Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 281139
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
439 AM PDT THU AUG 28 2014

.SYNOPSIS...
The weather will begin a cool down today with an increase of
clouds and locally breezy winds. The next storm system will arrive
during the holiday weekend. This will result in breezy to windy
conditions along with an increased chance for mountain showers
along with temperatures dropping below normal.

&&

.DISCUSSION...
Today, tonight and Friday: Westerly flow aloft prevails across the
Inland Northwest as the strong upper level ridge weakens and get
shunted south. This will also begin the gradually cooldown for the
rest of the week. There will be a few disturbances rolling through
the upper flow that will give the region an increase of cloud
cover and the chance of showers. Currently one weak impulse is
skirting over southern BC with isolated showers and thunderstorms
this morning. There is a small chance of showers may brush near
the Canadian border and north Idaho early this morning as this
impulse slides east. Mid level moisture will linger through the
day as a stronger shortwave swings in from the BC coast inland
and pushes a thinning frontal boundary along the Canadian border.
Surface based instability increases across the northern mountains,
and there is a renewed chance of showers late this afternoon and
early evening. Southwest to westerly surface winds will pick up
this afternoon especially in the lee side valleys and across the
Columbia Basin with local gusts to 25 mph. Expect temperatures
about 5-10 degrees cooler than yesterday. Late tonight, the
frontal boundary exits the region and a shortwave ridge builds in.
Winds will taper off in all by the lee side valleys as downslope
flow gets enhanced. On Friday, the next stronger shortwave will
dig a little further south and push a frontal boundary into
Washington. Expect an increase in clouds and a chance of showers
across the Cascades by Friday afternoon. Westerly winds will
become breezy again in the afternoon, as temperatures continue to
cool a few more degrees to the upper 70s to lower 80s, which is
pretty close to seasonal normals. /rfox.

Friday night through Thursday...Models are in good agreement in
depicting a more progressive...somewhat more showery and
definitely cooler and windier pattern from this weekend well into
next week. A series of fast moving and generally weak short waves
will clip through the forecast area Friday night and Saturday...on
or about Monday...and again on or about Wednesday with the
Wednesday trough shaping up to be a stronger system. The
interregnum periods between these waves will feature a northwest
or zonal flow regime.

None of these disturbances appear to be strong enough or dynamic
enough to create any widespread or sure bet precipitation
threats...but all have the potential for scattered showers and
isolated afternoon thunderstorms over the mountains arcing the
Columbia Basin. In the basin itself the main issue will be breezy
and occasionally gusty winds as a persistent westerly gradient
and advection of a cooler maritime air mass sets up and continues
through the period.

Expect a generally breezy Labor Day weekend with temperatures
reaching only into the 70s at most populated low land locations
from Saturday through Monday...and continuing on into the next
work week as this progressive Pacific pattern prevents any
significantly warmer air masses from becoming established before
being eroded by the next wave. /Fugazzi

&&

.AVIATION...
12z TAFS: Will see some wave cloud development of high clouds over
the Cascades this morning, otherwise mid level moisture will be on
the increase across the northern mountains giving way to a chance
of showers during the afternoon and early evening. This should
remain north of the TAF sites. Gusty west to southwest will
develop between 21z and 29/02z. Otherwise expect VFR conditions.
/rfox.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        83  58  81  53  72  49 /   0   0   0   0  10  10
Coeur d`Alene  82  55  81  53  71  47 /   0  10   0  10  10  10
Pullman        82  51  81  49  71  44 /   0   0   0  10  10  10
Lewiston       89  61  88  59  77  54 /   0   0   0  10  10  10
Colville       87  53  82  48  75  44 /  10  10  10  10  30  20
Sandpoint      81  51  78  51  69  41 /  10  10   0  10  30  20
Kellogg        79  57  77  52  67  48 /   0   0   0  10  20  20
Moses Lake     89  56  85  51  77  48 /   0   0   0   0   0   0
Wenatchee      87  62  82  57  76  56 /   0   0   0   0  10  10
Omak           86  56  83  54  76  51 /  10   0  10   0  10  10

&&

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

$$




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