A persistent ridge of high pressure resulted in major to extreme heat risk in the lower Salmon and lower Clearwater River valleys.
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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 MSO wrote it up.
A persistent ridge of high pressure resulted in major to extreme heat risk in the lower Salmon and lower Clearwater River valleys.
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 Missoula, MT wrote its last area forecast discussion before the first event at Aug 1, 1:23 AM PST, 9 hours 37 minutes earlier.
Area Forecast Discussion
National Weather Service Missoula MT
323 AM MDT Thu Aug 1 2024
.DISCUSSION...A ridge of high pressure centered over the Great
Basin will begin to amplify over the Northern Rockies and reach
peak strength by the end of this week. The results will be the
return of hot and dry conditions across the region. By Friday,
high temperatures will rise significantly, with central Idaho's
low valleys expected to reach 100-115 F, and western Montana's
valleys forecast to experience highs in the 90s to low 100s. Due
to the expected excessive heat, an Excessive Heat Warning is in
effect for the lower valleys of western Idaho and Clearwater
counties in Idaho, along with heat advisories along the ID/MT
border. Widespread haze and smoke is also forecast to return
beginning Friday as southwesterly flow sets up.
Monsoon moisture is expected to arrive this weekend from the
southwestern U.S. The timing for the main influx continues to be
Saturday night into Sunday. With the heat on Saturday, any
thunderstorms that develop could produce gusty winds. By later Saturday
night into Sunday, storms will have plenty of atmospheric
moisture to work with (over 200% of normal) and could produce
periods of heavy rain. Lightning may also lead to new fire starts.
Next week looks to be unsettled as there could be showers and
thunderstorm chances each day. Between Tuesday and Wednesday,
there is a 60% chance that combined wind shear and instability
could support strong thunderstorms across northwest Montana. Also
another interesting thing to note will be the unseasonably cool
pattern east of the Divide by mid to late week. This cooler air
could infiltrate areas just west of the Divide into western
Montana at times along with easterly breezes. There is a 50 to 70%
probability that highs may only be in the 70s in these areas by
Friday, while the remainder of the region could be in the 80s and
90s in the lower valley of Idaho.
&&
.AVIATION...Patchy fog is possible this morning across northwest
Montana. Otherwise, mostly clear skies and warm temperatures are
expected today with high pressure building into the Northern
Rockies.
&&
.CLIMATE...Preliminary July 2024 climate stats are as
follows...Kalispell Montana saw its 6th warmest July tied with
1920, Missoula was the 9th warmest tied with 2023, and 2022; Butte
saw its 8th driest with only 0.19 of an inch; Salmon Idaho saw
its 6th warmest July tied with 1988 and ended up being the 9th
driest with only 0.17"; and Pierce Idaho saw its 10th warmest
July.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT... Heat Advisory from noon Friday to 9 PM MDT Saturday for
Kootenai/Cabinet Region...Lower Clark Fork Region.
ID...Heat Advisory from noon today to 8 PM PDT Saturday for Northern
Clearwater Mountains...Southern Clearwater Mountains.
Excessive Heat Warning from noon today to 8 PM PDT Saturday for
Lower Hells Canyon/Salmon River Region...
Orofino/Grangeville Region.
&&The national radar mosaic for the moment the first event began.
2 heat. Local standard time, as filed.
A strong ridge of high pressure resulted in Excessive Heat Watches and Warnings. The Heat Risk was rated Major to Extreme. An observing site in Orofino, ID reached a high of 104 degrees on August 1.
A strong ridge of high pressure resulted in Excessive Heat Watches and Warnings. The Heat Risk was rated Major to Extreme. A RAWS observing site in Slate Creek, ID reached a high of 113 degrees on August 2 with low temperatures only getting down to about 78 degrees.
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, August 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: 1201829, 1201830.