146
FXUS65 KREV 232213
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
213 PM PST Tue Dec 23 2025

.KEY MESSAGES...

* Mostly dry weather continues into the evening with gusty winds
  lingering overnight.

* Periods of heavy Sierra snow, lower elevation rain and snow, and
  strong, gusty winds expected tonight through Friday.

* Drier weather returns this weekend and continues into next week,
  accompanied by chilly temperatures.

&&

.DISCUSSION...

A mostly dry, albeit windy, day is providing a brief window for pre-
Christmas travel in and across the Sierra before our next winter
storm arrives tonight. Winds will be the main near term concern as a
belt of 40-50 kt 700 mb flow and ample mixing support S/SW gusts of
35-45 mph across lower valleys and 80-100 mph along Sierra ridges. A
more concentrated wind concern likely materializes late this
afternoon through Wednesday morning across S.Lyon, Mineral,
Churchill, and Pershing Co. where southerly gusts increase to 45-55
mph in response to a deepening surface low to our west. Wind prone
areas such as US-95 near Walker Lake may even see gusts up to 60
mph. These winds may serve as crosswind driving hazards for those
traveling along E-W oriented portions of US-95 and US-50.

The first in a pair of winter storms will begin to impact the region
late tonight through most of Christmas Eve. A band of rain and snow
overspreads northeast California and the Sierra after 10 PM PST
tonight with rain spilling into western Nevada early Wednesday
morning. Snow levels begin around 7500-8000` at the onset of
precipitation before falling between 6000` and 7000` by midday
Wednesday. Additional rainfall around the Tahoe Basin northward will
renew flooding concerns until rain switches to snow, especially for
urban and poor drainage areas. More details on flooding impacts can
be found in the Hydrology section below. Also, don`t be surprised to
hear a few rumbles of thunder near the Sierra crest on Wednesday!

While we won`t get an extended break in between storms, there does
appear to be a brief lull in shower activity Wednesday afternoon and
evening before the second winter storm arrives early Christmas Day.
Periods of heavy snow are slated to begin Christmas morning
across the Sierra and continue into Friday, producing significant
travel disruptions across mountain passes and at lake level. Lower
elevation roadways in Mono County (e.g., US-395) will also see
difficult travel conditions due to moderate to heavy snowfall. If
heavy snow wasn`t enough, strong winds and subsequent blowing snow
may drastically reduce visibilities on Christmas. Needless to
say, avoid traveling in and across the Sierra after today.

For W NV foothills and valleys, expect periods of moderate to heavy
rain until Christmas night when snow levels fall to around 5500`. As
such, concerns for snow impacts spread into foothill communities,
such as Virginia City, Christmas evening into Friday morning.
Snow levels fall near/below valley floors Friday morning, giving
the Greater Reno-Carson-Minden area a 20-40% chance of an inch of
snow on Friday. Uncertainty is high on how/when snow might reach W
Nevada valley areas, but it`s certainly something to keep in mind
as snow impacts to travel are on the table. Winds will remain
gusty each day through Friday, but Thursday is favored to be the
windiest day as many areas have a 60+% chance of seeing gusts of
45 mph or greater. So while daily wind impacts to travel and
recreation are likely through Friday, Thursday may offer more
significant wind impacts.

A drying trend begins after Friday as the Christmas storm finally
departs the region, leaving behind very chilly temperatures
regionwide over the weekend. Additional winter storms are possible
to ring in the new year, but details are to be determined.

-Salas

&&

.AVIATION...

* VFR conditions this afternoon will be accompanied by gusty surface
  winds at all terminals. LLWS remains a concern through the
  forecast period. Wind gusts of 45-50kts are expected to increase
  to near 55-60 kts this evening ahead of the incoming weather
  system.

* As early as 06-09z Wednesday we expect showers to arrive to
  Sierra terminals. By 12z, some showers will spillover into
  western Nevada valley terminals. Mountain obscurations, moderate
  turbulence and LLWS with gusty surface winds will all be present
  on Wednesday. Initial precipitation for Sierra terminals may
  start as rain or rain/snow mix Wednesday before changing over to
  all snow for Thursday. Snow will be possible for KRNO/KCXP/KMEV
  on Thursday, but amounts are expected to be light, with a 5-10%
  chance for an inch at KRNO and a 10-20% chance for an inch of
  snow at KCXP and KMEV. HRICH

&&

.HYDROLOGY...

Flooding concerns will be renewed late Tuesday through Wednesday
when the next storm brings additional rain before eventually
transitioning to snow. Areas of concern will be urban and poor
drainage areas, and creeks and streams from Lake Tahoe through
Lassen County. The greatest flooding concern is for rivers and
streams draining large watersheds below about 6,500`. This includes
many streams in Sierra, Plumas and Lassen counties and the Susan
River.

Minor flooding is possible, but not currently forecast, for the
Susan River on Christmas Eve. The runoff in the Susan and other
similar drainages will be very sensitive to the duration of rain
vs. snow, and any delay in the transition to snowfall could
easily push the Susan River higher. For example, a simulation with
just a 500` increase in the rain/snow line leads to a second
second peak on the Susan River approaching moderate flood stage
on Christmas Day. No other main-stem rivers are forecast to
flood, but slow rises and high flows are expected on the Pit
River below Canby, and Middle Fork of the Feather near Portola.

Enhanced runoff and sediment transport including rock fall are
possible within and below recent burn areas. Post-Fire debris flows
are not expected.

The River Forecast Center will be extending hours this week and
issuing additional forecasts for rivers where flooding is
expected. Check for updated river forecasts at: www.cnrfc.noaa.gov

-Bardsley

&&

.REV Watches/Warnings/Advisories...
NV...Winter Storm Warning from 10 PM this evening to 10 AM PST Friday
     NVZ002.

     Lake Wind Advisory until 10 PM PST this evening NVZ002.

     Wind Advisory until 7 AM PST Wednesday NVZ001-004.

CA...Flood Watch from 10 PM PST this evening through Wednesday
     evening CAZ071.

     Winter Storm Warning from 10 PM this evening to 10 AM PST Friday
     CAZ071>073.

     Lake Wind Advisory until 10 PM PST this evening CAZ072.

&&

$$