Wildfire in Washington, September 5 to 29, 2022

Area Forecast Discussion
National Weather Service Spokane WA
348 AM PDT Mon Sep 5 2022

.SYNOPSIS...
Labor Day will be warm with mostly sunny skies. Afternoon
temperatures will be mainly in the 80s. Temperatures will warm
back into the 90s on Tuesday and Wednesday. The arrival of a cold
front late Wednesday and Thursday will bring locally breezy
conditions with temperatures cooling into the 80s.

&&

.DISCUSSION...
Labor Day and Tuesday: Still under the influence of lowering heights
and a flattening ridge, the Northwest will see slightly cooler
temperatures today with breezy Cascade gap winds tapering off
through the day.  Ridgetops along the northern edge of Washington
and far northern Idaho could see some gusty winds, but overall a
much quieter weather day ahead. Given the slightly calm winds at the
surface, smoke models have some improved smoke conditions across
eastern Washington and north Idaho (except near wildfires). Air
quality sensors have shown marked improvement over the last 24 hours
-- however this doesn't mean we're through with smoke impacts.

Tuesday with the exiting shortwave trough to the east, the ridge
centered over the Great Basin will begin to strengthen as it settles
into place for the remainder of the week. For the most part winds
will be light with a slight easterly component for the Inland
Northwest. Temperatures will run about 10F above normal for early
September. The environment begins to show quite the drying trend
with ensemble guidance percentiles highlighting the lower 10th
percentile for precipitable water and forecast soundings
indicating a very dry lower and mid layer. /Dewey

Wednesday through Sunday: The well-advertised mid-week short wave
is still on tap to pay a visit to the Inland NW on Wednesday.
The models are still differing a bit with the timing and
intensity of this wave. The front will have very little moisture
that it is bringing with it. But there is some high level moisture
from off the California coast that will wrap around the periphery
of the Great Basin high pressure, and move over our area on
Wednesday. This could bring a sprinkle to southeast WA, or
possibly even a thunderstorm over northeast Oregon which could
track across the Camas Prairie. But the bulk of this system will
be dry.

The timing of the front is critical for the wind potential of this
system. The slower timing (i.e. GFS) would allow temperatures
to surge into the 90s ahead of the front. This would cause
humidities to drop into the lower teens. More importantly, it
would allow momentum mixing from higher in the atmosphere, with
gusts in excess of 30 mph possible. The faster timing (i.e. NAM
and ECMWF) would keep us a little cooler on Wednesday. Humidities
won't be as low, and winds won't be as gusty. The new ECMWF
Ensemble mean gusts show most areas north of I-90 will gust into
the lower 30 mph range. A fire weather watch will be issued for
our entire area for instability Tuesday night and wind/RH on
Wednesday.

Cooler air moves into the region behind this front on Thursday as
winds come from the north. Temperatures should be about 12 degrees
cooler on Thursday and remain cool on Friday. Some locations will
start off Friday in the upper 30s with very dry air in place.

High pressure builds back into the area as a Pacific ridge phases
with the 4-corners high. So the weekend will see a bit of warming,
back into the 80s and lower 90s. Believe it or not, we could see
some clouds over the weekend that are the product of Tropical
Storm Kay. She's forecast to approach southern California and her
high level moisture may get pulled up into Oregon. RJ

&&

.AVIATION...
12Z TAFs: No aviation concerns the next 24 hours under VFR
condition. Thanks to nearby wildfires, brief visibility reductions
could impact PUW and LWS airfields, though confidence is quite
low. Better chances will come Tue and Wed for additional
smoke/haze. Cascade valleys including Wenatchee could see breezy
winds this morning. Elsewhere, light winds and clear skies. /Dewey

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        81  50  88  56  90  55 /   0   0   0   0  10   0
Coeur d'Alene  80  48  87  55  89  54 /   0   0   0   0  10   0
Pullman        79  47  90  55  90  48 /   0   0   0   0  10  10
Lewiston       88  57  95  65  98  64 /   0   0   0   0   0  10
Colville       83  40  88  45  89  48 /   0   0   0   0   0   0
Sandpoint      78  44  85  49  85  49 /   0   0   0   0   0  10
Kellogg        77  54  87  63  88  51 /   0   0   0   0   0  10
Moses Lake     84  47  89  54  92  55 /   0   0   0   0   0   0
Wenatchee      83  56  87  62  90  64 /   0   0   0   0   0   0
Omak           85  51  88  56  92  53 /   0   0   0   0   0   0

&&

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

WA...Fire Weather Watch from Tuesday evening through Wednesday
     evening for Colville Reservation (Zone 702)-East Portion of
     North Cascades National Park/Lake Chelan National
     Recreation Area (Zone 697)-East Washington Central Cascades
     (Zone 696)-East Washington North Cascades (Zone 698)-
     Eastern Columbia Basin  -Palouse  -Spokane Area (Zone 708)-
     Foothills of Central Washington Cascades (Zone 705)-
     Foothills of Northeast Washington (Zone 701)-Lower Palouse
      -Snake River (Zone 709)-Methow Valley (Zone 704)-Okanogan
     Highlands and Kettle Mountains (Zone 699)-Okanogan Valley
     (Zone 703)-Selkirk Mountains of Northeast Washington (Zone
     700)-Waterville Plateau (Zone 706)-Western Columbia Basin
     (Zone 707).

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