnow.gov.

-THUNDERSTORMS-

If you have outdoor plans, complete them earlier in
the day than usual for a summer day. Some simulations have
thunderstorms kicking off as early as 11am for Tuesday and
Wednesday.

Thunderstorm pattern will persist through the week with the
potential for storms to become more widespread and potentially more
intense each day. This afternoon and evening will be another more
typical thunderstorm day, but Tuesday and Wednesday is the time
frame that warrants more concern and attention.

Trough edges into northern California on Tuesday afternoon resulting
in increased southerly flow as well as cooling temps aloft that will
allow for more conducive conditions for thunderstorm development. As
the low continues to push slowly eastward across the region, there
will be sufficient instability and moisture to produce thunderstorms
from Tuesday afternoon-evening, with another round of storms
possible overnight, and an early start to thunderstorms on Wednesday
midday. Generally speaking when we have a trough sweeping across the
western states in July, this raises concerns for elevated
thunderstorms across the region. Elevated, drier storms are a big
concern for fire weather, so check out the fire weather discussion
for more information on that. Upper forcing will help produce more
organized storms on Tuesday and Wednesday with a longer lifespan as
opposed to the more popcorn type storms of the past few days.

-HEAT-

Typical July heat will persist through Tuesday with above average
daytime highs and warmer than "comfortable" overnight lows. Many of
us in western Nevada and portions of NE CA won't be sleeping with
windows open for the next several nights because of the smoke
anyways. As a trough comes into the region, temperatures will begin
to moderate and cool a touch by Wednesday into the weekend. Only
other potential for cooler temperatures will be those
afternoon/evening thunderstorms. For example, Carson City airport
hit 99 degrees yesterday and then quickly cooled off in the wake of
a thunderstorm into the low 70s! Reno airport, not so much, but
maybe today!

&&

.AVIATION...
Smoke and haze from the Hog wildfire west of Susanville will
continue to impact surface visibility to areas in close proximity to
the fire (including KSVE at times). Plan for poor to moderate
slantwise visibility across much of northeast CA-northwest NV.

Thunderstorms will remain possible in the afternoon and evening
for the next few days. Heavy rain, hail, and outflow winds over 40
kts will be possible. Coverage will generally be along and south
of RNO-TRK southward to Mono County/far western Mineral County
today. More widespread thunderstorm coverage is likely Tuesday and
Wednesday, with stronger storms also possible as low pressure moves
into northern California. A few storms may persist and develop
Tuesday night into Wednesday. Late day zephyr breezes are expected
to be weak each day through midweek, likely disrupted (or locally
enhanced) by storm outflows. MJD/Edan

Chances for thunderstorms within 10 miles of area terminals:
Values are for Today - Tuesday - Wednesday

KTRK = 20% - 25% - 30%
KTVL = 25% - 30% - 40%
KMMH = 35% - 35% - 35%
KRNO = 20% - 30% - 30%
KCXP = 20% - 30% - 35%
KMEV = 20% - 30% - 40%

&&

.FIRE WEATHER...

***MIX OF WET AND DRY THUNDERSTORMS EXPECTED THE NEXT COUPLE DAYS***

* We have issued Red Flag Warnings for Tuesday across Western Nevada
  and much of northeastern California, including Lake Tahoe and the
  Sierra Front. A Fire Weather Watch was also issued for Wednesday
  for the same areas.

* Monsoonal moisture continues to creep up from southern Nevada,
  bringing unstable conditions to our area. We will see isolated
  to scattered thunderstorms through this evening, mainly along
  the Sierra east of Highway 395, stretching from Mono County all
  the way into Lassen, including the Hog Fire. A few new lightning
  starts are possible for today, but storm motions will be very
  slow and most areas will see rainfall. Heads up for gusty
  outflow winds up to 40 mph today with any storms.

