Area Forecast Discussion
Issued by NWS Spokane, WA

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935
FXUS66 KOTX 240104
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
604 PM PDT Tue Aug 23 2016

.SYNOPSIS...
Isolated showers and thunderstorms are possible in north Idaho
and extreme northeast Washington this evening. Winds will increase
out of the north to northeast overnight into Wednesday. This will
help move areas of smoke away from their sources and southward.
Expect a gradual warming trend with mostly dry conditions through
the work week. Another dry cold front should arrive by Saturday
with more breezy winds.

&&

.DISCUSSION...
Tonight through Thursday night: Mostly dry and mild weather will
continue with a few short term challenges.

Winds/Smoke: Winds will be the main issue for the next several days
especially dealing with where the smoke will go. Areas of smoke
still linger around the Spokane area and near area fires with the
north-northwest winds. The winds will shift to the northeast
tonight as a weak front moves down across north Idaho. Could see
gusts of 15 to 20 mph over north Idaho and the Okanogan Valley
early this evening and again by early Wednesday morning. An area
of high pressure will set up in western MT and keep easterly winds
across much of the region. This will push smoke from area fires to
the south and west of the source regions, so away from the Spokane
area and into the Columbia Basin, the Palouse and even Shoshone
county from a fire in the Bitteroots. This trend is seen in the
HRRR smoke models. The east to northeast winds look to persist
through Thursday night, keeping smoke trends fairly similar
through mid week barring any change in fire development and lack
of breezy winds.

Showers/Thunderstorms: There looks to be more low level instability
than yesterday and convection is developing just north of the
border from Bonners Ferry. Expect this activity to continue to
grow and track to the south-southeast through the remainder of the
afternoon and early evening hours. There is a small chance of
thunderstorms over north Idaho early this evening. The HRRR has
been fairly robust on this convection and showing development back
to the west across northeast Washington, more so than the NAM4km.
With any convection that does form over the Okanogan Highlands/NE
Washington and the current NW steering flow, there is small chance
that this would push convection into the Spokane/Coeur d`Alene
area early this evening. Not much in the way of precipitation is
expected as most of the activity would be high based, but winds
would be a concern with northerly and even gusty outflow winds
from the north are possible. This will continue to be monitored
this evening. Otherwise for Wednesday, there is another small
chance of afternoon to evening showers and thunderstorms for the
northeast Washington and panhandle mountains. A lesser chance
exists for Thursday.

Temperatures: Despite the passage of the weak front, temperatures
will gradually moderate Wednesday and into Thursday. Expect
temperatures reaching near seasonal daytime levels, meanwhile cold
pockets are possible overnight in sheltered areas. /rfox.

Friday through Tuesday...Offshore ridge retrogrades westward a
bit and away from the coast as a low pressure system drops down its
east edge. The low is still expected to be positioned over Southern
British Columbia Friday early on so sensible weather for Friday
remains the same with a generally sunny forecast. Saturday, however,
should see remarkably increased southwest wind along with increased
cloud cover and pops added in order to mention a chance of
precipitation near the British Columbia Border. Moisture remains
limited so pops will not be too high. The disturbance finishes
dragging a cold front through and allows for some weak shortwave
ridging to build into part of Washington Sunday but the longwave
pattern at about this point on favors a general persistent trof
lingering in place with nothing too substantial in the way of
disturbances with good dynamics and moisture passing through it.
Therefore the end result is a forecast that depicts Friday and/or
Saturday as the warmest days ahead of the cold front/trof passage
that allow for cooling and increased wind (especially on Saturday)
that diminishes going into Sunday and beyond. /Pelatti

&&

.AVIATION...
00Z TAFS: Scattered showers will drift southward through the north
Idaho Panhandle this evening. At this time, it looks as if the
convection will dissipate before reaching the Couer d`Alene or
Spokane airports. However, Bonners Ferry and Sandpoint will
experience showers capable of light to moderate rain...as well as
a handful of lightning strikes through 04z. As for the smoke...
fire activity today has decreased compared to the last couple of
days. There is not as much smoke in the "air shed" so the chance
for visibility restrictions tonight into Wednesday should be
less. A transition to a northeast transport wind may bring smoke
from Spokane and Lincoln counties toward the Moses Lake airport
Wed morning. /GKoch

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  79  56  82  54  83 /  20  10  10   0   0   0
Coeur d`Alene  52  78  52  81  50  81 /  20  10  10   0  10   0
Pullman        47  80  48  81  46  82 /   0  10  10   0   0   0
Lewiston       55  86  56  88  56  88 /   0   0   0   0   0   0
Colville       50  82  51  84  50  84 /  10  10  10  10  10  10
Sandpoint      50  76  50  78  48  78 /  20  10  10  10  10  10
Kellogg        49  74  49  77  48  77 /  20  10  10  10  10  10
Moses Lake     54  88  56  90  53  89 /   0   0   0   0   0   0
Wenatchee      60  86  60  88  59  89 /   0   0   0   0   0   0
Omak           58  87  58  88  57  90 /   0   0   0   0   0   0

&&

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

$$



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