Area Forecast Discussion
Issued by NWS Elko, NV

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FXUS65 KLKN 221010

Area Forecast Discussion
National Weather Service Elko NV
310 AM PDT Fri Oct 22 2021

.SYNOPSIS...A first in a series of moist and windy Pacific waves
moves across northwestern and far northern Nevada today. Showers
will expand across northern Nevada region on Saturday with cooler
temperatures. A much stronger Pacific storm brings widespread rain
on Monday.


.SHORT TERM...Today through Saturday evening.
The first in a series of Pacific waves with deep moisture is
moving across northern California, projected to move into western
Nevada later this morning. With the long wave trough remaining
well offshore, the leading wave encounters the downstream ridge
and lifts northeast into Idaho. Showers are expected along the
front as it moves across Humboldt County, but becomes less
organized as it slides across northern Elko County. This fast
moving wave only generates light rainfall amounts with valley
spots receiving less than a tenth of an inch /0.10/. Windy
conditions are expected with gusts reaching 30-35 mph this

Upstream secondary wave will carve out a low amplitude trough
over the Great Basin by Saturday morning, re-energizing the
surface front over northeast Nevada. Showers will expand across
northern Nevada as far south as route US50. The trend will be for
diminishing showers Saturday as the secondary wave moves
downstream. The highest rainfall totals occurs along the front and
local spots in northeast Nevada could receive a quarter inch
/0.25/. Snow accumulations limited above the mountain passes,
although a rain/snow mix may occur above 7000 feet.

.LONG TERM...Saturday night through next Thursday.

Saturday evening through Tuesday, is shaping up to be a very wet
period across the whole of NV. This will come in the form of a
atmospheric river system and it supporting trough passing across
western CONUS. This will spread rain and snow across NV starting
in the northwest NV Saturday night. This precipitation then looks
to reach its zenith Monday early morning to early afternoon. The
precipitation then looks to dwindle downward through Tuesday and
largely end by Wednesday. The precipitation should be mainly rain
for the valleys as the system does not bring colder air across NV
until Tuesday morning when the event is starting to end. Any
snowfall that does occur will be in the highest mountains peaks
which may pick up significant snowfall. The overall amount of
moisture associated with this event has continued to increase from
previous model runs. The ensembles have continued to favor higher
moisture and precipitation amounts as the system comes closure to
occurrence. These have pegged this system as being in the 99%
99.5% percentile across NV during it zenith on Monday morning.
What this means in simple terms is this is shaping up to be an
extreme event that can produce historic amounts of precipitation
for the 25th of October. The current favored amounts of 0.5 to 1.0
inches of rain may not sound like much but these beat out the
current records which stand at 0.25 to 0.4 inches of rain. Given
that this rainfall is over a long period of time impacts are not
expected to by high as of now. Through not as dramatic as the
rainfall this system should produce gusty winds across northern
and central NV during its passage with gusts generally in the 20s
and 30s mph range. There could also be a few stronger gusts in the
40s mph in White Pine County as well with better chances at
higher elevation.

Wednesday through Friday, should see the system fully depart the
region with the pattern favoring a shift to a ridge. The overall
intensity of the ridge is hard to pin down but ensembles are
favoring a stronger overall ridge. This should produce a fairly
warm period across the silver state with fair weather and lighter


VFR conditions are expected through the next 24 hours, though
-SHRA possible after 20Z at KWMC may bring degraded CIGS to 2.5K
FT AGL. Strong winds are expected to develop across all TAF sites
this afternoon SW-W10-20G30-35KT.




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