Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 301200
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
500 AM PDT Fri Sep 30 2016

.SYNOPSIS...
There`s an increased chance of showers and thunderstorms
overnight tonight. Noticeable cooling will begin on Friday with a
another chance of showers Friday night into Saturday morning. A
strong pattern shift to much cooler and unsettled conditions will
begin this weekend and continue into next week.

&&

.DISCUSSION...
Today through Saturday: Deep southerly flow will be common with
one minor embedded wave this morning, then a strong short-wave
trough/vort max Saturday. The current thunder across Ern Wa and N
Idaho is expected to decrease and move northeast... following a
plume of convective instability aloft in the moist southerly flow.
For Saturday, we`ll see the wave that`s now digging into the base
of the offshore trough lift into the Cascades/Columbia Basin and
produce another round of pcpn. Fcst soundings show a marginal
thunder threat with this vort max Saturday...especially if the steep
mid- level lapse rates aloft can couple with some sfc heating
within breaks in the clouds.bz

Saturday night through Wednesday...It still looks like the closed
low that will bring precipitation to the region Friday and
Saturday will take a southern track along the Oregon coast then
inland through southern Oregon and northern California Sunday
through early Monday. Weak high pressure will build into the
region late in the day on Monday, but that will be short lived as
another Pacific weather system will move into the region on
Tuesday, with yet another poised off the B.C. coast through
Wednesday. Quite a progressive pattern to be sure.

Saturday night through Monday...Showers will linger along the
crest of the Cascades Saturday evening as the closed low stays
off the coast. Then we can expect drier conditions Sunday and
Monday as the best moisture and dynamics stay well south of the
area. More sunshine will allow a couple of degrees of warming both
Sunday and Monday. But temperatures will remain on the cool side
of normal.

Tuesday and Wednesday...A return to a more active pattern is
expected Tuesday and Wednesday. Another low pressure system will
drop out of the Gulf of Alaska and take up position off the B.C.
coast. A fairly robust disturbance will move through the region
during the day Tuesday and bring another round of showers to the
the area. While the best chances will remain for the higher
terrain, just about all areas could see showers through sunset. By
Wednesday confidence in the forecast drops off precipitously as
guidance is really all over the place. For now the forecast will
hang onto mountain showers for Wednesday afternoon. We also expect
temperatures once again to cool below normal. Tobin

Thursday and Friday: Confidence is low during this period as
models are very noisy with the placement and timing of
disturbances which would bring rain to the region. The general
consensus is for a continued progressive fall-like pattern with
cool temperatures and periodic rain chances (outside of the deep
basin and just east of the Cascades). It is too far out to
confidently say when these waves will move through but in general
the cool and unsettled weather continues. /bwilliams

&&

.AVIATION...
12Z TAFS: Narrow bands of showers and isolated thunderstorms
moving south to north can be expected much of the
morning...followed by a brief break in the pcpn threat. Another
round of showers and isolated thunder is expected for 21z/Fri to
02z/Sat for all but the KMWH and KEAT area. More widespread pcpn
is expected Sat morning, though ceilings should remain VFR.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        72  46  61  42  65  42 /  30  70  20  10  10  10
Coeur d`Alene  72  47  60  42  65  41 /  40  70  40  10  10  10
Pullman        73  43  60  39  66  37 /  40  60  20  10  10  10
Lewiston       78  51  67  45  71  46 /  20  40  30  10  10  10
Colville       73  43  64  37  66  38 /  30  70  30  10  10   0
Sandpoint      70  43  59  36  62  37 /  60  80  60  10  10  10
Kellogg        72  44  56  38  62  39 /  40  60  60  10  10  10
Moses Lake     75  41  67  40  69  41 /  20  20  20  10  10   0
Wenatchee      73  46  66  43  67  46 /  10  10  30  10  10  10
Omak           74  43  66  40  67  42 /  10  10  40  10  10  10

&&

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

$$



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