Heavy Snow in Nevada, March 5 to 6, 2025

Area Forecast Discussion
National Weather Service Las Vegas NV
925 AM PST Wed Mar 5 2025

.SYNOPSIS...Expect cloud cover and precipitation spreading west-to-
east across the forecast area today with widespread rain and
mountain snow. Accompanying it will be gusty southwest winds and a
drop in temperatures. Conditions clear up through the weekend before
another round of unsettled weather returns.

&&

.UPDATE...As evidenced by the widespread cloud cover, moisture
continues to stream into the area ahead of our next system. Light
radar returns and some sprinkles have been noted across western San
Bernardino and eastern Kern counties. Bumped up PoPs from this
region to the Spring Mountains to account for this. SNOTEL sites in
the eastern Sierra have shown RH increases to around 90% with a few
sites noting snow depth increases of ~1". As moisture advection
persists and forcing from the trough approaches later today, we'll
see precipitation spread into the southern Great Basin and then
translate eastward tonight. Best chances (~75%) for rain in Las
Vegas between 10pm and 4am, but we'll be fighting some serious rain
shadowing so anything that falls will be light. Precipitation
chances on Thursday are expected to be less widespread, with the
main focus area being along the cold front northwest of Las Vegas.
Rain/snow shower activity becomes more isolated on Friday as the
second part of this system slides to our south. Dry conditions
return this weekend but another system takes aim early next week.

&&

.SHORT TERM...Today through Friday.

A bimodal trough will push through the region today, bringing 2
rounds of precipitation along with it. However, 2 notable trends
were observed on yesterday's afternoon shift that continue into this
morning's shift... 1. Snow levels with the first round of
precipitation continue to trend higher / warmer. 2. The trajectory
of the second wave continues to sag further south. These two
trends will result in a decrease of mountain snowfall amounts and
valley rainfall amounts, respectively.

We're starting to see light radar returns on the eastern Sierra
Slopes this morning. Returns will continue to enhance through the
morning, with the Winter Storm Warning for the eastern Sierra Slopes
starting at 4am. Despite inhibited precipitation in the southwestern
Great Basin due to rain shadowing from the Sierra, enough moisture
should spill over to result in 2-6 inches in the White Mountains
above 5000 feet. For this reason, the Winter Weather Advisory for
that zone will begin at 4am as well. Moisture will continue to push
eastward through the forecast area as the day progresses. Several
runs of the HRRR have indicated that this moisture will congeal
into a band of precipitation that will extend from Morongo Valley
through Barstow-Daggett into Death Valley, Beatty, and Lincoln
County between 12pm and 2pm this afternoon. This band will then
swing eastward through the remainder of the forecast area through
the evening, lining up along Mohave County and eastern Lincoln
County between 1 and 3am. The Winter Weather Advisory for
Esmeralda and central Nye above 5000 feet goes into effect at 4pm
this afternoon, as does the Winter Storm Warning for Lincoln
County above 5000 feet and the Spring Mountains above 5000 feet.
With that in mind, snow levels with the afternoon band will range
from 6500 to 7500 feet. As mentioned, this increase in snow levels
has resulted in a decrease in forecast snow amounts in the lower
elevations of the Spring Mountains such as Kyle Canyon. That said,
as the cold front pushes through the region early Thursday, snow
levels drop to 4500-5500 feet, which will allow for increased
snowfall accumulations in these locations, as the cold pool aloft
and enhanced dynamics result in heavier precipitation rates than
this afternoon.

The second wave will move through the region late Thursday into
Friday afternoon. Due to the limited moisture associated with the
second wave coupled with its further south trajectory, expect
scattered shower activity across the forecast area, rather than a
strong band of precipitation. Locally greater precipitation
amounts will be seen in the higher terrain, but desert locations
could see between 0.01 and 0.05" of additional rainfall with this
second round.

In addition to widespread precipitation, the region will see a stark
temperature drop of 8-12 degrees between this afternoon and Thursday
afternoon. As is typical with high temperature gradients, expect
strong gusty southwest winds today and Thursday across the Mojave
Desert. The strongest winds will be in northern and western San
Bernardino County, where gusts will range from 45 to 55 mph in
Morongo Valley, Barstow-Daggett, and around Mountain Pass at
Interstate 15. Wind Advisories for these zones begin at 7pm this
evening and continue through 1am Friday. Localized gusts to 40 mph
are possible in western and southern Las Vegas on Thursday with
isolated instances of downsloping, but these speeds are not expected
to be widespread enough or long enough duration to warrant a wind
headline at this time. Also took a look at the Owens Valley -
specifically downslope potential south of Lone Pine - where there is
a 30-40% chance of gusts exceeding 40 mph across Highway 395; held
off on issuing there as well. Will continue to assess the need for
wind headlines in these zones for Thursday and will consider how
today's winds pan out on the next couple of shifts.

.LONG TERM...Saturday through Wednesday.

A large, but fairly progressive ridge will build back into the
region over the weekend, allowing for temperatures to return
close to seasonal normals along with mostly sunny skies. High
pressure building over the Great Basin may keep some lingering
north winds going down the Colorado River on Saturday, but
generally light winds are expected across the region. After a
short break, yet another Pacific trough will make its approach to
the region by Monday. Still a bit early to speculate on the
details with this next system, as there remains considerable
variability with regard to its depth and timing. But at the very
least, a return of gusty winds and mountain precipitation chances
expected next week with temperatures trending downward by
midweek.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...This
morning,  winds will remain light and variable before settling
out of the east-northeast just after 19Z. By around 22-00Z, winds
shift to the southwest and increase to 12-15KT with gusts to
20-25KT. Of additional concern are rain showers that will impact
the terminal. Initially, coverage will be sparse, beginning near
06/00Z, with the best window for a band of rain to move through
the area between 05-11Z. There is uncertainty regarding the
precise timing of showers as well as potential impacts such as
brief periods of reduced visibility. For now, have maintained
unrestricted visibility, though ceilings around 6-7kft are
expected late this afternoon through Thursday morning. Of note,
however, is there is a 25% probability for a brief period of
ceilings around 3kft late tonight. As the band of showers moves
out in the morning, ceilings will lift and scatter, with
elevated/gusty southwesterly winds continuing through the end of
the forecast period.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...An approaching system
will bring increasing clouds and precipitation chances today and
tonight. Light winds at KBIH this morning shift to the southeast
and become gusty after 18Z, with rain showers expected to impact
the terminal from late morning through mid afternoon, with
ceilings around 1.5-3kft. After 00Z, conditions at KBIH will
improve as winds shift to the north- northwest. KDAG will also
have light winds this morning and afternoon that will shift to the
west-southwest and become gusty with gusts to 25-30KT after 23Z.
Rain showers will also impact the terminal, especially this
afternoon through tonight, shifting east after 08Z. Further east,
Las Vegas Valley terminals will follow similar trends as KLAS,
with KVGT and KHND seeing light and variable/diurnal winds through
early afternoon before winds shift to the southwest and become
gusty. Showers will develop in the vicinity this afternoon, with
the best window for precipitation from roughly 05-11Z, tapering
off thereafter. Lower Colorado River Valley terminals will be the
last to see precipitation from this system, with rain showers
there expected to hold off until after 04-06Z, with the best
chance for rain at the end of the forecast period. KEED and KIFP
will both have variable winds this morning, shifting to the south
by around 18Z and becoming gusty, with gusts to 20- 25KT. These
gusty winds will then continue, with ceilings dropping to around
8kft this evening and tonight.

&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

UPDATE...Woods
SHORT TERM...Soulat
LONG TERM...Outler
AVIATION...Phillipson

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