Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 270410 AAA
AFDREV

Area Forecast Discussion...UPDATED
National Weather Service Reno NV
910 PM PDT Wed Apr 26 2017

.UPDATE...

All wind-related advisories have been allowed to expire as winds
have diminished below criteria. The strongest gusts and sustained
speeds from this afternoon-early evening in the advisory area
occurred in west central NV west of Lovelock airport, and along
US-95 in Mineral County, with peak gusts around 50 mph and peak
sustained winds 30-40 mph. Just outside the advisory area, portions
of Douglas County and wind prone sites around Washoe Valley and
northwest of Spanish Springs received gusts near 60 mph for a
short duration. Ridge top wind gusts peaked near 100 mph earlier
today.

As of 9 pm, shower activity has decreased but not completely
ended. Some cells have recently developed in north central CA
between Chico and Red Bluff, which could hang on long enough or
trigger new cell formation from western Lassen County to the Tahoe
basin through the rest of this evening. Farther east, lighter
showers continue to move across parts of northwest and west
central NV. Latest guidance and the current forecast indicate
this shower activity winding down by midnight, except near the
Lander County line where a few brief showers could last into the
pre-dawn hours. MJD

&&

.PREVIOUS DISCUSSION... /Issued 138 PM PDT Wed Apr 26 2017/

SYNOPSIS...
Windy conditions with light Sierra showers will continue into
tonight as low pressure moves through northern Nevada.
Temperatures will remain on the cool side through the end of the
week. High pressure returns for the weekend with warm and dry
weather.

SHORT TERM...

So far today gusty winds have remained in the usual wind prone
locations along US-395/I-580 with peak gusts of 40-50 mph. High
resolution models are focusing the strongest winds this
afternoon/evening from Pyramid Lake/Reno area through Lyon,
Churchill and Mineral Counties. This will primarily impact those
on I-80 from Reno to US 95, US-50 from Carson to Fallon, and
US-95 from I-80 to Tonopah. Winds should start to weaken around
8pm or so, though gusty north to northwest winds will continue
overnight and into tomorrow. Only wind impact for Thursday would
be on Pyramid Lake where the northwest winds are aligned with the
long lake axis which may help increase speeds and kick up some 3
foot waves. Those heading out to fish or boat on Pyramid should
be cautious of choppy or even rough lake conditions.

Light showers along the Sierra Crest from Plumas-Eureka State Park
to Tioga Pass will continue into tonight due to moist upslope
flow. Snow levels are above 8000 feet, so not expecting any major
travel impacts. A second round warm air advection showers over
southern Oregon and northern California will pass across the
region from late afternoon and tonight, but with only light
rainfall amounts.

High pressure to build into the west on Friday with an area of
low pressure developing over the 4-Corners region. This will
reinforce the chilly north to northeast surface flow and keep
afternoon highs in the 50s to near 60 across the region.

The start of the weekend looks warm and dry, though models are
hinting at the potential for a northeast to east wind event in the
Sierra. While current models don`t look overly strong a few gusts
up near 30 mph are possible late Friday night and early Saturday
morning. Impact here would be increased wave heights into the
west shore of Tahoe. Brong

LONG TERM...Sunday through Wednesday...

No large changes were made to the existing forecast which is
largely benign. The east Pacific ridge remains the dominant
weather feature and is expected shift eastward Sunday/Monday.
Expect warming temperatures into the low/mid 70s for western
Nevada and low 60s for Sierra Valleys.

Temperatures fluctuate more Tuesday and Wednesday as a dry,
backdoor front moves through the region. Winds will increase
becoming breezy and keeping conditions feeling cooler than the mid
60s that are forecast. Otherwise, expect river flows to trend
higher, especially for the Walker and Carson river systems which
have fewer control measures than the Truckee River system. Water
temperatures will remain dangerously cold, and it is recommended
to stay out of rivers during these elevated flows.

Models become much less reliable past Wednesday, but do hint at
the potential of a pattern shift. GFS is more realistic showing a
break-down of the ridge with northern Pacific troughs moving
through the Pacific Northwest. This scenario is more reasonable
than the EC which begins to translate the large ridge into the
inter-mountain West. Boyd

AVIATION...

Breezy to gusty conditions will continue into the evening for most
terminals and through the night for MMH. Rotors at RNO presented a
LLWS threat that has largely diminished since surface winds have
phased with winds aloft. Still, expect speed and directional shear
to remain for Sierra locations through the day where terrain
induced surface winds are transverse to faster flow aloft.
Mountain wave turbulence will continue overnight with ridge winds
remaining elevated.

Precipitation chances have largely decreased, but there could
still be a few Sierra showers to contend with. Mountain
obscurations continue to be certain, but will improve tomorrow as
drier air moves over the ridges.

Winds decrease tomorrow, but remain breezy with flow becoming more
northerly. Flight conditions improve this weekend as high pressure
moves over the region allowing for warming temperatures. The only
threat to operations will be any thaw of snow near runways that
refreezes on runway surfaces overnight; TVL, TRK, MMH. Boyd

&&

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

$$

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


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