A closed upper low over the Great Basin and vicinity shifted northeastward toward the region while it spawned a surface low across eastern MT. As the upper level disturbance and surface low became stacked across eastern MT, a period of widespread heavy rain developed where the TROWAL set up across the eastern plains.
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 TFX wrote it up.
A closed upper low over the Great Basin and vicinity shifted northeastward toward the region while it spawned a surface low across eastern MT. As the upper level disturbance and surface low became stacked across eastern MT, a period of widespread heavy rain developed where the TROWAL set up across the eastern plains. Additionally, a few strong northwesterly gusts were observed on the west side of the surface low. Overall, the soil was quite dry before the onset of the event, which allowed for heavy rain to be largely beneficial.
Rain amounts from this event were greatest across the eastern plains (Fergus, Blaine, Hill, Chouteau, and Judith Basin counties), largely ranging between 2 and 5 inches, with a few reports of upwards of 7 and a half inches. Areas that reported rain in excess of 6 inches include 10 S of Chinook in Blaine county (7.42), 5 NE Hilger in Fergus county (7.25), 2 S Chinook in Blaine county (6.6), and 7 SE Lewistown in Fergus county (6.5). ASOS station KLWT Lewistown Airport measured 4.35 over 24 hours during the calendar day of September 18 (Standard time), which was the second highest single day precipitation total on record in the Lewistown climate records.
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 Great Falls, MT wrote its last area forecast discussion before the first event at Sep 17, 1:19 PM MST, 21 hours 41 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
1 flood, 1 high wind. Local standard time, as filed.
Broadcast media reported minor flooding at the Blaine county fairgrounds. Standing water upwards of 6 inches in spots was reported.
RAWS station JPKM8 Judith Peak measured two gusts in excess of 60 mph, including a peak gust of 67 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2024Every state in 2024This day in weather historyWarnings in Montana, 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 2026-10-01. Each event’s entry at NCEI: 1207238, 1207231.