Area Forecast Discussion
Issued by NWS Reno, NV
FXUS65 KREV 171021
Area Forecast Discussion
National Weather Service Reno NV
321 AM PDT Fri Mar 17 2017
A weak storm system will bring a few showers and gusty winds this
weekend. Temperatures will remain above average through Monday
with Friday expected to be the warmest day. A change to a more
active weather pattern with cooler temperatures is becoming more
likely for next week, possibly continuing into the weekend.
A few changes were made this morning, mainly to reduce the chance
of showers this weekend and increase the ridge winds. Gusty ridge
winds continue this morning with gusts up to 60 mph. Some of these
winds will mix down today with peak gusts up to 30 mph possible in
the valleys. Otherwise, a warm day is expected with highs into the
60s and 70s with clouds increasing during the afternoon.
The two short waves expected this weekend look to be shearing
apart more this morning in the latest model suite. As a result,
the moisture appears to be more mid and high level with quite a
bit of cloud cover, but little in the way of rain reaching the
surface. The most likely areas for any showers would be in the
mountains north of Tahoe and near the Oregon border. A second area
east of Fallon is possible with weak frontogenesis there, but the
best chances would likely be into Eastern NV. Snow levels will
remain high at 8-9000 feet, but surface temperatures will cool
some this weekend.
The other concern will be the winds, particularly Saturday where
700 mb winds increase to 30-40 kts. Good mixing on Saturday will
likely lead to surface wind gusts to 40 mph while the ridges gusts
near 80 mph. Lake will likely be choppy with some mtn wave
turbulence as well. Wallmann
.LONG TERM...Monday and beyond...
Spring may have sprung, but winter is not over yet. An active
weather pattern is expected to set back up for the Sierra next week.
The first storm of the week is a negatively tilted trough off the
coast of the Pacific northwest that is forecast to push two waves
into the Sierra. The first wave has slowed down a bit in recent
model runs with the bulk of the precipitation now expected early on
Tuesday. With the low a little farther offshore and southerly flow
ahead of the first wave, warmer air will be allowed in. This would
keep snow levels higher initially (falling below pass levels Tuesday
afternoon) and allow better mixing with stronger winds for western
Nevada on Tuesday.
The second weaker wave is expected on Wednesday. This will bring a
period of convective snow showers to the region. You know the ones,
sunny one minute, heavy snow the next. With colder air in place this
could be more disruptive to travel as snow levels are expected be in
the 5000-5500 foot range. Overall, between the 2 waves, still
expecting 1-1.5" QPF along the Sierra crest. However, with a cold
convective environment Tuesday night into Wednesday snow
accumulations could be enhanced from convective cells and
over perform forecast amounts in some places.
A short break is expected Wednesday night into Thursday, before
another potentially stronger storm could impact the region at the end
of the week. This storm has a better moisture tap with atmospheric
river tools showing increasing probabilities for a longer duration
event in northern and central California. It`s still too far out to
gauge overall precipitation amounts since slight changes in the
storm path can significantly effect the amount of precipitation that
makes it into the lee of the Sierra. What can be said though, there
continues to be increasing chances for wet and cooler weather
impacting the region through next weekend. -Zach
Gusty winds to 25 kts at terminals near the Sierra this afternoon
with some light mtn wave turbulence as ridge gust to 50 kts. The
turbulence will likely increase for Saturday as ridge winds
increase and gusts to 35 kts are possible for the valley
terminals. A short period of LLWS is possible 12-18Z Saturday
before the winds mix out. The exception will be near KTVL where
LLWS could continue all day due to terrain channeling.
Generally VFR conditions otherwise through 18Z Saturday with local
MVFR conds near Tahoe and west of KSVE afterward in -SHRA with
some mtn obscn. Wallmann
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