953
FXUS66 KOTX 152207
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
307 PM PDT Sun Sep 15 2024

.SYNOPSIS...

Monday will be the warmest day of the week. Tuesday and Wednesday
will be cooler with periods of rain over north Idaho and the
eastern third of Washington. Gusty north winds down the Okanogan
valley Monday will become breezy from the west on Tuesday and be
more widespread across parts of central and eastern Washington.

&&

.DISCUSSION...

Tonight through Tuesday: Bands of light showers will continue to
pass over southeastern WA and the ID Panhandle tonight as a center
of low pressure rolls down the West Coast toward California. A few
showers will linger over the L-C Valley and Camas Prairie tomorrow,
but the rest of the region will remain dry with mostly clear skies
and temperatures several degrees warmer than today`s. Northerly
winds will pick up in the Okanogan Valley overnight tonight and into
tomorrow morning due to the pressure gradient created by the low to
our south. Winds will peak in the late morning tomorrow with gusts
up to 35 mph expected.

Blue skies and dry conditions will be short-lived with another low
on track to drop down the coastline from the Gulf of Alaska on
Tuesday, bringing temperatures back down into the upper 60s to low
70s and increasing chances for showers primarily over the Cascade
Crest, the eastern third of WA, and the ID Panhandle. /Fewkes

Wednesday through Sunday: We remain under the influence of a
trough on Wednesday with the energy well to our south. Thursday
onward there is the potential of a ridge setting up. There are
some fairly large discrepancies as to where the ridge sets up, if
at all. By Saturday the 100 member ensemble forecast is showing a
60/40 split of a ridge scenario vs a trough scenario. The ridge
scenario is quite different with 30% of it showing the ridge off
the coast, which creates more of a northwest flow for us and would
keep showers perhaps going for northeast WA and the ID Panhandle.
Another 30% shows the ridge further east over western WA which
would be drier scenario. The trough scenarios have it located off
the coast, they just disagree on the strength of the low.

So, what`s in the forecast? Well daytime temps will be in the mid
60s to mid 70s and lows in the 40s. Through Friday the forecast is
largely dry except for at the crest of the Cascades and parts of
the ID Panhandle. Saturday and Sunday the threat of showers
expands a bit to encompass most of the region, but the best chance
for rain will be across the Cascades, extreme eastern Washington
and the ID Panhandle. It looks like for the most part, central WA
will continue to remain dry. Winds will be light with gusts not
exceeding about 15 mph. /Nisbet

&&

.AVIATION...
18Z TAFS: VFR conditions will prevail for the TAF sites. Showers
will continue, mainly up around the Republic area. Around 20Z a
shower band will lift north around the PUW and LWS area, but
showers are expected to be light with little to no impact on
visibilities.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS:
Confidence remains high for VFR conditions at the TAF sites. Given
the narrow band of rain shown by the models over far Eastern WA/N
Idaho today, prevailing conditions could develop into a steady
light rain for a couple hours locally.

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        52  78  48  71  48  73 /  10  10   0  20  10  10
Coeur d`Alene  49  78  50  67  49  69 /  10  10  10  40  30  30
Pullman        44  74  49  65  45  67 /  10  20  20  50  20  20
Lewiston       51  78  55  71  55  74 /  20  20  30  50  30  10
Colville       47  81  47  76  38  74 /  10   0   0  10  10  10
Sandpoint      49  76  48  68  46  66 /  10  10  10  50  40  30
Kellogg        49  74  50  65  51  62 /  10  20  20  70  50  50
Moses Lake     49  81  50  78  48  76 /  10   0   0   0   0   0
Wenatchee      54  81  56  76  56  76 /   0   0   0   0  10   0
Omak           54  82  48  81  51  80 /   0   0   0   0   0   0

&&

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

$$