Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Elko Nevada
240 PM PDT Wednesday Aug 27 2014
Synopsis...high pressure will provide Nevada with warm sunny
afternoons and clear cool nights through Friday morning. Isolated
thunderstorms are expected on the higher terrain of Elko County
Friday afternoon. A trough of low pressure will bring gusty winds
and slightly cooler afternoon temperatures over the weekend.
Short term...tonight through Friday.
Only fair weather cumulus remaining over eastern Nevada, as low
pressure exits Utah to our east. Expecting a Crystal clear sky,
light drainage winds, and excellent radiational cooling tonight. As
such, leaned tonight's low temperatures toward the coldest available
guidance, even hedged below in some of the coldest valleys.
Strong high pressure ridge will provide Nevada with a clear sky,
light winds, and much warmer afternoon temperatures on Thursday.
Afternoon maximum temperatures finally back to where they should be for late
August, in the middle to upper 80s, with lower 90s returning to the
western zones near Winnemucca.
A bit warmer on Friday, with thickness increasing a bit more, and
a SW breeze of 10-20 miles per hour helping to mix the boundary layer. Expect
upper 80s to be common, with low to middle 90s from Battle Mountain
NAM/GFS are in good agreement placing modest instability across
Elko County Friday afternoon, so introduced isolated thunderstorms
to the forecast. Isolated convection will favor the higher terrain
of Elko County, but moisture will be limited, with precipitable water less than
0.75 inch. Most of what forms will be dry, producing mostly virga.
Long term...Friday night through Wednesday. A strong short wave
trough will sweep across the Pacific northwest and northern Nevada
Friday night and Saturday. Not much in the way of moisture with this
system. NAM/Euro show a little moisture and instability across
northeast and east central Nevada Saturday afternoon so included a
slight chance of afternoon/evening thunderstorms over the mountains.
Otherwise main effects that will be felt will be breezy to windy
conditions Saturday afternoon along with cooler temperatures. By Sunday
highs will mostly be in the 70s across eastern Nevada with some 60s
across northern Elko County. Temperatures will begin to recover on Monday
as upper ridge begins to build into the area with temperatures getting back
to near normal by Wednesday.
Aviation...few-sct cumulus across eastern Nevada through 03z. Otherwise
VFR all terminals with winds less than 10 kts.
Fire weather...high pressure ridge will provide the fire district
with a clear sky and light winds through Friday morning. Afternoon
temperatures will warm back to near or above normal levels, in the
upper 80s and lower 90s, with min relative humidity falling to less than 15% for
many fwz, 15-20% across Elko and White Pine counties. Winds will
remain light on Thursday, with SW winds increasing to 10-20 miles per hour
on Friday afternoon. Afternoon winds will remain well below
critical thresholds through Friday.
Models agree on developing modest instability across Elko County
Friday afternoon, so added isolated convection to the higher
terrain of fwz 469, 470 and 455 and also near Eureka. Moisture and
coverage will be limited, with precipitable water <0.75 inch, so expecting lal of
2-3 in these zones, with some isolated dry lightning strikes.
Scattered coverage, with lal of 4, and a better chance of
measurable rain, across northern sections of fwz 469 and 470.
Saturday...trough of low pressure will pass through the Great
Basin, providing strong and gusty west winds, with gusts over 30
miles per hour likely. However, afternoon temperatures on Saturday will be as
much as 10 degrees cooler than friday's readings, so min relative humidity is
expected to stay above critical levels across the northern fwz.
Min relative humidity still expected to fall to 9-14% across fwz 457, which is
the zone most likely to experience critical wind/relative humidity Saturday.