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Area forecast discussion 
National Weather Service Elko Nevada
211 am PDT sun Sep 21 2014 upper level low will bring widespread rain and
thunderstorms to Nevada today. Drier weather will begin returning
Monday as the low moves away. After a bit of cooling
today...warmer weather will return by middle week.


Short through Tuesday. Upper level low is the main
story. At present it is centered in central California. A warm
front like feature extends east-northeast from it and is focusing
stratiform precipitation across central Nevada...spreading
northward slowly. South of this feature the air mass is more
unstable with showers and thunderstorms. As we head through the
day the warm front-like feature will move northward toward the
Idaho border spreading rain with it this morning. This feature
appears to weaken this afternoon but by then most of the County Warning Area will
be in the unstable air mass south of it as the upper level low
center moves into northwestern Nevada. This should result in
continued showers and thunderstorms. Storm motions look
decent...and with plenty of forcing and a bit of shear some severe
weather is possible. Also some flooding issues possible but see
the hydrology section below for more details.

As the low heads northeast into Idaho this evening forcing should
quickly wane both on the broad scale and mesoscale and moisture
levels should fall shower/storm coverage will quickly
diminish overnight.

Shortwave ridge builds into Nevada on Monday...but some lingering
moisture/forcing/cyclonic curvature will remain over the far have some isolated/scattered showers/T-storms in
that area while the rest of the County Warning Area should dry out. The ridge
shifts only slightly east on Tuesday with a broad southwesterly
flow bringing ever drier air into the area with no
Tuesday should be dry and mostly sunny.

Temperatures today will be considerably cooler than recent days
thanks to the clouds and rain. They should rebound to near normal
on Monday and bounce back above Tuesday with the ridge and
southwesterly flow aloft. Rcm

Long term...Tuesday night through next Sunday. Major models agree
nicely Thursday evening then differences appear. Big story from
Tuesday night through Thursday morning is dry southwest flow aloft.
As this trough responsible for this digs and closes off the socal picks up fairly substantial eastern Pacific sub-tropical
moisture...driving up precipitable waters into the remainder of the long term
forecast period. Starting Thursday afternoon...there is enough relative humidity
and dynamics and instability to warrant showers or thunderstorms
in every period through next Sunday. However...the best
instability will be over the southeast half of the forecast area
or in the eastern 100 miles or so of the state. Front moves
through the region on Thursday with gusty winds and significant
drop in temperatures. Will feel more like fall next weekend for
the first time this season.


Aviation...widespread area of showers and thunderstorms over most
of central...eastern...and northern Nevada through at least 06z
Monday. Precipitation starts to move east after that...but will still
affect keko and kely through 12z Monday. Generally...VFR
conditions expected at all sites...but now and then may drop to
below 5sm in moderate to heavier showers. Also...this system has a
history of producing wind gusts to between 30 and 40 knots...even
without thunder...some reducing visibility in bldu.


Fire concerns today with widespread rain and wet
thunderstorms. Gusty winds may become an issue by the middle of
the week as a Pacific front approaches. Rcm


Hydrology...upper level low with nice tropical moisture source
will move across the region today. Already a potent band of
moderate to heavy rain across central Nevada at this hour with a
pseudo warm front...with decent fgen in this area. This fgen band
should move north across the rest of the County Warning Area this morning with the
convective unstable air mass south of it advecting across most of
the region. Thunderstorms this afternoon will be very
common...especially with precipitable waters locally over 1 inch...but storm
motion should be decent. However...any training can cause flooding
issues so have left Flash Flood Watch unchanged. Already at this
hour mesonet stations in central Nevada have recorded nearly an
inch of rain in some places with radar estimates of over an additional rain will only cause problems in these areas.
The flood threat will quickly dwindle this evening as the low
moves northeast into Idaho and moisture levels drop on westerly
winds behind it. Rcm


Lkn watches/warnings/advisories...
Flash Flood Watch through this evening for northeastern Nye
County...northern Elko County...northern Lander County and
northern Eureka County...northwestern Nye County...Ruby
Mountains/East Humboldt Range...south central Elko County...
southeastern Elko County...southern Lander County and southern
Eureka County...southwestern Elko County...White Pine County.




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