Weather Service Report


908 
FXUS66 KOTX 290116
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
616 PM PDT TUE JUN 28 2016

.SYNOPSIS...
The persistent upper level ridge responsible for the current warm
conditions will begin weaken Thursday and on into this weekend
leading to increasing westerly winds and eventually moderating
temperatures back to near normal temperatures. Expect breezy
conditions to continue through the holiday weekend and into early
next week.

&&

.DISCUSSION...
Tonight through Thursday...

Tonight and Wednesday's weather will be fairly quiet as a high pressure
ridge axis over the Idaho Panhandle keeps a lid on most convection.
The northern Cacades being just west of the ridge have the best shot
of any showers and possibly an isolated thunderstorms through about
8 pm then most clouds will dissipate for clear skies and a mild night.
Wednesday looks to be overall the hottest day of this latest warm spell
with temperatures about 10 degrees above normal in the mid 80s to mid
90s and overall light winds. Wednesday afternoon and evening will
still have the potential for a garden variety isolated thunderstorm
in the north Cascades.

Wednesday night into Thursday changes begin to occur as an upper level
trough moves closer toward the Pacific Northwest. Cooler air will 
move across the Cascades and into the Okanogan valley producing west
and northerly winds respectively.  It will still be hot and dry on
Thursday with only a few degrees of cooling at best and little
cooling in the Idaho Panhandle.

The Cascade gaps will see a noticeable increase in winds at 10 to 20 mph
while still reaching around 90 degrees Thursday on the lower east slopes
and western Central Basin. The atmosphere will also start drying.
The combination of wind and dry weather means caution should be exercised
when working with any kind flammables as grass fires are easy to
start and get away this time of year. TC

Thursday night through Tuesday...Latest models have come into
reasonable agreement with the overall field of motion through the
next week. The upper level ridge responsible for the much above
average current temper regime will flatten in response to the
eastward shifting of the Gulf of Alaska closed low into western
Canada starting on Friday...with this upper low residing over
British Columbia during the holiday weekend and into early next
week.

The effect of this transition will be a general lowering of
heights or flattening of the weak ridge currently over the
northwestern United States. A generally dry zonal flow regime will
prevail with any associated dynamic support remaining north in
Canada. The sensible weather ramifications for the region include
a growing confidence that temperatures will moderate starting
Friday...settling back to seasonal normal or perhaps a few
degrees below normal Saturday through through Tuesday. No really
apparent cold fronts are expected...this evolution will be more
of a subtle shifting of the surface thermal trough to the east
into Montana.

This will also set up a persistent westerly gradient across the
region. Breezy conditions over the exposed terrain of the Columbia
Basin and especially near the Cascade gaps will be common most
afternoons and evenings through the holiday weekend. While
temperatures will moderate...conditions will continue to be dry
and the breezy winds will create a significant risk of rapidly 
spreading range fires if any are started through careless use of
fireworks (or any other cause for that matter).

With the deeper moisture and dynamics associated with the polar
storm track remaining to the north in Canada...there is currently
no compelling reason to forecast any precipitation for the holiday
weekend outside of some stray showers over the mountains near the
Canadian border. /Fugazzi

&&

.AVIATION...
00Z TAFS: VFR conditions expected for at least the next 24 hrs.
The afternoon cumulus will decrease over the next few hrs with
clear skies until tomorrow aftn when a few cumulus will pop again.
Light and variable winds expected. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        64  92  63  90  60  86 /   0   0   0  10   0   0 
Coeur d'Alene  59  92  59  89  57  86 /   0   0   0  10   0   0 
Pullman        54  90  55  87  51  85 /   0   0   0  10   0   0 
Lewiston       65  98  64  95  62  93 /   0   0   0  10   0   0 
Colville       55  94  56  91  54  87 /   0   0  10  10   0   0 
Sandpoint      52  89  53  86  51  84 /   0   0  10  10   0   0 
Kellogg        55  90  55  87  54  84 /   0   0   0  10   0   0 
Moses Lake     62  97  63  93  58  90 /   0   0   0   0   0   0 
Wenatchee      67  94  66  91  63  89 /   0   0   0   0   0   0 
Omak           62  95  62  92  59  89 /   0   0  10  10   0  10 

&&

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

$$

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Western Regional Climate Center, wrcc@dri.edu