A Dust Storm from the Washington Columbia Basin impacted extreme western edge of the Low Idaho Panhandle. It was driven by the passage of a dry cold front during the afternoon of September 29.
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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.
A Dust Storm from the Washington Columbia Basin impacted extreme western edge of the Low Idaho Panhandle. It was driven by the passage of a dry cold front during the afternoon of September 29. Wind gusts ranged from 35 to 42 MPH in the area. The impact was reduced visibility to less a quarter of a mile along Highway 95 near Tensed.
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 Sep 29, 9:59 AM PST, 3 hours 1 minute earlier.
Area Forecast Discussion
National Weather Service Spokane WA
1059 AM PDT Sun Sep 29 2024
.SYNOPSIS...
A strong cold front will push through the area this morning,
bringing gusty winds through this afternoon. These winds will
result in blowing dust and critical fire weather conditions across
much of the Inland Northwest. Temperatures will be very chilly
Monday morning with frost and freeze conditions. Another cold
front on Tuesday will bring breezy winds Tuesday afternoon through
Wednesday.
&&
.DISCUSSION...
Sunday: Today is shaping up to be an impactful late morning and
afternoon with critical fire weather conditions and blowing dust
the primary concerns. Water vapor and nighttime satellite
products showing a band of clouds and light showers associated
with a mostly dry cold front moving through central Washington as
of 2 AM PDT. A trailing upper level trough moving across southern
British Columbia will support showers post frontal showers across
north Idaho this afternoon.
* FIRE WEATHER: In response to the rising pressure behind the
front, a +8.7 mb pressure gradient between SEA and EAT is
bringing breezy winds through the Cascade gaps early this
morning. As the front pushes through eastern Washington and
north Idaho this morning, efficient boundary layer mixing and a
tight pressure gradient will support windy conditions across
much of the region with sustained winds 20 to 30 mph and wind
gusts up to 45 mph. Extremely dry air behind the front will
allow precipitable water values to plummet with relative
humidity values dropping into the upper teens and low 20s.
Despite the cooler temperatures this afternoon, the strong winds
combined with the very dry conditions will result in a rapid
spread of any new wildfires.
* DUST: These winds will also be capable of lofting dust across the
Waterville Plateau, Columbia Basin, Palouse, and Spokane area
near recently worked fields. Very little rain over the last
couple months combined with peak planting season in these areas
will support visibilities between 2 to 5 miles and localized
visibilities down to 1 mile will be possible later this morning
through the early evening. Use caution while traveling today. If
you encounter dense dust while traveling, pull off the road as
far as you can, turn off your lights, put your car in park, and
set your emergency brake.
Monday and Tuesday: Winds will become calm Sunday night into
Monday morning. Strong radiative cooling will result in a very
chilly Monday morning. There is a high probability (90 to 100
percent chance) for temperatures below freezing Monday morning for
locations within the northeast Washington and north Idaho
valleys. Places in the Washington and Idaho Palouse will see
temperatures near freezing with a 30 to 60 percent chance to drop
below freezing.
The flow aloft becomes more zonal by Tuesday as a low pressure
system nears the northern British Columbia coast and weak upper
level ridging amplifies from the south. Modest warming will be felt
across the Inland Northwest for Tuesday although the northern
valleys will dip to near freezing early in the morning. Winds will
become breezy Tuesday afternoon from the south-southwest ahead of
the front with wind gusts up to 20 to 30 mph in the afternoon. /vmt
Wednesday through Saturday: Shortwave ridging will once again be
suppressed by a weather system moving across southwest Canada and
dipping into the Northwest corner of the States midweek. This
midweek weather disturbance will bring another reinforcing shot of
breezy and dry conditions as well as keeping temperatures right
around seasonal normal for early October (mid 60s during the
day/low to mid 40s overnight). The dry conditions will continue
into the weekend when the next chance for moisture arrives.
