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Area forecast discussion 
National Weather Service Spokane Washington
515 PM PDT Tuesday Jun 2 2015

Synopsis...

Cool and showery weather will linger over the inland northwest
through Wednesday with the best chance for showers in the
mountainous regions of the Idaho Panhandle and northern
Washington. Much warmer weather is expected Friday into the
weekend as a high pressure ridge returns to the region. Saturday,
Sunday and Monday will feel like Summer with afternoon
temperatures in the mid 80s to low 90s.



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Discussion...
tonight through Wednesday night...a broad upper trough will remain
over the region through Wednesday night before it finally moves
off to the northeast. A surface trough has deepened over north-
central Washington today and will continue to affect the Okanogan
Valley and Highlands tonight. This feature is allowing persistent
moderate rain to continue to fall over the northern portions of
Okanogan and Ferry counties this afternoon and high resolution
models keep a bulls eye of precipitation over this area through at
least midnight tonight. Some minor flooding has been reported and
considering that much of this area is already saturated from
recent thunderstorm activity, it will not take a lot of rain to
cause minor flooding. An areal Flood Advisory has been issued for
the above area until 06z tonight. The surface trough will begin to
move east after 06z and will continue to weaken overnight. While
the most persistent showers will be along the Canadian border,
isolated showers will be possible for the entire forecast area
during peak daytime heating Wednesday. A slight chance of thunder
remains in the forecast for Wednesday afternoon/evening for the
eastern zones where a few hundred j/kg of cape will be available.
Organized storms are not expected as shear values will be rather
low except for across the southeast corner where values up to 30
kts are forecast. Temperatures will be on a warming trend but
expect readings to be just a few degrees warmer on Wednesday, very
close to seasonal normals. /Kelch

Thursday: Thursday will be a day of transition over the inland
northwest. The models are in good agreement that broad trough over
the Pacific northwest will be sheared apart on Thursday with
another 500mb low being carved into Southern California. There
should be enough residual troughing left over the inland northwest
Thursday afternoon for terrain-based showers and thunderstorms.
The coolest 700-500mb temperatures will likely be along the
Canadian border, so the ridges near Republic, Colville, and Priest
Lake will have the best shot of scattered afternoon and evening
thunderstorms. Limited instability and shear should prevent these
storms from becoming strong. Look for thursday's temperatures to
rebound to near average for early June.

Friday through tuesday: it looks like well above normal
temperatures for the weekend and possibly into early next week as
the northern branch of the polar jet retreats well north of our
region. We have seen this Omega block pattern a couple of times in
the last 3 weeks with a cut-off low over California and a high
pressure ridge over southern BC, Washington and Idaho. There is
some question about how far north moisture will wrap around
the California low. Clouds and showers Sunday, Monday, and
Tuesday could be the wild card(s) in our forecast. If the wrap
around moisture stays south of our region as advertised by the
ecwmf, we could see widespread upper 80s to mid 90s Sunday and
Monday. The GFS and Canadian suggest a bit more cloudiness which
could keep high temps down a bit. /Gkoch

&&

Aviation...
00z tafs: a shortwave will track through southeast Washington and nrn Idaho this
evening btwn 00-08z bringing the threat for a few light showers
vcnty of Spokane to Lewiston. Cigs with this activity will
generally be arnd 6k ft or higher and any pcpn will be light. We
are seeing a few weak thunderstorms at this hour south of klws
and this activity will wane by 03z. A different story closer to
the Canadian border where a persistent shield of light rain will
deliver overcast skies with cigs ranging 4-6k above ground level. Trof remains
over region Wed aftn with a small potential for shallow convective
showers aft 21z but confidence not high any activity will move
over the terminals. Models also indicating the potential for sct-
bkn stratus across southeast Washington and skirting Spokane-cda 10-15z. This
carries low confidence for restrictions. /Sb

&&

Preliminary point temps/pops...
Spokane 50 70 50 74 53 82 / 20 20 20 10 10 10
Coeur D'Alene 49 69 48 73 50 81 / 40 30 30 10 10 10
Pullman 44 68 44 71 47 79 / 40 20 20 10 10 10
Lewiston 52 75 52 78 54 84 / 40 30 20 10 10 10
Colville 50 71 48 76 50 84 / 80 40 40 20 20 10
Sandpoint 49 68 46 73 49 78 / 60 50 40 20 20 10
Kellogg 45 68 44 73 47 79 / 50 40 30 10 10 10
Moses Lake 51 76 51 79 54 88 / 20 20 10 10 10 0
Wenatchee 55 74 55 80 57 87 / 20 20 10 10 10 0
Omak 50 72 50 78 52 87 / 80 50 30 10 10 10

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Otx watches/warnings/advisories...
Idaho...none.
Washington...none.
&&

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