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000
FXUS66 KOTX 072326 CCA
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
326 PM PST Fri Mar 7 2014

.SYNOPSIS...
With the flooding event essentially over today...there will be a
break in the active weather pattern through Saturday. Saturday
will be the warmest day as the next cold front approaches the
Pacific Northwest coast. This front will move through Saturday night
and Sunday producing rain and breezy conditions...followed by a
potentially much strong wave impacting southeast Washington Monday.
High pressure will then build in for the middle of next week for
drier and warmer conditions.

&&

.DISCUSSION...

Tonight and Saturday...Ridge of high pressure migrates east with
time. By Saturday afternoon the axis is well positively tilted,
flattened out, and centered roughly over Southern Idaho which
allows the moisture stream juxtaposed along the west side of it to
be within closer proximity of the Cascades and Northern Border
locations. With this in mind a scenario involving increased cloud
cover and pops near the cascades and to the north near the Southern
British Columbia border remain a good way to go. Otherwise until
the ridge exits some stratus/fog formation tonight that lingers
over into Saturday morning along with minimal pops, qpf, and
clouds for light convective showers that diminish overnight and
into tomorrow morning remain. /Pelatti

Sat Nt through Sun Nt: Following a warm and dry day Sat for much
of Ern Wa and N Id, we`ll have to deal with two main waves...the
first one being a quickly moving cold fropa Sat Nt followed by a
short break...then another front impacting SE Wa Sunday Nt. Our
lowest level of confidence as far as timing and pcpn amnts is this
second feature lifting NE out of Oregon. The first cold front Sat
Nt, though dynamically shows signs of lift forced by isentropic
ascent under jet-forced ascent aloft, the quick passage as well
as the strongly veering winds will keep the heaviest pcpn amnts
limited to the mtns of NE Wa, N Id and near the Cascade crest.
Snow levels will remain high enough to not pose any threat of
accumulating snows to any of the main regional passes. The Sunday Nt
short-wave trof shows cyclogenesis along what`s left of the tail
end of the Sat Nt/ Sunday front that stalls, then lifts north
through Ern Oregon and into the Srn part of the Id Panhandle. The
GFS brings the pcpn farther north than the SREF, ECMWF, and NAM...
with the NAM keeping nearly all its pcpn limited to Oregon. The
stronger GFS has the most impressive pcpn amnts, likely due to its
Nw upslope into the Camas Prairie region, forcing aloft from an
inbound vort max as well as an impressive couple upper jet
structure that, if this pans out, would produce a band of heavy
rain from the Nrn Blue mtn, to Lewiston, Pullman and especially
the Camas Prairie of Idaho. Snow levels should not be an issue,
likely not falling below 5000 feet with this pcpn. Coordination
with nearby NWS fcst offices has lead to a consensus that the pcpn
likely won`t be as heavy or as far north as the GFS, but the trend
will be watched closely the next 36-48 hours. bz

Monday through Wednesday night...An upper level trough will swing
through the Inland Northwest on Monday for cooler and showery
conditions. Ahead of this trough a moist short wave out of Oregon
swings northeast clipping southeast Washington and the Camas
Prairie. Models show the potential for as much as a quarter to a
half inch of precipitation for Pullman, Lewiston, and Winchester
with snow levels around 4500 feet on Monday falling to 3000-3500
feet Monday evening. However most of the precip will fall with the
higher snow levels such that no significant high elevation snow is
expected.  Precipitation amounts will be much less north of these
areas where precipitation will be more showery in nature with mid
level westerly flow most favoring the Cascade crest and Idaho
Panhandle where upslope flow will enhance shower activity. Convective
parameters from the GFS show uncapped CAPE`s OF 200 J/KG so a
stray thunderstorm is not out of the question. Meanwhile in the
lee of the Cascades downslope flow should keep conditions dry for
the Okanogan Valley, as well as the Moses Lake and Wenatchee
areas. The Inland Northwest will dry out and stabilize overnight
Monday through Wednesday as high pressure moves over the region. A
weak wave moving through the ridge could bring a few showers to
the Cascades Wednesday night but models show the best chances
north of the Canadian border. JW

Thursday through Friday night: The picture in the far extended has
not got any clearer. While a weather disturbance looks to affect
the Inland Northwest during the latter portion of the work week,
which day this occurs is the tough part. With several days to get
this sorted out will not make too many changes to what was already
forecast. This means slight chances for mountain and valley
rainfall, with temperatures near seasonal averages (perhaps
slightly below by Saturday morning). ty

&&

.AVIATION...
00Z TAFS...High pressure ridge building into the area allows for the
brief clearing ahead of frontal zone oriented on its back edge.
Abundant low level moisture leftover from recent rainfall and
associated snow-melt and the low level south/southeast flow may
allow for stratus/fog formation in proximity along the Spokane river
and northern parts of the Columbia basin along with many of the
sheltered mountain valleys. This fog/stratus is expected to decrease
some during the early part of the day but clouds will invade the sky
from the west through the day Saturday. Those clouds Saturday will
thicken over the day and lower and show the approach of the next
weather system expected to bring more rain into the aviation area
generally after 00Z Sunday. /Pelatti

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        34  54  43  53  36  48 /   0  10 100  80  30  40
Coeur d`Alene  33  53  40  50  34  47 /   0  10 100  90  30  40
Pullman        36  55  43  54  38  49 /   0   0  90  90  50  60
Lewiston       35  60  46  57  42  55 /   0   0  90  90  70  70
Colville       33  55  39  52  34  51 /  10  10 100  70   0  40
Sandpoint      32  49  38  48  35  46 /  10  10 100 100  20  50
Kellogg        32  47  38  46  35  44 /  10  10 100 100  60  80
Moses Lake     36  64  46  60  35  56 /   0  10  60  30  10  10
Wenatchee      36  55  41  56  37  54 /   0  20  60  30   0  10
Omak           33  54  38  54  30  51 /  10  20  90  30   0  10

&&

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

$$