An embedded low pressure disturbance moving through the region included strong winds, some of which, in excess of 55 mph reached down to the surface across central and northeastern Montana through the morning and mid-day hours.
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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 GGW wrote it up.
An embedded low pressure disturbance moving through the region included strong winds, some of which, in excess of 55 mph reached down to the surface across central and northeastern Montana through the morning and mid-day hours.
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 Dec 12, 9:21 AM MST, 2 hours 28 minutes earlier.
Area Forecast Discussion National Weather Service Glasgow MT 921 AM MST Wed Dec 12 2018 .DISCUSSION... Morning Update (915am MST): Just minor adjustments to the precipitation and wind grids to keep current with observational trends from satellite/radar/surface sources. Temperatures also had to be bumped up by at least 5 degrees across much of the CWA today as temperatures currently are at or have exceeded the morning forecast high temperatures. The High Wind Warning will remain in effect as it was from the morning package. Bigelbach PREVIOUS DISCUSSION: Main challenges continue to be in the near term with the frontal system pushing through the region. The primary cold frontal push will come with a mix of rain and snow showers which could eventually transition to snow. While accumulations should be light, the convective nature could allow some stronger winds just above the surface to mix down, thereby greatly reducing visibilities for a time. Another concern continues to be a few slick surfaces developing tonight as temperatures fall. High wind warning appears on track for elevated locations of the Little Rockies. The Zortman area and locations on the north to south oriented U.S. 191 could face dangerous cross winds with northwest gusts in excess of 60 mph for today. For the remainder of northeast Montana, high winds are not expected but it should still be a windy day, especially with any rain and snow showers that occur this afternoon. Latest 00z guidance shows an upper ridge building over the western U.S. and extending into Montana for the second half of the week behind the current approaching storm system. Thus, expect milder temperatures and drier weather conditions heading into at least the first part of the weekend. The next trough looks to push through with a cold front on Saturday, but with limited moisture with this system, impacts should be minimal. Maliawco && .AVIATION... FLIGHT CAT: VFR to IFR. LLWS: Strong winds above a low level inversion will lead to wind shear concerns over area terminals through about 18-20Z. DISCUSSION: Rain and snow showers today could be accompanied by reduced CIGS and VSYBS at times. The lowest visibilities should come with the steadiest snow showers this afternoon. WIND: Expect winds today to be out of the west to northwest with speeds of 15-25 kts with gusts to 30 kts over the TAF sites today, with weakening winds overnight to 5-15 kts. Tomorrow, southwest winds of 10-20 kts will be likely. Maliawco/Bigelbach && .GLASGOW WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 5 PM MST this afternoon for Southwest Phillips. && weather.gov/glasgow
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
934 AM MST WED DEC 12 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0845 AM NON-TSTM WND GST 11 ENE ZORTMAN 47.96N 108.31W
12/12/2018 M54 MPH PHILLIPS MT MESONET
MESONET STATION MTMAL, MALTA 35S. MAX
SUSTAINED WIND 40 MPH.
0432 AM NON-TSTM WND GST 1 WNW ZORTMAN 47.92N 108.55W
12/12/2018 M48 MPH PHILLIPS MT MESONET
MESONET STATION ALDM8, ZORTMAN 1W.
&&The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
At the Malta South US-191 DOT site, sustained winds of 40 mph were intermittent and did not last for more than 1 hour at a time. The peak wind gust of 59 mph was recorded at 11:49 AM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2018Every state in 2018This day in weather historyWarnings in Montana, December 2018
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: 796696.