306
FXUS65 KREV 122122
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
222 PM PDT Wed Jun 12 2024

.SYNOPSIS...

Well above normal temperatures will continue through the week with
chances of showers and storms south of the Tahoe Basin today and
Thursday. Critical fire weather conditions are likely Friday
afternoon. Cooler and drier weather is favored this weekend into
next week.

&&

.DISCUSSION...

Another hot June day is well underway with temperatures in 80s and
90s for Sierra communities and western Nevada valleys, respectively.
Latest satellite observations reveal cumulus maturing from Mono
County into S Lyon and Mineral counties, an area in which a 10-15%
chance of showers and isolated thunderstorms exists through sunset.

A weak upper cyclone will slowly drift from the southern California
bight towards the lower Colorado River valley Thursday, allowing for
diffluent flow to overspread portions of the Sierra. The overlap of
large scale ascent and intense surface heating will increase chances
of afternoon showers and thunderstorms to 20-40% for areas south of
US-50 and west of US-95. Showers and thunderstorms that develop here
may drift northeastward across Mineral and Churchill counties in the
late afternoon and evening.

The synoptic regime Friday and over the weekend will feature western
troughing, which will provide steady cooling and periods of breezy
winds. A belt of enhanced 700mb flow will overspread the Sierra and
western Nevada on Friday, yielding increased west to southwest winds
with gusts of 25-35 mph Friday afternoon. Some wind prone locales
may see gusts upwards of 40 mph at times. As such, choppy lake
waters, bumpy flights, and difficult driving conditions for high-
profile vehicles are likely. Furthermore, gusty winds may support
several hours of critical fire weather conditions. Please refer to
the Fire Weather section below for more details.

The 12Z suite of ensembles favor western troughing for the first
half of next week, which will maintain mild temperatures and low
chances of showers and storms.

-Salas

&&

.AVIATION...

Widespread VFR conditions and gusty afternoon winds will prevail
today with the primary weather concern being afternoon showers and
isolated thunderstorms in the vicinity of KMMH. Chances of a
thunderstorm within 10 miles of KMMH is 10-15% through around 02Z.
Otherwise, density altitude issues may persist through the week
before temperatures cool this weekend.

-Salas

&&

.FIRE WEATHER...

A multi-hour period of critical fire weather conditions is becoming
increasingly likely for the Sierra Front, N Washoe County, and the
Basin and Range on Friday afternoon. Sustained west to southwest
winds of 15-20 mph with gusts of 25-35 mph will overlap with daytime
humidities of 10-15% and abundant sunshine for a 3-6 hour window in
the afternoon Friday. Overnight recoveries will be quite poor Friday
and over the weekend as RH struggles to exceed 40% for valley floors
to the mid-slopes of western Nevada. Per latest fuel intel from
partners, receptive fine fuel beds exist in portions of the Basin
and Range and below 6500 feet across the Sierra Front, but a sub-
critical fuel status will likely preclude a greater fire concern
in N Washoe County.

Elevated to locally critical fire weather conditions may develop
Saturday and Sunday afternoon, but strongest winds will be much
weaker and more localized compared to Friday.

-Salas

&&

.REV Watches/Warnings/Advisories...
NV...Fire Weather Watch from Friday afternoon through Friday evening
     NVZ420.

     Fire Weather Watch from Friday afternoon through Friday evening
     NVZ423.

CA...&&

$$