Wildfire in Washington, July 19 to 31, 2024

Area Forecast Discussion
National Weather Service Spokane WA
215 PM PDT Fri Jul 19 2024

.SYNOPSIS...

Strong high pressure will continue to amplify, bringing
increasing heat that will peak on Sunday, with widespread
temperatures in the 100s and some areas reaching 110 or higher. A
weather system will bring lower temperatures beginning next
Tuesday, but will also bring increased winds, which, combined with
dry weather, will bring increased fire risk.

.DISCUSSION…

Today through Sunday Night: Excessive heat continues to b e of
major concern, as temperatures will continue to increase past
already dangerous levels. Models are in good agreement that a
strong upper-level ridge will build into the area on Saturday and
remain potent on Sunday, with the ridge axis stalled over the area
during the weekend before slowly beginning to shift east into
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. The HRRR does show smoke from
Oregon drifting northward, which could abate temperatures
slightly, but with little-to-no forecast cloud cover through the
weekend, surface heating will be extreme. Heat Advisories are
currently in effect through 11 am PDT Saturday, with Excessive
Heat Warnings in effect from 11 am PDT Saturday through 8 PM PDT
Monday. Vulnerable populations should plan well in advance to find
cooling, and animals should be brought indoors if possible or
given water, shade, and fans otherwise.

Monday through Thursday: On Monday, the 300mb low will continue
to strengthen in the Gulf of Alaska and reach farther south,
bringing west-to-southwest flow that will bring an embedded
shortwave into the region and allow the ridge to begin to break
down, bringing a bit lower surface temperatures but increasing
wind, especially central WA. Increasing winds in combination with
extremely dry air will be of concern for any existing fires.
Forecast CAPE (100-200 J/kg), positive vorticity advection (lift),
200-850mb shear, 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 upper 80s to mid 90s. Increased surface winds
in combination with continued extremely dry air will create
multiple days of elevated to critical fire weather conditions,
which will be closely monitored in the coming days. /Cooke

&&

.AVIATION...
18Z TAFS: A building 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 along Lake Chelan, and the Methow Valley.

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        64 101  67 106  70 102 /   0   0   0   0   0   0
Coeur d'Alene  62  99  66 103  69 102 /   0   0   0   0   0   0
Pullman        59  97  63 102  63  98 /   0   0   0   0   0   0
Lewiston       71 107  72 112  75 107 /   0   0   0   0   0   0
Colville       53  99  56 104  60 101 /   0   0   0   0   0   0
Sandpoint      57  96  62 101  64 100 /   0   0   0   0   0   0
Kellogg        68  97  71  99  73 101 /   0   0   0   0   0   0
Moses Lake     61 102  65 109  68 102 /   0   0   0   0  10  10
Wenatchee      69 102  74 107  75 103 /   0   0   0   0   0   0
Omak           64 104  68 110  74 108 /   0   0   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory until 11 AM PDT Saturday for Central Panhandle
     Mountains-Coeur d'Alene Area-Idaho Palouse-Lewis and
     Southern Nez Perce Counties-Lewiston Area-Northern
     Panhandle.

     Excessive Heat Warning from 11 AM Saturday to 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...Heat Advisory until 11 AM PDT Saturday 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.

     Excessive Heat Warning from 11 AM Saturday to 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.

     Fire Weather Watch from Sunday afternoon through Sunday evening
     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 from 11 AM Saturday to 8 PM PDT Monday for Western
     Chelan County.

&&