684
FXUS65 KREV 212143
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
243 PM PDT Mon Jul 21 2025

.KEY MESSAGES...

* Gusty winds will impact recreation and travel today, and pose
  critical fire weather conditions in western Nevada.

* Daily chances of showers and thunderstorms are expected into the
  weekend with best chances on Thursday.

* Cooler than normal temperatures will prevail across the region for
  the rest of the week.

&&

.DISCUSSION...

Atypically strong low pressure resides in the Pacific Northwest
latest moisture-channel imagery with an attendant cold front draped
across NE California and far NW Nevada. An increase in cloud cover
and even light showers accompany the cold front, giving some areas
of quick taste of autumn.

Winds continue to increase ahead of the cold front with gusts
reaching 30-40 mph this afternoon before subsiding in the
evening. As a result, waters will be choppy on area lakes this
afternoon, along with impacts to air/ground travel. These winds
will also overspread low RH in western Nevada, resulting in
critical fire weather conditions this afternoon (more details
below).

An area of weak low pressure will detach from the mean flow and
meander near the N California coast after today. Minimal change in
the weather pattern will keep the region beneath moist air aloft,
which will support daily chances of showers and thunderstorms
Tuesday into the weekend. The most favorable days are Wednesday
through Friday when odds reach 20-30% near the Oregon border and in
the Mono-Alpine-Mineral County vicinity. Abnormally high PWATs favor
wetter thunderstorms in Lassen and N Washoe counties with a mix of
wet and dry farther south where drier air resides. Otherwise, the
rest of the week will be cooler than normal as daytime highs near 80
and 90 degrees in Sierra and western Nevada communities,
respectively.

-Salas

&&

.AVIATION...

The main weather concern will be gusty west winds this afternoon for
all terminals, which may pose low-end LLWS concerns into the early
evening -- especially for KRNO-KCXP-MEV. A southward advancing cold
front will continue to increase mid to high level cloudiness at
Tahoe and Sierra Front terminals with light showers, but VFR
conditions will largely prevail today. Thunderstorm impacts will
become more likely for the remainder of the week.

-Salas

&&

.FIRE WEATHER...

A cold front is progressing farther south than previously
advertised, which is increasing humidity above critical thresholds
for portions of the northern Sierra Front. Winds will likely be
strong enough to compensate and maintain fire concerns in this
region. 3-6 hours of critical fire weather conditions is still on
track in the W NV Basin and Range where the cold front hasn`t
modified the existing dry airmass. Expect an improvement in
overnight recoveries tonight away from lowest valleys in western
Nevada.

After today, daily chances of thunderstorms will prevail into the
weekend and increase the potential for lightning ignitions. Storms
are trending on the wetter side as of now, but dry lightning will
still be possible with the drier storms and/or outside of main rain
cores.

-Salas

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory until 11 PM PDT this evening NVZ001>004.

     Red Flag Warning until 10 PM PDT this evening NVZ420.

     Red Flag Warning until 10 PM PDT this evening NVZ423-429.

CA...Lake Wind Advisory until 11 PM PDT this evening CAZ071-072.

&&

$$