Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 260844

Area Forecast Discussion
National Weather Service Pocatello ID
244 AM MDT FRI AUG 26 2016

.SHORT TERM...Today through Monday...Partly to mostly cloudy
skies noted across the Upper Snake Highlands and portions of the
Central Mountains this morning. Isolated showers noted as well and
may continue across areas near Island Park, Monida Pass, and
Driggs. For the rest of today, an isolated thunderstorm
possibility exists this afternoon/early evening across the Eastern
Highlands and along the Continental Divide. Light precipitation
amounts are forecast.

Saturday and Sunday becomes warmer, drier and without opportunity
for rain across Southeast Idaho. This is the result of high
pressure in place at the surface which is expected to be centered
just to our east. A temperature increase of 2 to 6 degrees is
expected between Friday and Saturday. A similar trend is expected
for Sunday`s temperatures with little change in conditions for
Monday. NP/RS

.LONG TERM...Tuesday through next Friday...On Tuesday, the center
of high pressure is expected to be shifted to our southeast as low
pressure advances toward us from the northwest. May see some rain
showers in the Central Mountains by late Tuesday into Wednesday
but right now it`s a bit early to be confident in that. Several
troughs of energy progress eastwards from the broader trough to
our west next week, which should bring areas of rain and
thunderstorms at times. It will be a matter of timing these pulses
of energy out and placing them as next week nears. Expect to have
a cold front pass through at some point as well - in the mid to
late week time frame. Increasing winds and cooler temperatures
will occur in association with this front. NP/RS


.AVIATION...Isolated convection possible this afternoon over
the mountains northeast of KSUN and eastern highlands along the
Idaho and Wyoming border. Areas of smoke from local fires may reduce
visibility near KIDA/KDIJ and Alpine. Smoke will be the main concern
again on Saturday. Convection is not expected to affect TAF sites
Saturday. RS


.FIRE WEATHER...This will be the last day under the influence of a
low pressure trough that lingers across Montana into southeast
Idaho. There is a fair amount of moisture passing through Montana
today, so we feel prudent in keeping a slight chance of a shower or
thunderstorm over the mountains northeast of Sun Valley, near the
Montana border from Monida Pass to Island Park, the Driggs/Victor
area which can be a favored area for convection to show up, and Bear
Lake. There are still some northeasterly surface winds in the Upper
Snake Plain and along the Interstate 15 corridor this morning, but
the pressure gradient has already weakened quite a bit and as we
move into the afternoon hours expect a more typical west-southwest
wind in the Snake Plain and the Eastern Highlands along the Wyoming
border. The Central Mountains including the Salmon-Challis Forest and
northern Sawtooth Forest will experience north to northwest winds.
Early morning winds in the Eastern Highlands will favor some east-
southeast winds below inversions, while the ridge tops will see more
influence of southwesterly winds aloft. Saturday afternoon winds
pick up in the Snake Plain with gusts in the 15-20 mph range. Expect
some of these wind gusts will extend into the active fire areas of
Toponce, Henrys Ck., Black Fire and Tie Fire. Our Red Flag Criteria
is gust to 30 mph in the Snake Plain zones 425/410 and gusts to 25
mph for all other mountain zones, combined with RH at or below 15
percent for all zones. It does not look like we will reach that
criteria, but some increase in afternoon gusts is expected. The
upper level flow turns more westerly beginning Saturday and
continuing through probably Tuesday. Temperatures warm in the lower
valleys back to the middle and upper 80s. Relative humidity in the
lower valleys begins to sneak back into the single digits and lower
teens. Elevated ridge top winds are expected in Lemhi County zone
476 both Sunday and Monday. Models are showing some consistency in
bringing in a new storm system off the Pacific around Tuesday night
and Wednesday. That is both good and bad; we will see more winds and
convection, but it also brings the hope of precipitation for some
really dry fuels. SURVICK


.PIH Watches/Warnings/Advisories...

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