Area Forecast Discussion
Issued by NWS Spokane, WA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KOTX 302338
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
438 PM PDT SUN AUG 30 2015

.SYNOPSIS...
Showers, thunderstorms and breezy winds will diminish through the
evening hours as a vigorous upper level weather system exits the
region. A cool, occasionally breezy and showery weather pattern is
expected much of next week.

&&

.DISCUSSION...

Tonight: Isolated to scattered showers will continue into the
early evening as the upper level trough of low pressure crosses
the region. Much of this shower activity will be located across
the eastern half of the forecast area. Isolated thunderstorms will
also be possible through the early evening. I don`t think we will
be able to generate enough instability for thunderstorms to be a
big threat. Strongest storms are expected to be across the
northern mountains with small hail, heavy downpours and gusty
winds to 40 mph possible.

Monday through Tuesday: Another shortwave trough will swing by the
region on Monday and Monday night. This system will mostly be a
glancing blow across the northern zones. The best dynamics will
remain well up into BC. A weak warm front will swing through on
Monday. This will increase mid and high level cloud cover. The
cold front will then swing in Monday night. Neither front shows
much lift and only some light showers will be possible. Best
chances for precip will be across the northern mtns. Temperatures
will see a slight warming trend, but will still remain near to or
slightly below normal. /SVH

Tuesday night through Sunday. A broad upper-level trough will
remain anchored over the Pacific Northwest during this time-
frame. Confidence is near to above normal that cooler temperatures
will be here to stay with afternoon highs in the 60s to 70s.
Overnight lows will largely be in the 40s to 50s with pockets of
30s in the northern valleys and on the highest peaks.
Precipitation chances will be centered around the timing and track
of embedded shortwaves pivoting within the mean trough. Models
suggest the first of these waves swings through the region Tuesday
night into Wednesday. Precipitation amounts do not look terribly
impressive but at this point, anything will help. There is lower
confidence regarding the track and time of the next slug of energy
so will trend pops toward climatology which mainly mentions a
chance of showers in the mountains. With the cooler trough aloft,
afternoon instability may be sufficient in generating light
showers each afternoon. As for thunder, the main threat looks to
be in the higher terrain near the International Border Wednesday
afternoon and early evening. As for winds...breezy conditions are
possible each afternoon but the main periods we will emphasis
given the wildfires in the region will be Wednesday and Friday. A
cold front on Wednesday will bring a moderate push of winds with a
majority of the Basin looking at sustained winds from 15 to 25 and
gusts toward 35 mph. Similar winds could be experienced on ridge
tops. These winds will be from the southwest. On Friday, a cold
front drops in from the north bringing a northerly push of winds
through the region. The narrow and N-S oriented valleys of
Okanogan Valley and Purcell Trench will receive the brunt of this
wind but northerly winds can be anticipated region-wide. Speeds
have been increased between 10-15 mph with this forecast package
and may need to come up further. Stay tuned. /sb

&&

.AVIATION...
00Z TAFS: Scattered showers and isolated thunderstorms will
affect extreme northeast WA and the northern panhandle of ID
behind a cold front moving into western Montana. Breezy west to
southwest winds will diminish after 03Z. Low level moisture from
recent rainfall and light upslope flow may allow MVFR ceilings in
low stratus to form between around 10Z to 16Z...affecting
KGEG/KSFF/KCOE. KPUW could also see MVFR conditions but
confidence is low. /EK

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        50  72  53  75  54  68 /  20  20  20  10  10  30
Coeur d`Alene  48  71  51  74  52  67 /  30  20  20  10  20  40
Pullman        48  73  48  76  51  68 /  20  10  10  10  20  30
Lewiston       53  81  56  83  58  74 /  10  10  10  10  10  30
Colville       48  68  49  73  50  69 /  20  30  30  20  30  40
Sandpoint      47  69  48  72  50  66 /  30  30  20  20  30  50
Kellogg        45  70  47  73  50  65 /  40  20  10  10  40  50
Moses Lake     52  77  54  77  53  72 /  10  10  10  10  10  10
Wenatchee      53  74  54  74  54  71 /  10  20  10  10  10  10
Omak           50  72  50  74  48  71 /  10  30  20  10  20  20

&&

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

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.