Wildfire started from unknown cause on July 20.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS OTX wrote it up.
Wildfire started from unknown cause on July 20.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Spokane, WA wrote its last area forecast discussion before the first event at Jul 20, 1:30 AM PST, 1 hour 56 minutes earlier.
Area Forecast Discussion
National Weather Service Spokane WA
230 AM PDT Thu Jul 20 2023
.SYNOPSIS...
Thursday and Friday will feature hot temperatures and clear
skies. A heat advisory is in effect from noon Thursday through
Friday evening for the Lewiston Area and the Lower Garfield and
Asotin Counties which is likely to experience triple digit heat.
Saturday will begin a cooling trend which continues through the
middle of next week. Winds will also become breezy to gusty each
day with the strongest winds expected on Monday.
&&
.DISCUSSION...
Today through Wednesday:
Temperatures: A strong H5 ridge continues to hold over the CWA and
will strengthen through the rest of the work week. As the ridge
strengthens and subsidence grows stronger, temperatures are
progged to warm roughly 10 degrees from Wednesday’s highs. Highs
are expected to be in the upper 90s in most of the area, with some
spots hitting the lower 100s. Lows will struggle to drop below
the mid 60s. The lack of nighttime relief and high daytime
temperatures have led to a heat advisory being issued for the
Lewiston Area and the Lower Garfield and Asotin Counties. The heat
advisory will be active from noon Thursday until 8pm Friday.
As we get into the weekend, an offshore trough will be moving in and
pushing the ridge to our east. As this happens, a subtle cooling
trend is expected with highs dropping to the low 90s Saturday and
Sunday. Monday and Tuesday the area will lower further into the
mid 80s as the trough continues to migrate into the area.
Winds: The pressure gradient will tighten further late week into the
weekend, leading to gusty gap flows on Friday and Saturday. Early
next week, the pressure gradient will widen and gusty winds will
spread across most of eastern Washington and the ID Panhandle.
Probabilities of sustained winds at or slightly stronger than 15
mph vary from 40-60% for the Cascade Gaps, Waterville Plateau, and
southern Okanogan Valley starting Friday and continuing through
Sunday. These percentages continue to increase > 60% for Monday as
the air mass continues to cool. Wind gusts around 25 mph will
likely accompany these sustained speeds. Along with the gusts, RH
values are expected to drop into the teens to low 20s throughout
the period. This combined with the dry fuels from the current heat
will lead to elevated fire weather conditions with local areas
flirting with red flag conditions for a few hours each afternoon-
early evening. Monday does carry the greatest risk for widespread
gusty winds but speeds do not appear as strong as this previous
red flag event due to a more subtle cooling leading up to the
event.
On Tuesday, some deterministic models are showing a shortwave
moving over us from the Southwest, along with moisture advection
bringing PWATs to 140-150% of normal combined with strong daytime
heating. This could be enough to spark some thunderstorms over the
higher elevations in Northern WA and the ID Panhandle; this comes
with low confidence (<15%) due to differences within the models.
Wednesday features additional model uncertainty in the positioning on
the next ridge or trough over our area. Clusters are nearly
evenly split between the Northwest being under an H5 ridge or
staying under the trough. The former has 54 members, while the
latter has 46 members. This leads to moderate uncertainty with the
forecast and larger spread in the guidance for temperatures and
winds. The summer weather pattern still looks void of any
significant precipitation. /Sinowitz/Bodnar
&&
.AVIATION...
12z TAFs: Winds are expected to stay light for the next 24 hours,
skies should be clear as high pressure dominates. A few cumulus
buildups are expected over the Pasayten Wilderness with a 10%
chance or less for a stray thunderstorm. Smoke drifting in from
the Canadian wildfires will bring hazy skies to North Idaho and
portions of Northeastern WA yet visibilities should remain above
6SM. /Sinowitz/Bodnar
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 97 63 98 63 94 60 / 0 0 0 0 0 0
Coeur d'Alene 96 62 96 61 93 59 / 0 0 0 0 0 0
Pullman 96 59 95 58 90 56 / 0 0 0 0 0 0
Lewiston 104 70 104 69 101 67 / 0 0 0 0 0 0
Colville 96 56 96 55 93 52 / 0 0 0 0 0 0
Sandpoint 92 58 94 57 91 56 / 0 0 0 0 0 0
Kellogg 92 67 94 66 90 64 / 0 0 0 0 0 0
Moses Lake 102 63 100 60 97 58 / 0 0 0 0 0 0
Wenatchee 100 69 98 66 94 64 / 0 0 0 0 0 0
Omak 101 67 101 63 98 61 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory from noon today to 8 PM PDT Friday for Lewiston
Area.
WA...Heat Advisory from noon today to 8 PM PDT Friday for Lower
Garfield and Asotin Counties.
&&The national radar mosaic for the moment the first event began.
1 wildfire. Local standard time, as filed.
The fire started on July 20 from unknown cause and was contained on July 21. It burned 473 acres of grass and brush. No structures lost.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2023Every state in 2023This day in weather historyWarnings in Washington, July 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1127096.