Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 192345
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
345 PM PST Sun Nov 19 2017

.SYNOPSIS...
Rain and mountain snow will spread into the Inland Northwest this
evening and persist through the night. A series of storm systems
will produce several rounds of rain this week. Snow levels will be
quite high Tuesday, Wednesday, and Thursday allowing motorists to
travel over mountain passes on wet pavement. Snow levels will
begin to lower just as travelers are heading home late Saturday
and Sunday.

&&

.DISCUSSION...
Tonight thru Monday Night: Precipitation is already reaching the
north Cascades, but this won`t push east of the Cascade crest
until after sunset. Rain and mountain snow will sweep through the
area tonight and Monday.

Temperatures in the Methow Valley have warmed into the mid/upper
30s. The precipitation type there should still be snow, but
temperatures will be too warm to allow for much accumulation. Loup
Loup and Blewett Passes also won`t see too much snow. As the
front moves east, Republic and Sherman Pass could see a couple of
inches. But most of this will also fall this evening, so again I`m
not expecting any real impactful weather.

Precipitation will reach the MT/ID border around midnight. Lookout
Pass should get snow, but temperatures will be right around
freezing. By Monday morning, snow levels will rise to the pass
level, so I`m not expecting a major impact there. As such, I don`t
plan on issuing any highlights for these passes.

After the initial band of rain moves through the region tonight, a
secondary band will likely develop over southeast Washington. This
could bring an inch of rain or more to this area, including
Pullman/Moscow.  RJ

Tuesday through Sunday: Warm and wet weather is expected Tuesday
through Thursday and then cooler temperatures are expected Friday
through Sunday. A warm front will lift north Tuesday and spread
rain across the region. The atmospheric river will be more focused
towards the WA coast and southern BC, nevertheless precipitable
water values of over an inch will be seen across eastern WA and
north ID. Rain is expected Tuesday through Thursday, with snow
only at the highest peaks in the northern Cascades Tuesday
morning. Snow levels rise to above 8k ft by the afternoon.
Thursday night and Friday a cold front will move through the
region. Precipitation will end west to east through the night and
into the day on Friday. Snow levels will lower through this
period, but it would only be a brief period at best that has a
chance to see accumulating mountain snow before it shuts off.
Friday night and early Saturday will be our only dry period in the
7 day forecast. Then late Saturday afternoon through Sunday
another system moves through the region, though this one will
provide lighter precipitation amounts to the region, and possibly
shadow out the Columbia Basin more than the system earlier in the
week. Sat night into Sunday morning snow levels will lower enough
for the potential of valley snow across northern WA.

Temperatures: Tuesday temps will be about 4-8 degrees above
average. Then Wed and Thur as we remain in the deep southerly flow
valley temps bump up into the 50s, or 12-16 degrees above
average. Friday through Sunday temps lower into the 40s, but still
remain several degrees above average. The trends are similar with
overnight low temps...above average readings are expected.

Winds: Southwest winds 10-15 mph winds are expected Thursday
afternoon through Friday afternoon with gusts 20-25 mph across
portions of the Columbia Basin, Palouse and into the Spokane area.

Impacts: Road impacts will be minimal Tuesday through Thursday
given the very high snow levels. All precipitation across mountain
passes will be rain. However, given all this rain, we will see
rises on area rivers and creeks. They will need to be monitored
closely as we head towards Thursday and Friday. It isn`t until
late Saturday and Sunday, right when people start heading home
from the holiday that we start to see accumulating snow on the
mountains. The main area of concern will be the Cascades and
Sherman Pass. /Nisbet

&&

.AVIATION...
00Z TAFs: Precipitation will spread into the Inland NW this
evening, continuing as showers on Monday. KEAT and KMWH should
remain VFR with very little rain tonight. They may see some
showers during Monday but conditions should remain VFR. To the
east, the airports should stay MVFR tonight with the rain, but
then approach IFR cigs in the morning. Conditions should improve
in the afternoon. RJ


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        39  45  37  48  45  55 / 100  70  20 100 100  70
Coeur d`Alene  38  44  36  46  43  54 / 100  90  20 100 100  70
Pullman        40  46  40  50  47  58 / 100 100  30  90  90  70
Lewiston       45  52  43  54  48  61 /  70  90  20  80  90  50
Colville       35  45  33  42  38  50 /  90  10  10 100  90  70
Sandpoint      35  41  33  42  40  49 / 100  90  10  90 100  80
Kellogg        36  41  35  44  41  50 / 100 100  40  90 100  80
Moses Lake     41  50  36  47  41  56 /  90  10  10  90  80  50
Wenatchee      37  48  35  44  38  52 /  40  10  10  90  60  60
Omak           36  44  34  43  39  50 /  90  10  10  90  80  40

&&

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

&&

$$



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