Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 261130
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
430 AM PDT Fri Aug 26 2016

.SYNOPSIS...
Dry northerly flow aloft will be over the Inland NW today. Surface
winds will switch this afternoon to the west to southwest winds,
and this may effect spread of smoke from area fires. A strong cold
front is expected to bring gusty west winds Saturday and heighten
wildfire concerns once again. Seasonal temperatures return next
week with an increase chance for showers across the northern
mountains.

&&

.DISCUSSION...
Today through Saturday: A weather pattern shift can be expected
over the next 36 hours as high pressure and light winds get
replaced by the passage of a dry cold front with breezy winds for
Saturday. For today, expect a dry northerly flow aloft. The
remnants of a weak disturbance aloft will exit and drag the high
level clouds southward across southern ID. The surface high
pressure area will weaken and a thermally induced low pressure
trough will nose into the Columbia Basin. Pressure gradients will
still be weak, but a shift in winds is expected. The predominant
north to northeast winds experienced the last couple of days will
end and west to southwest winds will develop by early to mid
afternoon across the Inland NW. This will affect area wildfires
and the spread of any smoke from them. Cascade gap winds will
increase with speeds up to 10 to 15 mph. The flow aloft will back
to the west as a weather disturbance carves out a trough of low
pressure over central BC by Saturday. Mainly high level clouds
will spill south of the Canadian border tonight into Saturday. A
mostly dry cold front will sweep in from the northwest Saturday
afternoon. Instability is weak but enough lift is available for a
small chance of afternoon mountain showers Saturday afternoon near
the Canadian border, but most areas will remain dry. Some cooling
will develop over the northern Cascades on Saturday, but for the
most part temperatures will peak across the Columbia Basin,
extreme eastern Washington and north Idaho on Saturday with some
of the warmest weather of the week. The more noticeable change
will be the breezy winds, which will raise concerns near area
fires. West to southwest winds will steadily increase ahead of the
dry cold front, peaking with its passage late on Saturday.
850-700mb winds increase to 25-30kt and mix down with the cold
front leading to gusty conditions around 30 mph. Some patchy
blowing dust is possible along with more smoky conditions.
Sustained winds will range from 15 to 20 mph and this coupled with
low humidities in the teens late Saturday will lead to fire
weather concerns. A fire weather watch will expand to include not
only the central Idaho panhandle, Spokane area, the Palouse, but
also portions of the central Columbia Basin for Saturday afternoon
into the evening hours. /rfox.

Saturday night through Friday...Model guidance has made some pretty
good improvement over the past 24 hours on how to handle the
extended period. The first weather disturbance will move through
B.C. Saturday night and exits on Sunday. This will bring about a
pattern change to the Pacific Northwest. A second and much deeper
upper level low will move to just off the B.C. coast Sunday and
Sunday night and dumb bell around off the coast for a few days
before moving inland as a closed low sometime around mid-week.

Saturday night and Sunday...the cold front will track through
the forecast area Saturday evening. This will keep gusty
southwest-west winds elevated with gusts 25 to 30 mph through the
evening then finally subsiding early Sunday morning. Temperatures
will cool off, but only by about 5-10 degrees. As mentioned in
previous discussions moisture isn`t overly abundant, but there
will be low end chances for showers and a few lightning strikes
Sunday afternoon and Sunday evening.

Monday through Tuesday...It will be interesting to see how this
whole pattern evolves. The upper low will take up position off
the coast on Monday and send several weak waves through the
Pacific Northwest through Tuesday. South-southwest flow will allow
temperatures to rebound back into the lower 80s Monday and
Tuesday. And it will also allow deeper Pacific moisture to slowly
move into the region. Some afternoon convection will be possible
each afternoon with afternoon heating and the weak waves, but
these should be tied to the higher terrain and be spotty at best.

Wednesday through Friday...The closed low will start to move into
the region Wednesday and depending on what model guidance you
want to use the low will linger over the region through Saturday.
This will result in widespread showers and isolated thunderstorms
each day. Temperatures will drop into the 70s, which is on the
cool side of normal. Winds will be shifting direction on daily
basis and be gusty at times as stronger waves move through the
region. Tobin

&&

.AVIATION...
12Z TAFS: The Inland NW will be in a dry northerly flow. Some
scattered cumulus is possible over the mountains this afternoon.
Otherwise a band of high level clouds is exiting the region, but
could see an increase of mid and high level clouds this afternoon
and overnight. Winds will be light, but a distinct wind shift will
occur after 20z today from the northeast to the southwest. Smoke
from area wildfires may impact some of the TAF sites, including
near GEG/SFF during the overnight hours, although confidence is
low. /rfox.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        84  60  86  59  79  58 /   0   0  10  10  10  10
Coeur d`Alene  83  55  85  56  78  55 /   0   0  10  10  10  10
Pullman        85  52  87  54  80  52 /   0   0   0  10  10  10
Lewiston       90  59  93  64  88  61 /   0   0   0  10  10  10
Colville       88  53  88  52  80  51 /   0  10  10  10  10  10
Sandpoint      80  50  82  51  76  50 /  10   0  10  10  10  10
Kellogg        79  52  81  53  77  53 /  10   0  10  10  10  10
Moses Lake     91  59  92  58  84  56 /   0   0   0  10  10  10
Wenatchee      90  65  88  62  84  61 /   0   0  10  10  10  10
Omak           91  59  89  55  84  54 /   0   0  10  10  10  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Fire Weather Watch from Saturday afternoon through Saturday
     evening for Northern and Central Idaho Panhandle (Zone 101).

WA...Fire Weather Watch from Saturday afternoon through Saturday
     evening for East Washington Northern Columbia Basin (Zone
     673)-East Washington Palouse and Spokane Area (Zone 674).

&&

$$



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