786
FXUS65 KREV 162005
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
105 PM PDT Mon Sep 16 2024

.SYNOPSIS...

* Well-below average temperatures for today, with widespread rain
  showers and high elevation snow possible through the night.

* Another fall-like storm brings continued below average
  temperatures and additional precipitation chances Wednesday and
  Thursday.

* A warming and drying trend arrives just in time for the weekend.

&&

.DISCUSSION...

Regional infrared satellite this morning reveals a center of
circulation over the Sacramento area, which is providing showers
with embedded thunder and high-elevation snow this afternoon.
Early morning snow levels hovered near 7,500-8,000 feet, but are
expected to steadily climb during the day. As for the current
showers at the time of this writing, the majority are over
Mineral, Churchill and Pershing counties. Some showers are
appearing near far southern Mono County and far northern Washoe
County as the showers pivot around the broad circulation.

The heavier showers are expected to continue over the Basin and
Range early this afternoon, with convective showers expected to
filter in later today over the Sierra and leeside valleys. For
Sierra passes such as Ebbetts/Sonora/Tioga tonight into Tuesday
morning, there is a 60-90% chance to accumulate at least an inch
of snow above 7,500-8,000 feet. The greatest snow amounts are
expected on the ridges west of June Lake and just south of Tioga
Pass, where 4-8 inches of snow is not out of the question. After a
wet and cool evening and overnight, we will begin to see the
system exit eastward early Tuesday, only to be followed by yet
another system.

The next system will originate from near the Aleutian Islands as an
open wave and is expected to form a closed circulation off the coast
of Oregon. A hint of subtropical warmth and moisture appears to
influence this system as it arrives to our area. This storm has
appeared to slow in recent ensemble guidance, and along with the
influence from the subtropical intrusion, will be a slight bit
wetter than our current system. The focal point for the most
precipitation will be south of US-50 this time, so if your area
misses out on precipitation with the first system, you may be in
luck with this next round. Showers and isolated thunderstorms
begin Wednesday with emphasis near the Hwy 50 corridor, then
shifts slowly south into Mono-Mineral counties Thursday. This
time around we will be looking for Sierra snow to impact areas
mainly above 9,000 feet. This may again impact Ebbetts, Sonora and
Tioga passes. Some beneficial moisture is defintely in the cards
along the eastern Sierra with the official forecast showing a
solid 0.25-0.50" with a 40-60% chance of exceeding 0.50". We have
cooled Thursday`s highs 50% toward the NBM 10th-percentile to
account for the extensive clouds and precipitation.

This system will exit by early Friday AM, with some lingering light
showers over the Basin and Range. We will also see a return of
seasonal average temperatures and clearing skies, especially for the
weekend. Longer range outlooks suggest the warming and drying trend
are here to stay into the end of September. HRICH

&&

.AVIATION...

* Showers with embedded lightning and thunder are over the western
  Nevada Basin and Range early this afternoon, with more showers
  filling in across the Sierra and western NV as convection
  increases through this evening. Near active showers and storms,
  terrain obscurement and MVFR conditions are expected. Winds will
  be westerly with gusts to 25 kts possible over KRNO/KNFL/KCXP
  through this evening. Chance of a storm at any of the terminals
  is around 10-20%.

* Snow showers are anticipated to impact Sierra ridges tonight,
  bringing some icing concerns to the region overnight into early
  Tuesday morning. While there should be little to no
  accumulation of snow at KMMH, snow may mix into rain showers in
  the vicinity, above 9,000 feet.

* Westerly winds will increase tonight into Tuesday, with ridge
  gusts of 30-40 kts possible. Showers will exit Tuesday, with
  another system arriving Wednesday-Thursday. Probabilities are
  increasing (greater than 70% chance) for widespread MVFR
  conditions along the eastern Sierra (Tahoe/Reno southward to
  Mammoth Lakes) as latest scenarios indicated widespread
  showers/isolated thunderstorms. HRICH

&&

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

$$