Area Forecast Discussion
Issued by NWS Spokane, WA

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743
FXUS66 KOTX 202335
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
435 PM PDT Sun Aug 20 2017

.SYNOPSIS...
High clouds will clear overnight. Skies should be favorable for
viewing the eclipse Monday morning, however there may be some
smoke in the northern valleys. Tuesday and Wednesday will be quite
warm with afternoon temperatures in the upper 80s to upper 90s.
A vigorous cold front passage has the potential to produce
thunderstorms Wednesday night into Thursday, mainly over the
North Idaho Panhandle. This will be followed by gusty west winds
Thursday.

&&

.DISCUSSION...
Tonight through Tuesday Night: The upper level ridge is building
along the west coast this afternoon and will move inland Monday.
Temperatures will continue to warm...into the mid 80s to low 90s
Monday and 90s on Tuesday (the warmest day of the week). Temps top
out Tuesday about 10 degrees above average for this time of the
year. The ridge will then begin to shift east Tuesday night ahead
of the next weather system set to move into the Pacific Northwest.
Southwest winds around Spokane/Deer Park and Coeur d`Alene will
continue at around 10 mph with gusts 15-20 mph, but should subside
early this evening. Otherwise winds will remain light and under
10 mph.

*Eclipse: Sky conditions for the eclipse Monday morning are
 expected to be sunny to mostly sunny with some high cirrus across
 northern WA and ID. Winds will become light and
 variable...similar to what we would see at night. /Nisbet

Wednesday through Thursday night: Significant changes in the weather
occur. Primary issue of note would be the windy/gusty conditions
brought about by a large trof/cold front passage on Thursday which
will result in blowing dust in some parts of the Columbia Basin. In
addition there are is a mention of the potential for thunderstorms
with this transition, both ahead of the incoming trof with the
southwest flow bringing them up with a robust storm motion from
southwest to northeast at 20 mph Wednesday up from Oregon and over
the Blue Mountains, through the Washington and Oregon Palouse and
points to their south, and into the Idaho Central Panhandle
Mountains. Thunderstorm potential along with storm motion increases
Wednesday night into Thursday to southwest to northeast at 30 mph
ahead of the cold front. In addition the potential for thunderstorms
increases Wednesday night into Thursday for Extreme Eastern
Washington and North Idaho. The most substantial conditionally
unstable air left in the region in the wake of the cold front
passage remains to the north over British Columbia and another trof
extending from it brushes over locations not too far from the border
so some mention of thunderstorms remains near these northern
locations along with portions of North Idaho where the upslope
prevailing southwest flow could still provide the lift and triggers
for convection there. A benefit of the prevailing southwest winds
during this time interval is that they would not bring smoke in from
Southern British Columbia fires but could stir smoke around our area
and perhaps bring in some from Oregon.

Friday through Sunday: Ridging moves into the area allowing for a
warming and drying trend with a generally dry forecast. Winds should
be more diurnally driven and as such considerably lesser in
comparison to Thursday. /Pelatti

&&

.AVIATION...
00Z TAFS: Smoke will continue to impact northern WA and ID
valleys, but not the main TAF terminals. Bkn-ovc high clouds
are currently moving across the region and will be exiting
overnight.  During the eclipse (16-19Z), expect light variable
winds with a very high few-sct300 cloud deck. Winds will be light
for all terminals through 00z Tue. /sb


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        58  86  62  92  63  89 /   0   0   0   0   0  10
Coeur d`Alene  53  87  56  92  58  89 /   0   0   0   0   0  10
Pullman        52  87  55  92  57  89 /   0   0   0   0   0  10
Lewiston       59  93  63  99  66  93 /   0   0   0   0   0  20
Colville       51  88  53  92  54  91 /   0   0   0   0   0  10
Sandpoint      47  85  50  91  51  86 /   0   0   0   0   0  10
Kellogg        51  85  55  91  56  86 /   0   0   0   0   0  10
Moses Lake     56  91  57  95  59  93 /   0   0   0   0   0  10
Wenatchee      63  90  66  95  66  91 /   0   0   0   0   0  10
Omak           60  92  61  96  62  94 /   0   0   0   0   0  10

&&

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

$$



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