960
FXUS65 KREV 040950
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
250 AM PDT Thu Sep 4 2025

.KEY MESSAGES...

* Shower and thunderstorm chances continue through Friday, mainly
  for the Eastern Sierra and the Nevada Basin and Range. A very
  low risk for heavy rain persists south of I-80.

* Areas of smoke and haze continue to locally impact visibility and
  air quality due to fires in the Sierra.

* Cooler temperatures and increasing winds are expected this
  weekend into early next week.

&&

.DISCUSSION...

A few very light showers in the fringes of the CWA remain as of 2
AM this morning from yesterday`s activity. Otherwise, there are
no significant impacts at the moment besides patchy fog in the
Martis Valley.

This afternoon, showers and thunderstorms return to portions of the
Eastern Sierra in Mono County and extending into Mineral county.
However, probabilities remain below 25%. The other area of concern
today will be over northern Washoe, eastern Lassen and the
Surprise Valley with similar probabilities. The main hazards
remain gusty winds, small hail, lightning, and periods of
moderate to heavy rain. The risk for flash flooding remains below
5% today.

Storm chances increase tomorrow with a quick bump in PW rising to
0.5-0.7 inches in the NV Basin and Range. PWs west of US-95
remain mostly below 0.5 inches. Instability increases too as well
as an improvement in the dynamics aloft with the approach of
another shortwave trough. This trough will push the moisture east
by the end of Friday. But before that happens, rain and storm
chances increase Friday PM to 20-45% east of US-95, and remain
around 10-20% east of 95.

The weather pattern turns drier this weekend as we remain at the
base of the storm track. However, for us conditions become cooler
along with increasing winds through early next week. NBM guidance
continues a trend of covering more areas with a 30-70% chance of
max gusts greater than 30 mph, especially on Saturday and Monday.
Temperatures will continue their descend this weekend to around 5
degrees below normal, and by next week afternoon highs will be
around 10 degrees below normal due to more upper level systems
reaching our region. These lower than normal temperatures also
mean that portions of the Sierra may reach morning lows below
freezing. Plus there are some low chances of precipitation with
those systems that could lead to some flurries if the pattern
observe occurs by mid-week.

-HC

&&

.AVIATION...

Mostly VFR conditions are expected through the Friday morning.
Smoke concerns form CA wildfires may affect portions of the
southern Sierra/Mono county. Otherwise, slantwise VIS reductions
for areas south of US-50. Showers and thunderstorms return to
portions of Mono/Mineral after 18Z with a 20% chance of affecting
KMMH and KHTH, and a 10-20% chance from Black Rock Desert to the
Surprise Valley. Periods of MVFR conditions are possible with any
storm.

Patchy fog continues in the vicinity of KTRK through 15Z this
morning, and another shot tonight between 09Z-15Z. Although
shallower if there is no rain this afternoon. There is less than
10% chance of rain too.

-HC

&&

.FIRE WEATHER...

Shower and storm activity is low today between 10-25%, and mostly
confined to areas south of US-50 and over northern Washoe and the
Surprise Valley. Tomorrow, chances increase but the main concern
will be east of US-95. Any storm may be capable of dry lightning
away from rain cores, brief periods of heavy rain, and gusty
outflow winds.

This weekend, a cooler and breezier pattern returns with the approach
of another upper trough. This pattern could lead to isolated elevated
fire concerns in mountain ridges and over NW NV and NE CA. Currently,
NBM guidance keeps a 30-70% chance of wind gusts exceeding 30 mph
through the weekend and early next week in the aforementioned areas.
These winds could fan out any new holdover fires from the
thunderstorms this week.

-Jim/HC

&&

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

$$