Heat Advisory 3, NWS Reno, NV

362 
WWUS75 KREV 010306
NPWREV

URGENT - WEATHER MESSAGE
National Weather Service Reno NV
806 PM PDT Wed Jun 30 2021

CAZ070-071-NVZ004-005-010415-
/O.CAN.KREV.HT.Y.0003.000000T0000Z-210701T0500Z/
Surprise Valley California-Lassen-Eastern Plumas-
Eastern Sierra Counties-
Western Nevada Basin and Range including Pyramid Lake-
Northern Washoe County-
Including the cities of Cedarville, Eagleville, Fort Bidwell, 
Portola, Susanville, Westwood, Sierraville, Loyalton, Fernley, 
Fallon, Lovelock, Silver Springs, Nixon, Imlay, Empire, 
and Gerlach
806 PM PDT Wed Jun 30 2021

...HEAT ADVISORY IS CANCELLED...

The hottest conditions have ended but above average temperatures 
will persist through the Independence Day Weekend and into next 
week. Therefore safety precautions may still be needed, 
especially for those most sensitive to heat illnesses.

$$

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

Area Forecast Discussion
National Weather Service Reno NV
304 AM PDT Wed Jun 30 2021

.SYNOPSIS...

Above normal temperatures continue into the weekend. Increased
moisture from the Gulf of California will bring appreciable chances
for showers and thunderstorms each day through Saturday. Drier air
and westerly breezes look to return next week.

&&

.DISCUSSION...

HOT TEMPERATURES CONTINUE THROUGH THE HOLIDAY WEEKEND:

Temperatures will begin to decrease marginally as the upper-level
ridge responsible for the record heat wave over the Pacific
Northwest lifts northeast into Alberta-Saskatchewan and another
upper ridge located over the Central Plains shifts near the Four
Corners region. Temperatures will still be in the upper 90s to
triple digits across the lowest valleys of western Nevada and
upper 80s to low 80s for Sierra valleys. Widespread heat risks
begin to decrease today--although radiative cooling will be
limited, keeping overnight lows warmer than normal. Therefore the
Excessive Heat Warning was downgraded to a Heat Advisory through
this evening.

Heat health risks for sensitive groups could continue into the
Independence Day weekend as afternoon highs linger in the upper
90s to low 100s in the lower valleys of western Nevada and 80s in
most of the Sierra valleys. Cloud cover from thunderstorms may
mitigate afternoon high temperatures and increase overnight lows
compared to what is in the forecast.

* Continue to hydrate, stay in air-conditioned buildings, limit your
  exposure to the sun, and check on relatives and neighbors. Never
  leave young children or pets unattended in a vehicle.

THUNDERSTORMS BECOMING THE MAIN WEATHER THREAT THROUGH SATURDAY:

Southeasterly mid-level flow along the edge of the ridge over the
Rockies/Four Corners will continue to advect subtropical moisture
northward into western Nevada and the Sierra through Saturday.
Convection will continue to entrain mid-level moisture into the
boundary layer each afternoon and evening contributing to the
already increased PWATs. This increased moisture will enhance
thunderstorm coverage and chances each day areawide through
Saturday.

* If you have outdoor plans this Independence Day weekend, have a
  plan B and quick access to shelter if thunder roars.

Light deep-layer flow and high freezing levels may cause localized
flash flooding beneath stronger thunderstorm cores. Keep an eye on
recent burn scars and steep terrain for rapid debris flows near
thunderstorm cores. Thunderstorms will also produce strong outflow
winds, hail, big temperature drops, and possibly some new fire
starts. For more information on the impacts to the fire weather
community, see the fire weather section below.

DRYING POSSIBLE BY EARLY NEXT WEEK:

By Sunday, a trough may begin to approach the West Coast, allowing
more stable-dry southwest flow to develop across northern California
and northwest Nevada. This could either push thunderstorms out of
the region or at least contain them to areas near and south of US
50. Afternoon breezes may begin to increase as early as Sunday,
which could create choppy conditions on area lakes toward the end of
the Independence Day weekend.

-Johnston

&&

.AVIATION...

Temperatures will ease the rest of the week as the upper ridge
shifts east and moisture/cloud cover increase.

Thunderstorms chances will focus on an area from Reno-Pyramid Lake,
and over much of Storey-Lyon counties southward to the Eastern
Sierra. Chance of thunderstorms include 40% at KMMH, 15-20% at
KTVL/KTRK and 30% at KCXP/KRNO. Isolated thunderstorms will be
possible across much of western NV as well.

Strong and erratic outflow winds to 40 kts will be possible with any
storms with a short period of larger scale outflow winds (gusts to
30 kts) pushing out from the eastern Sierra into western NV early to
mid evening (roughly 00Z-04Z). Like Tuesday, these strong outflows
may produce areas of blowing dust across the Basin and Range,
possibly impacting KNFL/KLOL. Hohmann

&&

.FIRE WEATHER...

Thunderstorms continue through the end of the week and turn
increasingly wet. A few fire starts are always possible with
lightning, but the bigger threat will be heavy rainfall and possible
debris flows on local burn scars.

Simulations are showing drier southwest winds and a decrease in
storms sometime early next week. Dry winds after a few days of
lightning may allow hold-over fires to emerge. Best advice for now,
be prepared for a extended period of thunderstorms through the
weekend followed by drying and a return to the afternoon/evening
zephyr breezes next week.

Hohmann

&&

.REV Watches/Warnings/Advisories...
NV...Heat Advisory until 10 PM PDT this evening NVZ004-005.

CA...Heat Advisory until 10 PM PDT this evening CAZ070-071.

&&

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