611
FXUS65 KREV 281117
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
317 AM PST Fri Feb 28 2025

.SYNOPSIS...

* Unseasonably warm and dry through Saturday.

* Quick hitting storms bring Sierra snow, western Nevada rain or
  snow showers, and gusty winds Sunday and Monday, then again
  the middle of next week.

* Above normal precipitation and cooler than normal temperatures
  favored into mid-March.

&&

.DISCUSSION...

High pressure which settled over the Great Basin will continue to
at least bring dry and unseasonably warmer conditions to the
region today through Saturday. Enjoy this taste of Spring while it
lasts since changes will literally be in the wind starting
Sunday. Until then enjoy the mild daytime highs mostly in the 60s
for western NV valleys, and 50s across many Sierra locations. Some
western Nevada communities across the Basin and Range will enjoy
those very spring-like 70s on Saturday. Although it will be
mostly sunny, higher elevation locations around Mammoth Mountain
in Mono County will see highs staying in the low to mid 50s.

As the upper ridge continues to weaken overnight Saturday, a
colder winter weather system advances into the west coast. This
will open a period of active weather across the region Sunday
through Monday that continues into next week. Blended simulations
show temperatures taking a dive Sunday into early next week as a
cold front presses into NE-CA late Saturday night, then across
the Sierra into and western NV Sunday through Monday. This storm
will make temperatures feel more February-like going into March.

* Blended guidance shows a comparatively modest amount of Pacific
  moisture feeding into this system with light to moderate snow
  showers advancing across the Sierra Sunday morning then into
  western NV Sunday afternoon. Blended guidance is also showing
  winds staying mostly breezy from the west-southwest across the
  Sierra, and western NV with gusts staying 25-30 mph Sunday and
  Sunday evening, then decreasing overnight.

* But forcing from a 110kt Jet to the south, and colder
  temperatures enhancing local lapse rates will be enough to bring
  a 40-60% chance for at least 3-5 inches of accumulated snowfall
  and travel impacts across higher mountain passes Sunday into
  early Monday morning. If subsequent model simulations show any
  higher amounts of moisture, winter weather advisories may be
  necessary.

* Snow levels are now projected to drop to 4000-5500` throughout
  this colder incoming storm system with the increased chance for
  some snow reaching down into foothill areas by Sunday with a
  dusting of snow for some Basin and Range areas from US-95 east
  into west-central NV overnight Sunday night.

No sooner than precipitation from this storm system presses eastward
later Monday into Tuesday morning, multi-model ensemble precipitation
simulations show a colder winter storm system bringing another
round of accumulated snow to the Sierra by the middle of the
upcoming week. Based on current simulations indicating a more
southerly storm track favoring areas south of highway 50, there is
a low confidence projection of some spillover of light snow into
higher foothill areas east of the Sierra Front and eastern Sierra
Crest. Simulations still point towards snow levels hovering around
5000 feet and staying off western NV valley floors. Therefore,
look for light rain showers tracking across western NV. These
showers will at least add a few hundredths to a third of an inch
of liquid precipitation to those areas. Blended guidance also
shows winds starting breezy from the southwest gusting 15-25 mph
that shift more north-northwest with passage of the cold front
across western NV.

-Amanda

&&

.AVIATION...

Low pressure centered offshore the CNTRL/SRN CA coast will push high
level cloudiness over the eastern Sierra, the Lake Tahoe Basin, then
north into NE-CA through today. This will do little to alter the
widespread VFR conditions across the region. Winds will be mostly
light less that 10 kts with main terminals seeing easterly flow this
afternoon. FL100 winds aloft, however, will experience an uptick in
speeds to 15-25 kts after 18Z, especially areas south-southeast from
Lake Tahoe Basin to the eastern Sierra-Mono-Mineral counties.
That said, KMMH will see southeast winds gusting to 20 kts this
morning into the afternoon. A cold, quick-hitting winter storm is
still on tap by early Sunday morning, bringing gusty winds,
mountain snow, and valley rain for Sierra and western NV
terminals.

-Amanda

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$