040
FXUS66 KOTX 210500
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1000 PM PDT Sat Jul 20 2024

.SYNOPSIS...
Very hot temperatures will continue through Monday with widespread
triple digit heat Sunday and Monday. A significant pattern change
will arrive on Tuesday with the arrival of a dry cold front.
Temperatures will cool to near average values by Thursday. Breezy
winds and dry conditions each afternoon will result in elevated
fire weather concerns.

&&

.DISCUSSION...

Today through Sunday Night: Excessive heat continues to be of
major concern, as temperatures will continue to increase past
already dangerous levels and place much of the area at extreme
risk. Models and observations continue to show a strong upper-
level ridge building into the area today and remaining strong on
Sunday. The ridge axis has stalled over the area but will begin to
shift east on Monday. Initial warming will be due to subsidence
from the ridge, but upper-level flow will become southerly on the
back side of the ridge as it shifts east, with 850mb temperatures
forecast to reach as high as 32C on Sunday. This is associated
with surface high temperatures in the upper 90s to around 110
degrees. Excessive Heat Warnings are in effect until 8 PM PDT
Monday. Vulnerable populations should plan to find cooling, and
animals should be brought indoors if possible or given water,
shade, and fans otherwise.

Monday through Saturday: On Monday, the upper low will continue
to strengthen in the Gulf of Alaska and reach farther south and
east, bringing southwesterly flow. An associated 500mb trough will
begin to influence the area Monday and allow the ridge to begin
to break down. This will bring lower surface temperatures (upper
80s and lower 90s) but increasing wind, especially in central WA.
Increasing winds ahead of a dry cold front in combination with
extremely dry air will be of concern for any existing fires.
Forecast CAPE ahead of the front on Monday is around 500-1000 J/kg
in northeast Washington and north Idaho. Positive vorticity
advection (lift) and elevated moisture raises concern for high-
based thunderstorms capable of dry lightning Monday.

Models indicate dry and breezy conditions will continue through
next week despite cooler temperatures Tuesday onward, with high
temperatures in the mid 80s to mid 90s, with pockets approaching
the low 100s in the L-C valley. Increased surface winds in
combination with continued extremely dry air will create multiple
days of elevated to critical fire weather conditions, particularly
Thursday. The fire threat will be closely monitored in the coming
days. Another potential warmup looms into August with the
ensembles showing broad ridging potentially returning at the end
of July. /Cooke /Butler

&&

.AVIATION...
06Z TAFS: An upper level ridge will allow VFR conditions to
continue through the period. The only exception will be some hazy
conditions from smoke near wildfires that may reduce visibilities.
Breezy easterly winds will pick up in the Basin tomorrow
afternoon.

FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: With the
exception of smoke near wildfires confidence is high for continued
VFR conditions.

-----------------------

Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70
percent chance
High - Greater than a 70 percent chance

For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https:/www.weather.gov/otx/avndashboard

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        67 105  70 100  63  93 /   0   0   0   0   0   0
Coeur d`Alene  67 103  68  99  62  89 /   0   0   0   0   0   0
Pullman        58 102  59  95  57  89 /   0   0   0   0   0   0
Lewiston       73 111  75 106  69  98 /   0   0   0   0   0   0
Colville       57 103  60  99  55  92 /   0   0   0   0   0   0
Sandpoint      62  99  64  98  58  88 /   0   0   0   0   0   0
Kellogg        72  99  73  98  66  90 /   0   0   0   0   0   0
Moses Lake     64 108  68 102  58  95 /   0   0  10   0   0   0
Wenatchee      74 106  74 102  64  95 /   0   0  10   0   0   0
Omak           68 109  73 107  64  97 /   0   0  10   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Excessive Heat Warning until 8 PM PDT Monday for Central
     Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis
     and Southern Nez Perce Counties-Lewiston Area-Northern
     Panhandle.

WA...Excessive Heat Warning until 8 PM PDT Monday for Central Chelan
     County-Lower Garfield and Asotin Counties-Moses Lake Area-
     Northeast Blue Mountains-Northeast Mountains-Okanogan
     Highlands-Okanogan Valley-Spokane Area-Upper Columbia Basin-
     Washington Palouse-Waterville Plateau-Wenatchee Area-
     Western Okanogan County.

     Red Flag Warning from noon to 10 PM PDT Sunday for East Portion
     of North Cascades National Park/Lake Chelan National
     Recreation Area (Zone 697)-East Washington Central Cascades
     (Zone 696)-East Washington North Cascades (Zone 698)-
     Foothills of Central Washington Cascades (Zone 705)-Methow
     Valley (Zone 704).

     Heat Advisory until 8 PM PDT Monday for Western Chelan County.

&&

$$