Area Forecast Discussion
Issued by NWS Reno, NV
FXUS65 KREV 260939
Area Forecast Discussion
National Weather Service Reno NV
239 AM PDT MON SEP 26 2016
Strong high pressure will remain over northern California and
Nevada through Tuesday bringing dry conditions, light winds and
well above normal temperatures. Wednesday, high pressure begins
to weaken with an increase in cloud cover, especially south of
highway 50. Breezy and cooler conditions return area-wide for
late week as low pressure approaches the Pacific Northwest.
An upper ridge is centered over southeastern Oregon, with a
surface high centered over northeast NV and Utah. The combination
of the east-to-west surface gradient and easterly flow aloft
around the ridge is bringing another morning of moderate flow over
Sierra ridges with gusts 35-50 mph (highest at the immediate crest).
Valleys winds are mainly light, although buoy winds on Lake Tahoe
are currently easterly between 10 and 15 mph.
This afternoon and tonight, the ridge axis expands over northern
CA and NV and brings much lighter winds to the crest. The weakening
winds are expected to allow for better mixing today with highs
warming a few more degrees...into the mid to upper 80s in the
lower valleys and mid 70s to lower 80s in Sierra valleys. Tuesday,
the ridge axis remains overhead for well above average temperatures
in the mid 80s to near 90 in the lower valleys.
On Wednesday, an upper low moves from southern CA into southern NV.
The low will be weakening as it squeezes between the upper ridge
(centered over the Rockies by Wednesday) and an upper trough
approaching the Pacific Northwest. Despite the weakness of the
low, a modest deformation axis may combine with well above average
afternoon temperatures to bring some cumulus buildups to areas
south of highway 50. The NAM is the farthest west with the axis
and even develops some light QPF in Mono and western Mineral
Counties. Meanwhile, the GFS and EC keep precip confined to central
NV and Inyo County. For now, have continued the very low POP with
just an increase in clouds for areas south of I-80 with many model
runs keeping showers out of the area. -Snyder
.LONG TERM...Thursday through Sunday...
The models continue to advertise a cool trough for the weekend with
winds increasing ahead of it. Thursday will see the first day of
increased winds, but the models are just beginning to increase the
winds aloft. Friday still looks to be a breezy day for all locations,
but just how strong is still in question. The winds then are
expected to be less of a factor over the weekend behind the cold
As for precip, most of the moisture will remain to the north over
Oregon. However, I retained the slight chance of showers close to
the Oregon border each day Fri-Sun. The models do bring some light
precip to these areas with the better chance of showers Saturday
and Sunday. Snow levels will fall behind the front with these
showers, and may drop to 7000 feet or lower for Sunday. Temps will
still see a decent decrease during the period with slightly above
average values Thursday falling to about 10 degrees below normal
for the weekend. Wallmann
VFR conditions through Wednesday. Sierra ridge winds remain gusty
again this morning with peak gusts to 45 kts. Expect these to
decrease by 18Z with generally light winds thereafter. Wallmann
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