An active cold front moving through the Northern Rockies produced strong to severe winds across parts of South Central Idaho.
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 BOI wrote it up.
An active cold front moving through the Northern Rockies produced strong to severe winds across parts of South Central Idaho.
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 Boise, ID wrote its last area forecast discussion before the first event at Sep 7, 1:55 PM MST, 5 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service Boise ID
255 PM MDT Mon Sep 7 2020
.SHORT TERM...Tonight through Wednesday night...A strong cold
front will continue to progress south across the region this
afternoon and evening. The strongest winds are expected to peak
in the late afternoon/early evening, reaching 60 mph gusts between
Mountain Home and southern Twin Falls county and up to 50 mph
gusts elsewhere. Winds will kick up blowing dust, reducing
visibilities in open areas. Strong winds are also expected to blow
debris and tree limbs, potentially resulting in power outages and
property damage. Strong winds pose dangerous fire conditions,
causing any fire starts to spread rapidly. The High Wind Warning
and Wind Advisory have both been extended through 11 PM MDT, as
models are showing stronger winds lasting longer into the evening,
especially over southern Malheur County and the Owyhees. Winds
will decrease late in the evening, shifting mostly northeasterly
overnight. Showers are moving over the West Central Idaho
Mountains this afternoon and may track south into the Magic Valley
this evening. Snow levels will lower to 3800-4500 ft MSL late
tonight behind the cold front, with little to no snow accumulation
expected. Tuesday will feature much cooler temperatures, roughly
20 degrees lower than today. Winds on Tuesday will be much lighter
than today, peaking around 10-20 mph. Northeast flow aloft will
continue into Wednesday as the upper low tracks to the southeast
and a ridge builds off the Pacific Northwest coast. Temperatures
on Wednesday will increase several degrees but remain nearly 10
degrees below normal.
.LONG TERM...Thursday through Monday...The weekend will see
northwest flow aloft as an upper low progresses to the east. A
system will approach the Pacific coast at the tail end of the
weekend, causing ridging aloft. Temperatures on Thursday will
start several degrees below normal, and each day will gradually
warm a couple degrees to become 5-10 degrees above normal by next
Monday. Conditions will stay dry through the period.
&&
.AVIATION...Mostly VFR. Blowing dust will cause localized MVFR to
IFR visibilities this afternoon as the cold front passes. Surface
winds: west to northwest 25-40 kts with local gusts to around 50
kts following the cold front. Winds aloft near 10k feet MSL:
northwest 30-40 kts, turning northeast behind the cold front.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...High Wind Warning until midnight MDT tonight IDZ014>016-030.
Red Flag Warning until 9 PM MDT this evening IDZ420-423-424-426.
Wind Advisory until midnight MDT tonight IDZ012-013-028-029.
OR...Red Flag Warning until 9 PM MDT /8 PM PDT/ this evening
ORZ636-637.
Wind Advisory until midnight MDT /11 PM PDT/ tonight ORZ062>064.
&&
www.weather.gov/Boise
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SHORT TERM...AL
LONG TERM....AL
AVIATION.....ALThe national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The Jerome ASOS measured a wind gust of 64 MPH in conjunction with cold frontal passage. Trained spotters also reported wind damage around the Buhl area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2020Every state in 2020This day in weather historyWarnings in Idaho, September 2020
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: 922083.