Below average rainfall in August allowed drought conditions to persist or intensify in northeast Montana.
Every event with a place to put it; 7 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 GGW wrote it up.
Below average rainfall in August allowed drought conditions to persist or intensify in northeast Montana.
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 Glasgow, MT wrote its last area forecast discussion before the first event at Aug 31, 2:08 PM MST, 9 hours 52 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 308 PM MDT Thu Aug 31 2023 .DISCUSSION... AFTERNOON UPDATE: Smoke and haze is starting to filter in from Alberta/Saskatchewan with slight reductions in visibility (<10 mi) already being observed along the hi-line. Based on the latest run of the RAP near- surface smoke, this smoke is expected to filter further south as the day progresses, covering most of northeastern Montana by midnight tonight. The worst of the smoke is expected tomorrow morning in the 6 AM to 12 PM timeframe. Reductions to air quality as low as unhealthy levels, as well as reductions in visibility down to 4 miles are possible during this time. Otherwise, the Lake Wind Advisory is still going strong. Winds may not quite last until 9 PM but the decision to cut it off will be made by the next shift as conditions change. The main change to the long-term forecast with this update were the QPF totals for the upcoming low pressure moving through Sunday through Tuesday. QPF north of the Missouri River backed off a bit while areas in south central Montana saw a decent increase. There's still a bit of model disagreement on this but, for now, it seems generally likely that the highest chance of wetting rains will be south of the Missouri River. -thor MORNING DISCUSSION: Synoptic Setup: Forecast begins with hot high pressure situated over the Desert Southwest and a ridge jutting northeast through the Great Plains and Upper Mississippi Valley. A large disturbance that dragged the front through yesterday has allowed its surface low to dwell over southern Saskatchewan letting some lingering moisture enter northeast Montana. Farther west a trough over the coast of the Pacific Northwest is beginning to retrograde and drop southwest off the coast of California. Today into tonight: Strong west winds behind the front are expected along with possible lingering showers across the northern zones as the low exits to the east early today. RAP Model is hinting toward a resurgence of haze across the area Friday morning though the strength/intensity of particle concentration does appear to be less than the last 2 events and does not appear to be much more impactful than haze and limited health concerns in comparison. Timing for the worst of it looks to be around 3AM to Noon across northern zones. Friday through Saturday night: Heat from the Desert Southwest will move itself over the Great Plains and backbuild a ridge northwest over central Montana and the CWA. This will stabilize and cap the atmosphere for dry warmer weather (widespread 90s for highs) into the early weekend. Meanwhile a new trough off he coast of British Columbia will use its momentum to barrel into the back built ridge and form a cold front over central Alberta as it links up with the more southern trough over the California coast. Sunday to Monday night: The cold front is expected to drop down the high Plains of Alberta hitting northeast Montana roughly Sunday afternoon to Sunday evening. If sufficient pacific or monsoonal moisture can gather ahead of the front from the new southwest flow aloft there is a high chance for thunderstorms with a slight chance for severe weather due to mainly gusty winds. However, frontal timing will have to remain in sync with afternoon heating to remain severe. After the thunder exits Sunday night, general shower chances with possible wetting rains should survive through Monday night Tuesday onward: Cool high pressure at the surface and a warming profile with height should generate stable, dry, and partly cloudy conditions through early next week. This warming will be followed with a shortwave ridge axis crossing the area Wednesday and maybe a shortwave trough right behind on Thursday. Though those last two days are currently low confidence being 7 to 8 days out. GAH && .AVIATION... UPDATED: 2100Z FLIGHT CAT: MVFR-VFR DISCUSSION: Smoke and haze is starting to move into the area this afternoon and linger through the day on Friday. Haze has already started reducing visibility at KGGW and is expected to continue with haze reaching KOLF by 00Z, KSDY and KGDV by 06Z. WINDS: West to southwest at 15 to 25 kts, gusting to 30 kts this afternoon. Calming to less than 10 kts overnight. -thor && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory until 9 PM MDT this evening For Fort Peck Lake for Central and Southeast Phillips...Central and Southern Valley...Garfield...McCone...Petroleum. && weather.gov/glasgow
The national radar mosaic for the moment the first event began.
7 drought. Local standard time, as filed.
Ongoing drought conditions in the southern half of Northern Phillips County remained in D2-Severe, while the northern half of the county was in D1-Moderate drought. These conditions continued through the end of September.
Ongoing drought conditions continued across the northern two thirds of central and southeast Phillips County which remained in D2-Severe conditions, while the southern one third remained in D1-Moderate drought. On the last week of September, the southern one quarter of central and southeast Phillips County improved to D0-Abrnormally Dry conditions, while the northern two thirds of the county remained in D2-Severe conditions while and a strip in between those areas remained in D1-Moderate drought.
Ongoing D2-Severe drought conditions continued across the southwestern one quarter of northern Valley County, while the northeastern three quarters remained in D1-Moderate|drought. These conditions remained the same through the end of September.
In Valley County, all but the northeastern corner and the southwestern corner of central and southern Valley County were in D2-Severe drought conditions. The northeastern and southeastern corners of the county were in D1-Moderate drought. These conditions would remain the same through the end of September.
Ongoing drought conditions continued across the far southwestern corner of western Roosevelt County which remained in D2-Severe drought, while the rest of the county remained in D1-Moderate drought. These conditions would remain the same through the end of September.
Ongoing D2-Severe drought conditions continued across the far northeastern one quarter of Garfield County, while the far northern portions of Garfield County bordering Fort Peck Lake remained in D1-Moderate drought. The remaining portion of the northern third of Garfield County remained in D0-Abnormally Dry conditions. The southern two thirds of Garfield County was given no drought classification at all.|During the last week of September, the area of no drought classification moved a bit|northward to along the southern shores of Fort Peck Lake of northwestern Garfield County.
Ongoing D2-Severe drought conditions continued across the northwestern corner of McCone County, while the remainder of the northern third of the county was in D1-Moderate drought. The middle one third of McCone County was in D0-Abnormally Dry conditions. These conditions would remain the same through the end of September.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2023Every state in 2023This day in weather historyWarnings in Montana, September 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: 1129455, 1129563, 1129565, 1129635, 1129642, 1129646, 1129655.