* Wind & Dry: Precipitable water readings in the 40% of normal
range and surface dew points back in the 20-30F range will
once again produce elevated concerns for fire weather on
Wednesday. Differences among the National Blend of Models and
the low- resolution global ensembles vary for wind speeds on
Wednesday (see below). PWAT values will slowly climb above
50-60% of normal by next weekend with another shortwave feature
moving through the region.
- NBM: 40-60% probability of winds 15+ mph Wednesday.
- Other ensembles (ECMWF, GFS): 10-15% probability of winds 15+
mph Wednesday.
* Uncertainty: The ensemble cluster of models from WPC has almost
an equal split of 30/30/30 percent for the solution of where
the weather system will align for Wednesday with none of these
options showing a strong difference in placement. The varying
probabilities in wind speed would indicate uncertain placement
of the upper level and surface conditions.
* Impacts: Another round of dry and breezy conditions Wednesday
will keep the near critical fire weather conditions at the
forefront of the messaging. As winds relax and moisture values
rise later in the week, this concern will decrease. Temperatures
will be on the cooler side, but the wind and dry conditions
will be of concern for any new fire starts or fire spread.
/Dewey
&&
.AVIATION...
18Z TAFS: Gusty winds will continue across eastern Washington and
north Idaho through the afternoon. Local gusts of 35 to 45 mph
will lead to visibility reductions due to blowing dust, with the
best chances at KEPH and KMWH. Slight chances for showers in
extreme northeast WA and north ID through 00Z Monday. Winds
decrease after 03-06Z Monday.
FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate
confidence in visibility reductions in blowing dust this
afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 34 63 39 71 45 / 0 0 0 0 0 0
Coeur d'Alene 63 34 63 38 70 45 / 10 0 0 0 0 0
Pullman 60 32 61 36 70 46 / 10 0 0 0 0 0
Lewiston 70 41 68 43 78 54 / 10 0 0 0 0 0
Colville 65 26 64 31 69 31 / 0 0 0 0 0 0
Sandpoint 63 32 61 35 66 40 / 20 0 0 0 0 10
Kellogg 59 37 59 42 68 48 / 10 0 0 0 0 0
Moses Lake 66 33 65 38 73 44 / 0 0 0 0 0 0
Wenatchee 62 41 65 46 76 49 / 0 0 0 0 0 0
Omak 68 36 68 43 72 43 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning from 11 AM this morning to 7 PM PDT this
evening for Northern and Central Idaho Panhandle (Zone 101).
Freeze Warning from 1 AM to 8 AM PDT Monday for Central
Panhandle Mountains-Idaho Palouse-Northern Panhandle.
Frost Advisory from 1 AM to 8 AM PDT Monday for Coeur d'Alene
Area-Lewis and Southern Nez Perce Counties.
WA...Red Flag Warning from 11 AM this morning to 7 PM PDT this
evening for Colville Reservation (Zone 702)-Eastern
Columbia Basin -Palouse -Spokane Area (Zone 708)-
Foothills of Northeast Washington (Zone 701)-Lower Palouse
-Snake River (Zone 709)-Okanogan Valley (Zone 703)-
Waterville Plateau (Zone 706)-Western Columbia Basin (Zone
707).
Freeze Warning from 1 AM to 8 AM PDT Monday for Northeast
Mountains-Okanogan Highlands-Washington Palouse.
Frost Advisory from 1 AM to 8 AM PDT Monday for Moses Lake Area-
Okanogan Valley-Spokane Area-Upper Columbia Basin-
Waterville Plateau.
Blowing Dust Advisory from 9 AM this morning to 7 PM PDT this
evening for Moses Lake Area-Spokane Area-Upper Columbia
Basin-Washington Palouse-Waterville Plateau.
&&The national radar mosaic for the moment the first event began.
1 dust storm. Local standard time, as filed.
Public reported through social media that blowing dust reduced visibility less than a quarter mile on US 95 northbound 1 mile southeast of Tensed, Idaho.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2024Every state in 2024This day in weather historyWarnings in Idaho, September 2024
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: 1219009.