299
FXUS65 KREV 142031
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
131 PM PDT Sat Sep 14 2024

.SYNOPSIS...

* Gusty SW winds Sunday, with choppy lakes and localized critical
  fire weather conditions.

* Significantly colder Monday with increasing chances for rain and
  high elevation snow, along with isolated thunderstorms.

* Another cold storm arrives late Tuesday into Wednesday with more
  chances for rain and high elevation snow.

&&

.DISCUSSION...

* Hope you were able to get outside and take advantage of this (IMO)
  beautiful mid-September day! We`ll see southwest winds increasing
  once again Sunday ahead of a cold front, but the strength and
  duration do not look quite as intense as what the region
  experienced this past Wednesday. Still, it will bring choppy lake
  conditions in addition to localized critical fire weather
  concerns. See the fire weather section below for additional
  details.

* The associated upper level trough shifts into the region Sunday
  night into Monday, ushering in a significantly colder air mass
  and increasing rain and high level snow chances. There remains a
  rather significant spread in where the heaviest bands of
  precipitation will occur, but the HREF is in the best agreement
  in west-central Nevada. One stand out is the HRRR developing
  convectively banded heavier precipitation before daybreak Monday
  from the Tahoe Basin into NE CA. It is an outlier, but also
  would be more impactful with snow levels possibly dipping to
  near 6000` in the band and greater concerns for heavier rainfall
  over recent burn scars (Bear and Davis). Per NBM probs, the
  entire region has 60-70% chances to see wetting rains (0.10"+)
  Monday. Temperatures will be ~20-25 degrees below normal Monday,
  more similar to late October norms. The combination of
  rain/snow, cold temps, and breezy NW winds will be quite the
  shock to those who aren`t prepared, esp if recreating in the
  backcountry. There are also thunderstorm chances (10-20%) under
  the core of the low, in particular south of US-50 and areas
  near and east of US-95.

* While some showers may linger in north-central Nevada into
  Tuesday morning, the low quickly kicks east Tuesday with a bit
  of warming and drier conditions. This is short-lived as the next
  low pressure system follows right behind Tuesday night into
  Wednesday. Interestingly, there is actually better agreement in
  the placement of this cold low and associated precipitation
  Wednesday than what ensembles are indicating on Monday. In any
  event, this brings the return of colder temps, rain and high
  elevation snow, and isolated thunderstorms as well.

* A gradual warming and drying trend will be on track as we head
  into late week and next weekend with no major wind or rain
  events on the horizon. -Dawn

&&

.AVIATION...

* Flying conditions will be favorable the remainder of today with
  mostly clear skies and typical afternoon breezes through 03z.

* Winds will ramp up Sunday with SW FL100 winds sustained 30-40 kts,
  leading to mountain wave turbulence along and downwind of the
  Sierra. Terminals will see gusts of 25-30 kts from 19z-03z.

* Breezy NW winds to follow Monday behind a cold front, with
  widespread rain and high elevation snow. While conditions
  generally will remain VFR, localized IFR is certainly possibly
  along with mountain top obscuration in the heavier showers. There
  is also a 10-20% chance for thunderstorms, primarily south of US-
  50 and near/east of US-95.

* While chances are only about 20% for snow at KTRK, KTVL, and
  KMMH, if snow does fall, the warmer ground and mid-September sun
  angle should help snow to rapidly melt on runways. -Dawn

&&

.FIRE WEATHER...

* Winds ramp up out of the southwest Sunday ahead of a cold front
  slated to shift through the area Sunday night. While speeds do
  not look as intense or widespread as the event that unfolded
  this past Wednesday, it still bears watching with solid chances
  for 30-40 mph gusts late morning through late afternoon,
  especially along the Sierra Front, including the US-395/I-580
  corridor. Sierra ridge gusts will be in the 60-80 mph range
  ahead of the front.

* RH values are much higher than the last event as well, generally
  25-40% in valley locations. Localized critical conditions are
  expected, but no watches or warnings are planned at this time.

* Breezy NW winds with gusts of 20-25 mph to follow on Monday.

* Widespread wetting rains (0.10"+) are likely (60-70% chance)
  Monday and again Wednesday as a pair of cold weather systems drop
  into the region. These storms are cold enough to bring up to a few
  inches of snow to high elevation terrain. -Dawn

&&

.REV Watches/Warnings/Advisories...
NV...Lake Wind Advisory from 11 AM to 8 PM PDT Sunday NVZ002.

CA...Lake Wind Advisory from 11 AM to 8 PM PDT Sunday CAZ072.

&&

$$