Ice jam flooding was reported along the Madison River, near Ennis, on the early afternoon of December 27th. The jam also caused flooding along Odell Creek.
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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 TFX wrote it up.
Ice jam flooding was reported along the Madison River, near Ennis, on the early afternoon of December 27th. The jam also caused flooding along Odell Creek.
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 Dec 27, 10:20 AM MST, 1 hour 55 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 1020 AM MST Tue Dec 27 2016 ...Update to Aviation... .UPDATE... Windy conditions will persist today with gusts 60 to 70 mph along the Rocky Mountain Front and 50 to 60 mph gusts over the adjacent plains and portions of southwest Montana. Pacific moisture will spread over the area today with light snow across the mountains, but downslope winds will keep the plains dry, windy and mild. The highest snow amounts will be along the Continental Divide where 3 to 5 inches of snow are possible above pass level. The remainder of the forecast is on track so no further changes were made. MLS && .AVIATION... Updated 1720Z VFR conditions will prevail through late Wednesday morning for most of the forecast area. However, mountains will be obscured by clouds and snow at times. Strong and gusty westerly winds will prevail across north central Montana through much of the period as well. Additionally, areas of snow and blowing snow could produce IFR/MVFR conditions at times, especially across Southwest Montana. Clouds and areas of light snow diminish after 02Z Wednesday. && .PREV DISCUSSION... /ISSUED 615 AM MST Tue Dec 27 2016/ Quick update as of 615 am...Strong south winds of 25 to 40 mph with gusts to 65 mph at times are blowing through the U.S. Highway 287 valley of Madison County, and they are expected to persist throughout the day. This includes the Ennis and Norris Hill areas. Cannot rule out other areas of the county getting similar winds, including the Raynolds Pass area. Have therefore issued a High Wind Warning for Madison County through 5 pm. After then, the winds will shift more westerly and not be as favorable for strong sustained winds. Coulston Today through Thursday...A disturbance in a strong westerly flow aloft will continue to bring these winds down to the surface today, especially along the Rocky Mountain Front and the adjacent plains, where a High Wind Warning is in effect until 11 pm this evening. Gusts in excess of 75 mph have already occurred close to the Front, and gusts of 55 to 65 mph will likely redevelop by late morning to the plains along and west of Interstate 15. Gusts of 40 to 50 mph will be possible east of Interstate 15. Overall, these winds will cause areas of blowing snow, especially close to the Rocky Mountain Front, where near whiteout conditions are possible. This disturbance will also continue to bring heavy snow at times to the mountains of Western Montana, so will continue the Winter Storm Warning for the Rocky Mountain Front due to significant measurable snow over the passes, along with reduced visibility in blowing snow. Snow will also fall in Southwest Montana into this evening. Though accumulation will be light in the valleys, better accumulation is likely at and above mountain pass level, and gusty southwest winds will blow through favored canyons as well, causing reduced visibility in blowing snow. Have therefore expanded the Winter Weather Advisory to cover the entire area. The snow and wind will decrease overnight through Wednesday as the disturbance exits the area and winds aloft become more northwesterly. A high pressure ridge will then build into the area for Thursday, keeping the area mostly dry (except for some snow showers over the Rocky Mountain Front) with continued breezy southwest winds. The winds today will warm temperatures to around 5 degrees above normal over the plains, but cooler air trapped in the southwest valleys will likely keep temperatures near to slightly below normal there. In the wake of the disturbance, most of the forecast area will then have near normal temperatures through mid-week. Coulston Thursday night through Tuesday...Medium range models are in much better overall agreement with regards to this period. A shortwave trough from the Gulf of Alaska will help break down the high pressure ridge and force it west back out onto the Pacific Ocean Thursday night through Friday night. This will put most of the country under the influence of a broad upper level trough, with the forecast area under a persistent northerly flow aloft. This first shortwave will help swing a Canadian cold front through the area. Gusty westerly winds ahead of the front will shift more northerly behind it, bringing a good chance for at least light measurable snow and colder than normal temperatures. Another shortwave trough will bring a second cold front through the area on Sunday, for another good chance of snow and a more substantial shot of colder air that will linger into the early part of the week. At this point, it appears that temperatures will gradually cool through this period, with Monday night lows falling into the single digits and teens below zero and Tuesday's highs only rebounding into the single digits above zero. Will continue to monitor this trend for potential winter weather highlights. Coulston && .PRELIMINARY POINT TEMPS/POPS... GTF 33 26 32 18 / 20 10 10 0 CTB 32 24 30 18 / 10 10 10 0 HLN 33 18 29 10 / 20 20 10 0 BZN 28 12 28 8 / 30 20 20 0 WEY 16 6 20 -1 / 90 60 30 10 DLN 26 12 27 7 / 40 20 10 0 HVR 34 20 32 14 / 20 10 10 0 LWT 32 21 28 14 / 20 10 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 11 PM MST this evening Cascade...Eastern Glacier...Eastern Pondera...Eastern Teton...Judith Basin... Liberty...Toole. Winter Weather Advisory until 5 AM MST Wednesday Beaverhead... Broadwater...Central and Southern Lewis and Clark...Gallatin... Jefferson...Madison...Meagher. Winter Storm Warning until 5 AM MST Wednesday Northern Rocky Mountain Front...Southern Rocky Mountain Front. High Wind Warning until 5 PM MST this afternoon Madison. High Wind Warning until 11 PM MST this evening Northern Rocky Mountain Front...Southern Rocky Mountain Front. && weather.gov/greatfalls
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
626 AM MST TUE DEC 27 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0452 AM HIGH SUST WINDS 4 NNE MCALLISTER 45.50N 111.70W
12/27/2016 E45 MPH MADISON MT DEPT OF HIGHWAYS
58 MPH WIND GUST AT 452 AM ON NORRIS HILL. ESTIMATED
SUSTAINED WIND AVERAGE OF 45 MPH FROM 4 AM THROUGH 5 AM.
