FXUS65 KREV 032213
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
213 PM PST Tue Dec 3 2024

.SYNOPSIS...

* Strong valley inversions persist at least into the start of the
  weekend with areas of freezing fog redeveloping each night.

* Expect near seasonable temperatures outside of valley areas
  impacted by fog and low clouds. 

* No significant storms are on the horizon through mid-month but a
  slider system could help erode the inversions by late weekend.

&&

.DISCUSSION...

Strong valley inversions with areas of freezing fog are expected
to persist at least into the start of the weekend as light winds 
and high pressure remain stagnant across the region. Areas most 
impacted by freezing fog continue to be from the Honey Lake basin 
into Pyramid Lake and adjacent desert basins. Fog may impact 
portions of I-80 across W.Nevada, especially near Fernley. Valley
areas outside of the freezing fog can still expect strong 
inversions with hazy conditions and reductions to air quality. 

Temperatures will remain near to a few degrees above early
December averages with highs in the upper 40s to low 50s across
western Nevada and the Sierra. The exception to this will be the
fogged in valleys which will struggle to reach the 40 degree mark.
The inversions will set up cold overnight lows in the valleys in
the teens and low 20s while warmer thermal belt areas along the
mid-slopes and ridgelines only drop to near the freezing mark. 

The first indications of at least some enhanced mixing and
ventilation to help scour out the lower valleys is targeting the
late Saturday to Sunday timeframe where a majority of ensemble
cluster scenarios develop an inland trajectory shortwave trough
passage "slider". The main uncertainty is with how far south the 
wave digs, but overall it appears to be our best potential of 
developing enough of a northwest flow to erode the inversions. 
There is not much moisture associated with this shortwave, which 
is typical with an inland trajectory, with only a 10-15% of light 
showers near the southern Oregon border on Sunday. Fuentes 

&&

.AVIATION...

* Expect strong valley inversions to persist at last into the
  weekend with areas of haze and minor reductions to slantwise 
  visibility for area terminals during the afternoon hours. 

* Areas of freezing fog and low stratus are expected to continue 
  across the Honey Lake Basin, Pyramid Lake area, stretching north
  through the Black Rock/Smoke Creek Deserts, and south to 
  Fernley. 

* Anticipate FZFG KSVE and KTRK from 09-17z with a 30% chance at
  KRNO and KRTS. Fuentes 

&&

.REV Watches/Warnings/Advisories...
NV...Freezing Fog Advisory from 8 PM this evening to 11 AM PST 
     Wednesday NVZ003>005.

CA...Freezing Fog Advisory from 8 PM this evening to 11 AM PST 
     Wednesday CAZ071.

&&

$$