Area Forecast Discussion
Issued by NWS Spokane, WA

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034
FXUS66 KOTX 222142
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
242 PM PDT Thu Aug 22 2019

.SYNOPSIS...
Clouds and isolated showers will decrease across extreme eastern
Washington and north Idaho through the evening with a few showers
Friday afternoon near the Canadian border. Otherwise a jet stream
will remain over of eastern Washington and north Idaho through
the weekend allowing for breezy and dry conditions. High pressure
will build over the work week allowing for a warming trend coupled
with continued dry weather.

&&

.DISCUSSION...
Tonight through Saturday night: Drier northwest flow will move
into the region this evening, allowing the clouds and lingering
showers to depart. Gusty north and northwest winds in the Okanogan
Valley and Cascades will dissipate overnight, giving way to
lighter winds as high pressure builds into the region. On Friday,
the flow aloft flattens as a shortwave track across B.C. and
brushes the Inland NW with high clouds and a small chance of
showers across the northern mountains while temperatures warm a
few degrees. By Friday night into Saturday, the westerly flow
aloft tightens while a strong 120kt jet slices across the region.
Some of these winds will mix to the lower levels with gusty winds
developing Saturday afternoon and evening. Gusts of 30-35 mph are
possible from the Cascade valleys, Waterville Plateau, Columbia
Basin into the Spokane area and Palouse. These winds bring will
usher in drier air with borderline dry/breezy criteria possible
for fire weather concerns. Temperatures will warm a few more
degrees on Saturday, bringing values near seasonal normals. As
winds taper off Saturday night and dry in place, should experience
cooler overnight lows by early Sunday morning. /rfox.

Sunday through Thursday: Per perusal of deterministic and
probabilistic models a cold front passes through a somewhat zonal or
northwest flow on Sunday allowing for continued breezy conditions
and slight drop in temperatures. During a good portion of the
workweek the ridge off the coast responsible for orientation of the
northwest flow into Eastern Washington and North Idaho amplifies and
the ridge axis moves closer to the coast, this will result in a
generally dry forecast with a warming trend. Probabilistic ensemble
model runs suggest this trend will linger thru the workweek at least
with an occasional deterministic model run such as the latest GFS
suggesting the ridge moves further inland, narrows and becomes more
negatively tilted. This reorientation of the ridge could allow a
trajectory of approach up from the south which could trigger
convection in the form of showers and thunderstorms but for now will
keep the trend suggested by the NBM which keeps the workweek
forecast dry. /Pelatti

&&

.AVIATION...
18Z TAFs: Anticipate improving conditions in the short term.
Areas of MVFR cigs at KGEG-KSFF should improve by early afternoon,
although a VFR deck will linger from KGEG-KCOE and KPUW through
much of the afternoon under the upslope southwest-west low level
flow. Light showers over the central Panhandle mountains will
decrease this afternoon. Winds at KEAT will be remain northwest
around 10kt. Clouds will dissipate this evening to mostly clear
VFR conditions under light winds. /rfox.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  81  56  81  51  79 /   0   0   0   0   0   0
Coeur d`Alene  54  80  55  81  51  78 /   0   0   0   0   0   0
Pullman        50  80  53  79  48  76 /   0   0   0   0   0   0
Lewiston       57  88  62  87  58  83 /   0   0   0   0   0   0
Colville       45  86  45  87  42  84 /   0  10   0   0   0   0
Sandpoint      52  78  51  79  48  76 /   0  10  10   0   0   0
Kellogg        55  78  58  76  54  73 /  10   0   0   0   0   0
Moses Lake     52  86  55  86  52  84 /   0   0   0   0   0   0
Wenatchee      59  85  61  82  59  82 /   0   0   0   0   0   0
Omak           57  83  56  84  54  82 /   0  10   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.

&&

$$



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