Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 10/31/22

Area Forecast Discussion

National Weather Service Reno NV

 203 PM PDT Sun Oct 30 2022


.SYNOPSIS...

Mild afternoons, typically cold nights and dry conditions will
prevail through Monday. A cold winter storm arrives Tuesday through
Thursday with periods of rain, snow and wind along with much colder
temperatures.

&&

.DISCUSSION...

Enjoy these last couple of pleasant fall days across the Sierra and
western Nevada because a winter storm is still on track to impact
the region this week. A period of strong gusty winds, rain and snow
along with colder temperatures will inundate the area Tuesday
through Thursday. Let`s break it down by weather parameter.

* GUSTY WINDS (medium confidence): West-southwest winds will
  increase early Tuesday as the cold front approaches the northern
  Sierra and northwestern Nevada. Ridge and foothill winds will ramp
  up first before mixing down to all valley floors by mid morning to
  late afternoon. The upper level jet along with 40-50kt 700mb level
  winds will coincide with tightening surface gradients Tuesday
  afternoon to produce wind gusts 35-45 mph, with locally higher
  gusts to 55 mph for the typical windprone locations. Impacts
  include: travel concerns for high profile vehicles, turbulence and
  LLWS issues for aircraft and choppy conditions for recreational
  activities. Blowing dust is possible downwind of dry lake beds
  with localized fire weather concerns Tue afternoon/early evening
  where fuels remain receptive (mainly south of Hwy 50).

* COLD TEMPERATURES (high confidence): Plan on temperatures
  significantly dropping from the start of the week into the end of
  the week. The cold front sweeps over the I-80/Hwy 50 corridor
  around Tuesday afternoon and quickly shifts southeast overnight
  into early Wednesday morning. With temperatures in the 60s for
  many areas early this week, the highs 15-20 degrees below normal
  will be a bit of a shock! We`re looking at 30s in the Sierra
  valleys and 40s in the lower valleys Wed-Thu. Hard freezes likely,
  especially Wednesday/Thursday nights as skies clear and
  precipitation exits.

* QPF (low-medium confidence): QPF amounts are still about the same,
  although that may shift as the storm nears. From Tuesday into
  Tuesday night along the crest we`re looking at 0.75-0.90", with
  around 0.50" in the Tahoe Basin and northeast California/far
  northwest Nevada, 0.15-0.25" along the US-395 corridor, and up to
  0.15" in the Basin and Range. For Wednesday-Wednesday night,the
  low quick shifts eastward with amounts around 0.20" in the Sierra
  and less than 0.10" elsewhere. There is still model uncertainty
  here, so confidence is lower.

* SNOWFALL: Higher snow levels and warmer antecedent temperatures
  will limit snow accumulation initially with the storm`s arrival.
  Snow character will be quite wet and slushy as well Tuesday
  into early Tuesday night. Snowfall amounts with the first part
  of the storm will range 4-8" (locally up to 1 foot) for the
  Sierra above 7000 feet with moderate snowfall rates of 1-2"/hr
  over about a 4-6 hour period. For areas below 7000 feet as well
  as areas across northeast CA/far northwest NV, snow totals will
  be less due to much of the precipitation occurring during the
  day and the warmer conditions at onset. For the Tahoe Basin up
  to 3" of heavy wet snow is possible while for western NV there
  will be light accumulations for areas above 5000 feet through
  Tuesday night. As the colder part of the storm, Wednesday into
  Thursday, plan on snow and pellet showers for much of the
  region. Snow character will be lighter and drier with higher
  snow ratios in the cold air. Don`t be surprised by light
  accumulations across the Sierra and western Nevada Wednesday or
  Thursday mornings. Plan on slick roads and potential slow downs,
  definitely for the Sierra routes and possibly for the lower
  valley areas.

By next weekend, the outlook is dry with a return to mild daytime
highs and typically cold nights/mornings.

-Edan

&&

.AVIATION...

* Dry and mild with VFR conditions and light winds through Monday
  afternoon. No aviation concerns. Starting Tuesday there will be
  more aviation impacts as an early winter storm drops into the
  Sierra and western Nevada.

* Monday PM - Tuesday: A period of gusty winds, turbulence and LLWS
  is likely ahead of the cold front passage. West to southwest
  surface wind gusts 25 to 35 kts with 45 to 60 kts at FL100 as the
  front passes through Tuesday afternoon. Winds will shift out of
  the north to northwest Tuesday night into Wednesday.

* Tuesday Afternoon - Wednesday Morning: Weather impacts will shift
  to rain and snow as the front drops through the northern Sierra
  and spread southward across western Nevada. An inch or two of snow
  accumulation remains possible for the Sierra terminals from
  Tuesday into Thursday with some light accumulation potential for
  lower elevation airports Tuesday overnight into Wednesday night.

* Thursday: Breezy northerly surface winds will persist with
  stronger northeasterly winds at FL100. LLWS and turbulence
  concerns may return, especially along and west of the Sierra, with
  lighter surface winds and stronger winds aloft.

-Edan

&&


.REV Watches/Warnings/Advisories...
NV...Winter Storm Watch from late Monday night through Wednesday
     afternoon NVZ002.

CA...Winter Storm Watch from late Monday night through Wednesday
     afternoon CAZ071>073.

&&

$$