Favorable weather and air pressure patterns directed strong and gusty upper-level winds through the region, some of which were able to mix down to the surface over across portions of northeast Montana.
Every event with a place to put it; 5 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.
Favorable weather and air pressure patterns directed strong and gusty upper-level winds through the region, some of which were able to mix down to the surface over across portions of 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 Dec 19, 9:25 AM MST, 3 hours 20 minutes earlier.
Area Forecast Discussion National Weather Service GLASGOW MT 925 AM MST Mon Dec 19 2016 .SHORT TERM...for northeast Montana...today through Wed... MORNING UPDATE: Changes to the forecast first focused on raising immediate temperatures which were 5 to 15 above predicted values due to chinook affects reaching father east than anticipated. In addition multiple echos are moving across southwestern zones and Lewistown ASOS is reporting snowfall with this passage so heaviest echos are reaching the ground. Therefore... PoPs need to be raised in these areas to reach criteria. GAH PREVIOUS SHORT TERM DISCUSSION: A slight ridge in place over Northeast Montana this morning with a quick-moving trough moving across Western Canada will bring a strong westerly flow over the local region today. in conjunction with the approaching upper trough there is a developing surface low in the lee of the Canadian Rockies that will be producing gusty winds over the local region today. The base of the upper trough slide across Nemont during the late afternoon and early evening will spread low clouds across the area, and maybe some light snow and rain. Wind strength could be sufficient to produce areas of blowing snow. SW Phillips County is already highlighted for blsn. Thickness heights continue their improvement today. That and mixing will help raise temperatures to around 5-10 degrees above normal. Another upper ridge follows for Tuesday for continued above normal temperatures. But with the surface trough moving farther east, westerly winds diminish to around 10-15kt. A weak embedded disturbance is apparent that may kick off some precipitation before noon. It may be rain mixed with snow based on the temperatures. Tuesday night will see the next wave, a fast-moving, tight, miniature cyclone that will march right through Northeast Montana, producing snow and wind. Wednesday the small storm moves east to be replaced by another ridge which will keep temperatures above normal. Templer .LONG TERM...Wed night through Mon... Westerly flow to continue through the end of the week with warm and generally dry weather on Thursday. Models trending toward digging a trof into the Great Basin by the weekend, and spinning up another winter storm system in Wyoming. Uncertainty still high for this system due to wide spread of model solutions. Current expectation is as trof digs into the Great Basin, southwest flow will begin to spread moisture into western Montana on Friday. By Saturday as the trof moves east, colder air will be drawn south and snow will spread into eastern portions of the state. The main focus for the system is currently over southern Montana with most of the snow occuring Saturday and Saturday night before the system sweeps east on Sunday. Forecast timing and position of the snow is expected to change over the next few days. Ebert && .AVIATION... VFR. Flight category reductions to MVFR are possible this afternoon with a few snow showers moving through northeast Montana. Strong winds aloft will result in LLWS until mid morning when the winds should mix down to the surface. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon MST today for Southwest Phillips. && weather.gov/glasgow
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 253 AM MST MON DEC 19 2016 MTZ016>027-059>062-201000- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE- RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS- SOUTHWEST PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT- 253 AM MST MON DEC 19 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER WEATHER ADVISORY FOR BLOWING SNOW REMAINS IN EFFECT FOR SOUTHWEST PHILLIPS COUNTY UNTIL NOON TODAY. INCREASING WEST WINDS ACROSS THE REGION WILL PRODUCE AREAS OF BLOWING AND DRIFTING SNOW THROUGH TONIGHT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
5 high wind. Local standard time, as filed.
The Malta South US-191 DOT site measured sustained winds of at least 40 mph through the mid-day and afternoon hours on the 19th with a peak wind gust of 83 mph at 1:55 PM.
The Malta South US-191 DOT site measured sustained winds of at least 40 mph through the afternoon hours on the 21st with a peak wind gust of 68 mph at 2:45 PM.
Trained spotter 10 NW Larslan measured a 67 mph wind gust. Time is estimated.
The South Sawmill Creek RAWS site recorded a single wind gust of 62 mph. Sustained winds were below 35 mph.
Fort Peck Dam mesonet site measured 58 mph gusts each hour for 3 hours between 11:00 PM on the 20th and 2:00 AM on the 21st. Sustained winds of at least 40 mph continued through 3:00 AM.
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: 669377, 669378, 669375, 669379, 669376.