Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 291208
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
507 AM PDT SUN MAR 29 2015

.SYNOPSIS...
The storm track will retreat north into Canada today and Monday
producing mild weather for the Inland Northwest. A vigorous
spring storm system will bring another chance for showers and
strong winds to our region on Tuesday. Wind gusts exceeding 40 mph
will be possible Tuesday afternoon and evening. Wednesday through
next weekend looks to be showery with temperatures near normal.


&&

.DISCUSSION...

...STRONG COLD FRONT TO DELIVER WINDY CONDITIONS ACROSS THE INLAND
NORTHWEST TUESDAY AFTERNOON...

Today through Monday: A flat upper level ridge at 500mb will
reside over the Pacific Northwest today into Monday. Vancouver
Island and the southern coast of British Columbia will experience
periods of rain during the next couple of days as a plume of
subtropical moisture is directed into southwestern Canada. Small
chances for light rain will extend as far south as the mountains
of far north central and northeast Washington today and tonight,
but the majority of our forecast area should be dry under bands of
mid and high level clouds. There will be much less wind today and
Monday with the typical afternoon increase in southwest winds,
generally in the 10 to 15 mph range. /GKoch

Tuesday: A vigorous cold front will seep across the region
Tuesday morning with the upper level trough of lower pressure
moving in for the afternoon. Models are in good agreement with a
deepening surface low scooting across southern BC into southern
Alberta through the day on Tuesday. Models all show the surface
low bottoming out at around 992 mbs along the eastern Divide in
southern Alberta by the afternoon hours. This will set up a
strong surface gradient, which will coincide with a favorable
time of day for mixing potential. The surface gradient looks to be
a little bit stronger compared to this past Saturday`s wind event
and there were spotty locations with sustained wind speeds of
30-35 mph. This front will have the potential for similar wind
speeds, but on a more widespread basis. This will include anywhere
from the Wenatchee Area, across the basin and over into the
exposed areas of the southern to central ID Panhandle. Winds up at
850 mbs look to peak at around 35-40 kts, which would translate to
a gust potential somewhere in the range of up to 40-45 mph. There
is a good possibility that a Wind Advisory will be needed for
Tuesday afternoon, but is still a bit early for a highlight at
this time this far out in the forecast period.

A 500 mb cold pool aloft will also result in the atmosphere
destabilizing through the afternoon. Showers will develop out
ahead of the cold front through the morning on Tuesday with more
showers likely developing in the conditionally unstable atmosphere
through the afternoon hours. Best chances for showers are expected
across the eastern half of the forecast area. There will also be a
chance for thunderstorms in the afternoon across the Okanogan
Highlands over into the Northern Panhandle.

Tuesday night through Sunday: A cold upper level trough of lower
pressure will hang around through Thursday. The cold front on
Tuesday will usher in colder temperatures with temperatures
closer to or slightly below normal. The cold upper level trough
will result in afternoon showers with the potential for some soft
hail or graupel. Shortwave ridging of higher pressure moves in
Thursday night, but another upper level trough of lower pressure
looks to drop down into the region for Friday through the
weekend. This will keep temperatures slightly below normal with
more convective showers expected, especially during the afternoon.
/SVH

&&

.AVIATION...
12Z TAFS: A couple of weak upper level disturbances will over-top
our flat upper level ridge today and tonight. Bands of mid and
high level clouds with ceilings at or above 12 thousand feet are
expected. Some light rain/high elevation snow will be possible
over the mountains along the Canadian border, but is not expected
to impact airports in the region. /GKoch


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        59  41  63  42  54  33 /  10  10   0  10  60  20
Coeur d`Alene  58  39  64  40  53  32 /  10  10   0  10  70  40
Pullman        60  40  65  41  51  35 /   0   0   0  20  60  20
Lewiston       66  43  70  46  56  37 /   0   0   0  20  50  20
Colville       60  41  65  40  56  31 /  10  10   0  10  70  30
Sandpoint      56  38  59  38  51  33 /  10  10   0  10  80  50
Kellogg        54  39  63  40  47  33 /  10  10   0  30  80  50
Moses Lake     67  40  69  43  59  34 /  10   0   0   0  20  10
Wenatchee      65  44  68  44  58  38 /  10   0   0  10  20  10
Omak           64  39  66  40  60  32 /  10  10   0  10  40  10

&&

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

$$




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