Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 262340
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
440 PM PDT Mon Sep 26 2016

.SYNOPSIS...
A mild and mostly dry weather pattern is expected through
Wednesday. Temperatures will be above average, with several days
of highs in the mid 70s to mid 80s. Cold front passage on Tuesday
will produce breezy winds down the Okanogan Valley. A pattern
change is expected to arrive late in the week with chances for
showers beginning Thursday and continuing into the weekend. By
Saturday and Sunday, afternoon temperatures will likely be in the
60s.

&&

.DISCUSSION...

Tonight...The ridge of high pressure which kept yesterday and today
quite sunny and warm begins to erode tonight with a cold front
approach and the onshore flow ahead of it on the west side of the
Cascade Crest. Nothing in the way of precipitation is expected
tonight but some thin mid and high level clouds that invade the sky
tonight signaling the approach of the front may increase thickness
somewhat overnight. Additionally the tightening of the pressure
gradient across the cascades due to this scenario will allow for
some increase in the generally west winds blowing across the
Cascades. /Pelatti

Tuesday:
A dry cold front is expected to move through the region beginning
Tuesday morning. The main issues with front as it passes will be
the increase in winds particularly in the Cascade Gaps. Wind
gusts in that region can expect to reach 40 MPH. Wind gusts in
along the Waterville Plateau can expect wind gusts in the 20 MPH.
Temperatures will cool off a bit on Tuesday with highs generally
in the upper 70s to lower 80s.

Wednesday through Friday:
As the cold front exits the north-south gradient will allow for
the Okanogan valley experience some breezy winds with gusts up to
around 25 MPH. This will slowly progress into the Northern Idaho
Panhandle by wednesday afternoon and bring some slightly higher
winds to the Purcell trench of around 20 MPH. A Low will also be
dropping in off the coast of Washington. This will setup a
southerly flow pattern for the region. This will bring moisture
into the region increasing the clouds and bringing chances of
precip to mainly extreme Eastern Washington and the Idaho
Panhandle. The increased cloudiness will reduce the highs into the
mid 70s to upper 60s. The lows will in the low 40s to upper 30s.
/JDC


Friday night through Monday: An upper trough migrates into the
Pacific Northwest this period, continuing to provide shower
chances and ushering in cooler air. Models indicate two or three
shortwaves rounding the upper trough and crossing the area to
provide the precipitation chances. While precise timing and
coverage is less than certain (with some disagreement on the
evolution of these individual features) I did increase PoPs some
for Sunday night into Monday when one of the more potent
shortwaves may pass. Expect some breezy conditions, especially
Saturday as the cooler air is infiltrating the region.
Temperatures themselves will be dropping to below seasonal norms
through the period, with a few areas not getting out of the 50s.
This will be accompanied by lowering snow levels: average snow
levels between 5-6kft are projected. This could mean some higher
elevation/back country snow and maybe light accumulation even
around the higher Cascade passes and Sherman Pass. /J. Cote`


&&

.AVIATION...
00Z TAFS: A weak cold front will track into Central and Northeast
Washington into the Idaho Panhandle on Tuesday. This front will
bring a band of mid and high clouds as well as an increase in
winds down the Okanogan Valley. Dust lofted at times from ongoing
construction projects near KPUW will pass over the KPUW ASOS
sensor from time to time and result in unrepresentative reports of
some low clouds and haze at times that is in fact just brief bits
of lofted dust and really not impacting the true visibility and
ceilings at KPUW. JW

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  79  52  79  53  76 /   0   0   0   0  10  10
Coeur d`Alene  54  78  52  79  52  76 /   0   0   0   0  10  10
Pullman        53  79  51  81  51  75 /   0   0   0   0  10  10
Lewiston       59  85  57  85  57  80 /   0   0   0   0  10  10
Colville       49  79  45  79  47  78 /   0  10   0   0  10  10
Sandpoint      48  75  47  74  48  74 /   0  10   0  10  10  10
Kellogg        51  76  50  79  50  74 /   0   0   0   0  10  20
Moses Lake     53  81  49  80  48  78 /   0   0   0   0   0   0
Wenatchee      58  79  53  78  52  77 /   0   0   0   0   0   0
Omak           54  79  47  78  49  78 /   0  10   0   0   0   0

&&

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

$$



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