Area Forecast Discussion
Issued by NWS Reno, NV

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

000
FXUS65 KREV 202332
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
332 PM PST Tue Feb 20 2018

.SYNOPSIS...

A cold low pressure trough will remain over the region this week
with below normal temperatures. More snow is likely late Wednesday
night and Thursday as another disturbance moves through the region.
A break in snow chances is expected for the weekend, with a strong
cold front expected early next week.

&&

.SHORT TERM...

SUMMARY OF IMPACTS THROUGH THURSDAY:

* "Inside Slider" with morning commute snowfall possible in
  western Nevada for Thursday. Be prepared for a much longer
  commute Thursday. MODERATE CONFIDENCE.

* Timing of heaviest snowfall between 6 AM and 1 PM Thursday.

A weak, disjointed upper disturbance will move over northeast
California and western Nevada tonight and Wednesday. There is no
apparent deep focus for snow so the disturbance is mainly expected
to bring mid and/or high cloud cover. Still, a few flurries or
brief very light snow showers are possible although little or no
impact is expected.

Another, much more organized disturbance is expected late Wednesday
night into Thursday as a shortwave moves through the large scale
trough hanging over the Great Basin. That disturbance is expected
to take an "inside slider" path with the core of the system
dropping inside the Pacific Northwest coast and south along or
near the Sierra crest. While any precipitation is guaranteed to
be snow, snowfall amounts with inside sliders are notoriously very
sensitive to the exact track the system takes. If the track winds
up just east or along the crest, then the Sierra will generally
see less/much less snowfall than western and west-central Nevada.
However, if the track is over the lower foothills on the west
side of the Sierra, then the Sierra and northeast California often
see more snowfall than western Nevada as stronger orographic flow
comes into play.

Timing-wise, the heaviest snowfall Thursday in western Nevada is
expected somewhere between 6 AM and 1 PM. If this occurs on the
earlier side, then impacts to Thursday morning`s commute are
definitely on the table. If it occurs towards the later end of the
range, then road temperatures below about 8000 feet are likely to
be warm enough to melt any snowfall, especially outside of heavy,
persistent snow bands (unpredictable locations at this point).

With very cold temperatures aloft high liquid to snow ratios are
expected with Thursday`s slider, bringing a fluffy snowfall (bad
for snowballs!). At this time, snow amounts around 2-5 inches are
possible for NE California and the Tahoe basin, with 1-4 inches
for Mammoth Lakes. Higher amounts to 5-8 inches are possible in
the higher elevations of the northern Sierra; however, high Sierra
snowfall will be dependent on if the slider`s track is west of
the crest (more snow) or not (much less snowfall). In western
Nevada, we could see up to 2 inches of snow, with 2-4 inches in
the foothills. -Snyder

.LONG TERM...Saturday through Tuesday...

An active pattern of cold shortwave troughs will continue into next
week. Although theses are not big moisture-laden storms, they will
provide reinforcing rounds of cold air and snow showers with snow
levels remaining near or below all valley floors.

Unsettled weather looks to begin as early as Sunday night as the
first shortwave approaches the Pacific Northwest. The character and
progression of this system looks to be of a brief period of
moderate/heavy banded snowfall along the cold front in the Sunday
night to Monday morning timeframe, followed by instability driven
scattered snow showers behind the front possibly through Tuesday.

These type of shortwave troughs (sliders) typically become more
clear around 2-3 days ahead of time so specifics on timing and
snowfall amounts won`t begin to come into focus until the start of
this weekend. In the meantime, if you have any travel plans over the
weekend, the timeframe through Sunday afternoon looks good so far,
but the chances for winter driving conditions increases Sunday
evening into early next week. Be sure to keep up with the latest
forecasts updates. Fuentes

&&

.AVIATION...

VFR conditions (just higher clouds) are expected through Wednesday.
A few flurries will be possible late tonight and Wednesday; however,
no accumulations are expected. -Snyder

&&

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

$$

For more information from the National Weather Service visit...
http://weather.gov/reno


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.