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Area forecast discussion 
National Weather Service Spokane Washington
430 PM PDT Monday Sep 15 2014

Synopsis...
unseasonably warm temperatures will be across the inland northwest
through Wednesday as high pressure remains over the region. A weak
cold front will likely arrive on Thursday cooling temperatures
closer to normal. There will also be a chance for light mountain showers
Thursday into Friday morning with the passing front. Warm and dry
conditions will likely return for the weekend.

&&

Discussion...
tonight and tuesday: high pressure will be over the region for the
next 24 hours, although it will weaken slightly as a shortwave off
the Oregon coast pivots into it. A band of high level moisture
associated with the shortwave will sweep in from the south
overnight into Tuesday. The lift is weak especially as the
shortwave falls apart as it tracks into the upper ridge axis
position. Most of this moisture will be above 10k ft, so the
threat of any precipitation will be minor. But the best if any
chance will be across the Blue Mountains Tuesday morning and then
into central Idaho Panhandle by Tuesday afternoon. Otherwise
anticipate some areas of virga or isolated sprinkles with the
cloud band across southeast Washington and southern Idaho
Panhandle. Meanwhile, low level temperatures will continue to
rise, about 2 to 4 degrees warmer on Tuesday. This would make
Tuesday the warmest day of the week. Winds will be light and
mostly east/northeast tonight into Tuesday morning, with southwest
winds creeping into the southern Columbia Basin and Palouse by
Tuesday afternoon. /Rfox

Tuesday night through Thursday night...in the big picture a
splitting trough will move into the eastern Pacific by Tuesday
afternoon. By Wednesday afternoon the southern portion of the
split closes into a cut-off low with the best moisture and
dynamics staying well south of our area. What this will do is drag
a weakening trough through southern b.C. Wednesday night and
Thursday with best forcing staying in central b.C. There will be
some mid level moisture that will move into the area Wednesday
night and Thursday.

For Tuesday night the models keep showing a weak wave moving
out of northeast Oregon and just brushing our southeast zones.
I kept some very low end pops through the night, but am far from
impressed and thinking at this just may be some increasing mid-
level clouds.

Wednesday night through Thursday night...slight chance to chance
pops over the Cascades Wednesday night...then the chance for
precipitation will track across the northern mountains and Idaho
Panhandle for Thursday and Thursday night. Precipitation as mainly
showers... however there appears to be enough mid level
instability to introduce a few lighting strikes for the far
northeast mountains and Idaho Panhandle zones late in the day
Thursday. Confidence is much better for some light shower than any
lightning. Any precipitation should be a tenth or less. A slight
up tick in the southwest winds can also be expected Thursday
afternoon with sustained winds around 10mph. /Tobin

Friday afternoon through Tuesday morning: the exiting mid-week
trough will be replaced by another ridge of high pressure for the
weekend. While the ridge looks to keep things pleasant all
weekend, another trough will approach early next week.

The ridge should bring warming temperatures, with afternoon
readings topping out 10 to 15 degrees above normal (widespread
80s). The approach of another trough off the Pacific northwest
coastline should begin to bring those temperatures back towards
normal, but will still be 3 to 7 degrees above (mid/upper 70s). TY

&&

Aviation...
00z tafs: a warm and dry air mass will remain over eastern
Washington and north Idaho through 00z Wednesday with light
winds. Smoke from fires near Mt Hood and in the basin will result
in scattered high smoke over a large portion of the inland
northwest. High clouds from a disturbance moving north along the
coast will result in increasing high clouds through the night.
There will be a small chance for showers near the Cascades and to
a lesser extent the Blue Mountains and southern ID Panhandle.
/Tobin



&&

Preliminary point temps/pops...
Spokane 54 85 56 83 57 79 / 0 10 10 10 10 20
Coeur D'Alene 51 85 52 83 53 78 / 0 10 10 10 10 20
Pullman 50 84 53 84 53 79 / 10 10 10 10 10 10
Lewiston 60 90 61 89 61 84 / 10 10 10 10 10 10
Colville 46 90 50 83 51 81 / 0 0 10 10 20 20
Sandpoint 41 83 47 78 48 75 / 0 10 10 10 10 30
Kellogg 50 83 54 80 53 75 / 0 10 10 10 10 20
Moses Lake 51 87 56 86 58 84 / 0 0 10 10 10 10
Wenatchee 56 86 61 85 62 81 / 0 0 10 10 20 30
Omak 48 88 55 86 57 82 / 0 0 10 10 20 20

&&

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

$$

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