* Low pressure off the California Coast will move further inland,
  with cooler temperatures aloft increasing instability. This will
  create more widespread thunderstorm coverage by Tuesday. As the
  low pressure moves even further inland on Wednesday, this will
  increase the wind shear aloft making for potentially severe
  thunderstorms on Wednesday. As storm motions increase Tuesday into
  Wednesday, this will create more opportunity for dry lightning.

* Storms will be a mix of wet and dry, meaning that some areas will
  see heavy rainfall while others see little to no rainfall and new
  wildfire starts from dry lightning. Due to the recent above normal
  temperatures and dry conditions, vegetation is especially
  receptive to lightning starts right now.

* Threats from thunderstorms on Tuesday and Wednesday will include
  large hail, strong outflow winds up to 60 mph, and localized
  heavy rainfall that could produce flash flooding in steep
  terrain and over recently burned areas. -Hoon

&&

.REV Watches/Warnings/Advisories...
NV...CA...Dense Smoke Advisory until 11 AM PDT Tuesday CAZ071.

&&

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

Special Weather Statement
National Weather Service Reno NV
545 PM PDT Mon Jul 20 2020

CAZ072-NVZ002-210145-
Greater Lake Tahoe Area CA-Greater Lake Tahoe Area NV-
545 PM PDT Mon Jul 20 2020

...Thunderstorms and gusty winds will continue to impact Lake
Tahoe...

At 542 PM PDT, Doppler radar was tracking a strong thunderstorm over
Carnelian Bay, or near Kings Beach. This storm was nearly stationary.

Winds in excess of 40 mph will be possible with this storm and can
capsize small watercraft. Outflow winds from this storm could reach
all the way to the southern shore of Lake Tahoe.

Locations impacted include...
Lake Tahoe, Carson City along Lake Tahoe, South Lake Tahoe, Kings
Beach, Tahoe City, Incline Village, Bliss State Park, Incline
Village-Crystal Bay, Glenbrook, Zephyr Cove, Crystal Bay, Carnelian
Bay, Sugar Pine Point S, Emerald Bay, Zephyr Cove-Round Hill
Village, Homewood, William Kent Campground, Stateline, Dollar Point,
Meeks Bay and Tahoe State Rec Area Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If on or near Lake Tahoe, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3926 11991 3906 11993 3895 11994 3893 12007
      3911 12019 3924 12009
TIME...MOT...LOC 0042Z 000DEG 0KT 3921 12008

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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
558 PM PDT MON JUL 20 2020

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

0515 PM     HAIL             INCLINE VILLAGE         39.25N 119.96W
07/20/2020  E0.88 INCH       WASHOE             NV   PUBLIC

            NUMEROUS REPORTS OF HAIL UP TO NICKEL SIZE
            AROUND INCLINE VILLAGE. HAIL LASTED UP TO 20
            MINUTES IN PARTS OF TOWN.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
559 PM PDT MON JUL 20 2020

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

0507 PM     HAIL             KINGS BEACH             39.24N 120.03W
07/20/2020  E0.25 INCH       PLACER             CA   PUBLIC

&&

Special Weather Statement
National Weather Service Reno NV
608 PM PDT Mon Jul 20 2020

NVZ003-004-210200-
Western Nevada Basin and Range including Pyramid Lake NV-
Greater Reno-Carson City-Minden Area NV-
608 PM PDT Mon Jul 20 2020

...Gusty Winds to impact Pyramid Lake...

At 605 PM PDT, Doppler radar was tracking a thunderstorm outflow 9
miles north of Spanish Springs, or 16 miles northeast of Reno. This
gust front was moving northeast at 30 mph.

Winds in excess of 40 mph will be possible with this storm. Gusts
this strong could capsize small watercraft or loft unpinned
inflatables.

Locations impacted include...
Pyramid Lake, Nixon, Sutcliffe, Virginia Peak, Spanish Springs, The
Needle Rocks and Dogskin Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If on or near Pyramid Lake, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3967 11968 3980 11987 4022 11968 4025 11953
      3985 11933 3972 11945
TIME...MOT...LOC 0105Z 240DEG 0KT 3975 11970

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