High Wind in Nevada, September 11, 2024

Area Forecast Discussion
National Weather Service Reno NV
222 PM PDT Wed Sep 11 2024

.SYNOPSIS...

* Strong winds have created widespread critical fire weather
  conditions and will impact recreation and aviation activities
  today.

* Near to below normal temperatures expected for the remainder of
  this week with a chances for showers and storms along the Oregon
  border this afternoon.

* A low pressure system may provide another round of gusty winds,
  cooler weather, and potential for precipitation early next week.

&&

.DISCUSSION...

The low pressure and associated trough is bringing gusty winds that
will become westerly this afternoon. Gusts at the time of the
writing are nearing 70 mph on Slide Mountain, while gusts near
Washoe Lake are exceeding 50 mph. Winds of these magnitudes have
brought about a Particularly Dangerous Situation Red Flag Warning
for the northern Sierra Front today from 11 AM through 8 PM tonight.
For more information on this product, see our Fire Weather section
below. Remember to heed instructions and warnings from local
authorities and monitor evacuation watches and warnings at
www.perimetermap.com.

Dry lake beds and desert sinks have the potential to see lofted dust
due to gusty winds up to 40+ mph on the valley floors. Sierra ridges
could see gusts 75+ mph today. Additionally, showers and storms are
beginning to erupt along the Oregon border. Areas such as
Cedarville, CA in Modoc County may see wetting rains this afternoon
under wetter storms, chances range 40-70%. High temperatures today
will range 80s in the lower valleys, with 60s and 70s for the Sierra
valleys. Lows tonight will tumble as the front passes, bringing
upper 30 to mid 40s to leeside valleys and 30s to Sierra valleys.

On the backside of this trough, winds will shift east-northeasterly
by Thursday morning, with gusts only approaching 10-15 mph for lower
valleys. We also expect to see a slight increase in relative
humidity, but only for a day. The wind direction will signal the
passage of the front, and with that we will see temperatures a bit
lowered for Thursday. Lower valleys will struggle to reach mid to
upper 70s, while the Sierra communities top out at near 70. Smoke
and haze will linger over the Truckee Meadows as the Davis Fire and
it's behavior will determine those details.

Taking a look into early next week, another trough looks to take aim
along the Pacific Coastal waters of northern California and southern
Oregon. This placement and orientation suggest a taste of fall on
the way, with gusty winds, falling temperatures and increasing
opportunity for showers and possibly even some snow on the higher
peaks of the Tahoe Basin. HRICH

&&

.AVIATION...

* Strong gusty winds, turbulence and LLWS today, with widespread
  ridge gusts nearing 65 kts and lower valley terminal gusts of 30-
  40 kts.

* Smoke and haze from the Davis Fire is affecting visibility for
  KRNO today, although recent modeling of the smoke plume suggests
  it could affect KNFL later today and Thursday, and KCXP/KMEV
  Thursday evening, once winds have shifted out of the east-
  northeast.

* Lighter winds arrive Thursday, with gusts for lower valley
  terminals only around 10 kts. The lighter winds will lessen the
  turbulence and LLWS threats, but the lighter winds will also
  lessen the mixing out of smoke and haze. HRICH

&&

.FIRE WEATHER...

1) Red Flag Warning for NV-420 Northern Sierra Front will continue
to be designated as a Particularly Dangerous Situation...

* Strong west winds with peak gusts of 40 mph or stronger are
  expected from the valley floors to the mid-slopes with gusts up to
  75 mph on ridgetops through 8 PM tonight. As of 11 AM multiple
  sites were reporting wind gusts over 40 mph across western NV with
  a couple of sites 50+ mph. Widespread very dry conditions ranging
  from 1-9% across the Basin and Range to 9-18% for the Sierra Front
  and the Eastern Sierra. Humidity values are projected to trend
  upwards through the day, but latest simulations don't show a
  significant upward movement until after 5 PM. Winds will begin to
  taper for the lower valleys after 8 PM, but ridges will stay quite
  breezy through 11 PM.

2) Red Flag Warnings for Western Nevada Basin and Range, Mineral
County, and the Eastern Sierra...

* Widespread west to southwest wind gusts 30 to 40 mph with dry
  conditions are expected until 8 pm for all other areas across
  western Nevada, Mineral county and the Eastern Sierra. It is
  imperative to be aware of the critical fire conditions and avoid
  activities that could spark a fire!

3)Thursday Onward

Thursday into Friday winds will be much lighter and generally north
to northeasterly. Unfortunately the northerly flow will transport
near surface smoke from fires in Idaho and Oregon into western
Nevada on Thursday. Smoke will trek as far west as Lake Tahoe, Reno
and into Mineral and Alpine counties as well. Temperatures will
markedly cooler as well as high relative humidity values with
lessening fire weather concerns for the end of the week into the
weekend. -Edan

&&

.REV Watches/Warnings/Advisories...
NV...Red Flag Warning until 8 PM PDT this evening NVZ420-421-423-429.

     Lake Wind Advisory until 8 PM PDT this evening NVZ002-004.

CA...Red Flag Warning until 8 PM PDT this evening CAZ274.

     Lake Wind Advisory until 8 PM PDT this evening CAZ072.

&&