Area Forecast Discussion
Issued by NWS Elko, NV
FXUS65 KLKN 272057
Area Forecast Discussion
National Weather Service Elko NV
157 PM PDT Sat Aug 27 2016
.SYNOPSIS...Isolated thunderstorms are possible across White Pine
and northern Nye counties this afternoon. Otherwise, mainly dry
and warm conditions are expected through most of next week.A
cooling trend is expected next weekend.
.SHORT TERM...Tonight through Monday. A few towering cumulus and
possible cb of low vertical extent are popping over southeast
White Pine County and extreme southern "northern" Nye County this
afternoon. These will mostly be extinguished by sunset with the
exception of the area near the Utah line south of Great Basin
National Park where more mid level moisture is available.
The upper low driving this convection is centered near the Grand
Canyon this afternoon and another upper low is in the northeast
Pacific. The Grand Canyon low, according to the models, will fill
in and move east, with the Pacific low actually closing off and
dropping some upper cyclonic spokes toward the coast and then into
the interior west by Monday. This will largely result in dry
southwest flow into the Great Basin through the short term
forecast. A skinny ridge is built up ahead of the Pacific spokes
and allows temps to warm a degree or two Sunday and then into
Winds die down a bit with the upper ridge development.
.LONG TERM...Monday night through next Sunday.
Overall forecast confidence is good until Tuesday; thereafter
differences in 500mb short waves and eventually the main 500mb
long wave trof drop the forecast confidence to medium. 5-wave
pattern resembles a long wave trof offshore of the Pacific NW and
western Canada at the start of the period, before it lifts
northeast and a split flow setup develop over the eastern Pacific
Ocean. By the end of the period, this split flow is centered over
the western US, with 500mb trof axis over NV. This setup results
in a general dry pattern under southwesterly flow aloft. Although
both the GFS and EC disagree on the specific path of the 500mb
shortwaves that impact the area, they do agree that one lifts
northeast sometime on Tuesday, with another weak one late
Wednesday, and finally one on Thursday, before the main 500mb
trof axis setups just west of the CWA on Saturday. Each of these
shortwaves (and possible weak sfc frontal boundaries), pulls the
dry line a tad northward, but keeps the vast majority of the area
on the dry side of it. Now, previous runs (especially the GFS)
progged this main 500mb trof axis to pass through on Saturday.
They has since backed off, with now a passage on Sunday...with the
exception of the GEM which still progs a significant shortwave
passage on Saturday. Still, with the 5-wave displaying a split,
not confident in this either, as this could lead to a split in the
trof axis, with energy being left behind, and possibly developing
cut- off feature over the area.
A thunderstorm or two possible Tuesday in White Pine County and
along the UT/NV border due to some moisture being draw northward,
but chances are pretty small. Another small chance exist on
Thursday along the UT/NV but not impressed by this setup either.
Although chances increase on Saturday across the western areas,
especially near the ID/NV/OR border area, did scale back a little
since models are depicting a later trof passage. Also, added some
low pops to higher terrain over White Pine county, as some
moisture should be able to be drawn northward on Saturday.
With this expected pattern, winds will be breezy and gusty every
afternoon, especially across the higher terrain of central NV.
Although winds advisories are not expected, they could reach that
threshold in isolated areas of northern Nye county on Wednesday
afternoon. The bigger concern with this pattern is the combination
of gusty afternoon winds and low afternoon RHs. Many areas could
be under the gun for fire weather concerns during the period.
After above average highs on Tuesday, they drop to near or
slightly below average on Wednesday and Thursday due to height
falls. High temps remain steady on Friday, before climbing near to
above average in the east and falling slightly in the far west on
Saturday due to the approaching 500mb trof. Overnight lows should
start off above average before dropping to near or slightly below
average Thursday through Saturday mornings (40s).
.AVIATION...VFR with no issue for next 48hrs. Winds will remain light
with typical diurnal directional changes.
.FIRE WEATHER...Mostly dry and warm through Monday. Very isolated
dry storms may form over extreme southeast zone 455 and extreme
southern zone 457 today and into this evening. This may repeat
Sunday over extreme southern 457. Winds weaken through Monday as
an upper high pressure ridge forms over the district. Through
Monday...RH recovery will become increasingly poor as drier air
moves in and temps warm a little.
Outlook for midweek: A weak cold front moves into the area
Wednesday and winds over the southeast part of the district
increase to the 20s mph with gusts to near 30 mph. In addition,
min RH`s will be in the low double digits to single digits. RFW`s
may become necessary. A little moisture creeps into extreme Nevada
for some isolated dry storms along the Idaho and Utah lines.