SUSTAINED WIND RANGED FROM 40 MPH TO 52 MPH DURING THAT
TIME.
0452 AM NON-TSTM WND GST 4 NNE MCALLISTER 45.50N 111.70W
12/27/2016 M58 MPH MADISON MT DEPT OF HIGHWAYS
58 MPH WIND GUST AT 452 AM ON NORRIS HILL. ESTIMATED
SUSTAINED WIND AVERAGE OF 45 MPH FROM 4 AM THROUGH 5 AM.
SUSTAINED WIND RANGED FROM 40 MPH TO 52 MPH DURING THAT
TIME.
&&
COULSTONPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
628 AM MST TUE DEC 27 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0415 AM NON-TSTM WND GST 5 SE ENNIS 45.27N 111.65W
12/27/2016 M48 MPH MADISON MT AWOS
48 MPH WIND GUST AT ENNIS BIG SKY AIRPORT AT 415 AM.
GUSTS HAVE BEEN OVER 40 MPH SINCE 135 AM.
&&
COULSTONPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
633 AM MST TUE DEC 27 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0253 AM NON-TSTM WND GST MALMSTROM AFB 47.51N 111.18W
12/27/2016 M58 MPH CASCADE MT ASOS
58 MPH WIND GUST AT MALMSTROM AFB AT 253 AM. ESTIMATED
SUSTAINED AVERAGE WIND OF 42 MPH FROM 138 AM UNTIL 258
AM. SUSTAINED WINDS RANGED FROM 39 MPH TO 46 MPH DURING
THIS TIME.
0253 AM HIGH SUST WINDS MALMSTROM AFB 47.51N 111.18W
12/27/2016 E42 MPH CASCADE MT ASOS
58 MPH WIND GUST AT MALMSTROM AFB AT 253 AM. ESTIMATED
SUSTAINED AVERAGE WIND OF 42 MPH FROM 138 AM UNTIL 258
AM. SUSTAINED WINDS RANGED FROM 39 MPH TO 46 MPH DURING
THIS TIME.
&&
COULSTONPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GREAT FALLS MT
636 AM MST TUE DEC 27 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0253 AM HIGH SUST WINDS MALMSTROM AFB 47.51N 111.18W
12/27/2016 E42 MPH CASCADE MT ASOS
58 MPH WIND GUST AT MALMSTROM AFB AT 253 AM. ESTIMATED
SUSTAINED AVERAGE WIND OF 42 MPH FROM 138 AM UNTIL 258
AM. SUSTAINED WINDS RANGED FROM 39 MPH TO 46 MPH DURING
THIS TIME. WINDS ALSO CAUSED SNOW DRIFTS ON NEARBY U.S.
HIGHWAY 87...TEMPORARILY BLOCKING THE EAST BOUND LANE
AND CAUSING LAW ENFORCEMENT TO DETOUR TRAFFIC.
&&
CORRECTED REMARKS
COULSTONPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
831 AM MST TUE DEC 27 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM NON-TSTM WND GST BABB 48.86N 113.44W
12/27/2016 M73 MPH GLACIER MT TRAINED SPOTTER
&&
MPJThe national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
Emergency management reported an ice jam on the Madison River causing flooding near Ennis. The flooding was occurring along portions of the Madison River and Odell Creek. Water was covering the US-287 bridge near Ennis, at mile marker 48.2.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2016Every state in 2016This day in weather historyWarnings in Montana, December 2016
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: 664636.