e. 700 mb winds) increased and became more westerly across the Rocky Mountain Front during the evening of February 12th through much of the 13th as high pressure ridging over western Montana and the Pacific Northwest was broken-down by a series of weather disturbances.
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.
Low- to mid-level winds (i.e. 700 mb winds) increased and became more westerly across the Rocky Mountain Front during the evening of February 12th through much of the 13th as high pressure ridging over western Montana and the Pacific Northwest was broken-down by a series of weather disturbances. At the surface, a trough east of the Rockies developed and deepened. A tightening surface pressure gradient accompanying this strengthening trough yielded strong and gusty southwesterly to westerly surface winds along the Rocky Mountain Front and most of Glacier County. These strong winds, combined with a significant and loose snow pack, allowed a ground blizzard to affect much of Glacier County.
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 Feb 13, 2:45 PM MST, 1 hour 35 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 245 PM MST Tue Feb 13 2018 .SYNOPSIS... Gusty west to southwest winds will continue through tonight across north-central Montana producing blowing and drifting snow in some areas, particularly along the northern Rocky Mountain Front. In addition, the windy conditions will keep temperatures relatively mild tonight. Winds diminish some late tonight through Wednesday morning before the next weather system arrives from the northwest with a cold front dropping south through the region Wednesday afternoon and evening, followed by a period of accumulating snow through Thursday morning and a return to cold temperatures. && .DISCUSSION... Winds will be the main forecast issue through much of tonight as a lower to mid level wind maximum moves across the northern Rockies with strong lee-side trough and pressure gradient along the east slopes. Blowing and drifting snow impacts continue across portions of north-central MT, especially where winds are strongest along the Rocky Mtn Front. While there will be no relief in wind speeds through this evening, temperatures have warmed to around freezing and this combined with scouring/compaction of the previously loose snowpack should help to gradually improve visibility reductions this evening, though drifting will likely be slower to abate. Winds will act to keep temperatures on the mild side tonight across north-central MT, especially along the east slopes of the Rockies. Shortwave dropping SE though BC tonight will continue south into the Northern Rockies Wed and Wed night with a a surface cold front slipping across the AB border late Wednesday morning and continuing south through the forecast area Wednesday afternoon and night. A band of snow is expected to accompany the frontal passage and follow for several hours with additional snow likely to continue into Thursday morning in northerly upslope flow and deepening cold airmass behind the front. Surface high pressure builds in rather quickly Wednesday night from the north for breezy north winds, likely leading to some drifting and localized blowing of the new snowfall. Total new snow accumulation Wed-Thurs looks to range from around an inch across far northern and southern reaches of the forecast area to 2 to 5 inches for much of central MT with higher amounts across the central and western mountains. Additional winter weather statements are likely for this event later today or tonight. Hoenisch Thursday night through Tuesday...Northwesterly to westerly flow aloft is expected Thursday night through Saturday morning as high pressure ridging aloft builds-in from the west, yet multiple disturbances ripple through the flow aloft. In addition, strengthening surface winds are forecast on Friday into Saturday, especially along the Rocky Mountain Front, due in part to strengthening flow aloft. This period will continue to be monitored for potential high wind highlights. Later Saturday through Tuesday of next week feature another longwave trough aloft and embedded shortwave disturbances overspreading our area from the northwest. In addition, another Arctic front is progged to cross the CWA from north to south Saturday night into Sunday, allowing an overall weakening trend in surface winds to begin across the forecast area. Near-normal temperatures are expected Thursday night into Saturday. Thereafter, a return to below-normal readings should begin Saturday night and continue through Tuesday. Periods of primarily snow are expected during the long term period, with the best potential existing Saturday night into Sunday due to the aforementioned Arctic frontal passage. Jaszka && .AVIATION... Updated 1745Z. Strengthening westerly flow aloft will continue to bring gusty west/southwest surface winds to most n-central MT terminals through tonight with just a slight decrease in wind speeds this afternoon before strengthening occurs again late this evening. Strongest wind gusts, in excess of 50kts at times are occurring along the Rocky Mtn Front, where Blizzard conditions are occurring near the surface. Further east toward KCTB wind gusts to 40kts are expected but may peak near 50kts at times this evening with gusts to 35 kts further east across the plains. Areas of BLSN will reduce visibility at times to around 2SM at KCTB and KHVR. Further south, winds will likely have difficulty penetrating into the KHLN and KBZN valleys through this evening and LLWS issues are possible later this evening through tonight as winds above the valleys increase to 35-45kts. Winds should begin to mix down into the KBZN and KHLN areas late tonight through Wednesday morning. The next southward moving cold front will reach the KCTB and KHVR areas by midday Wednesday with lowering ceilings and developing snow. Hoenisch && .PRELIMINARY POINT TEMPS/POPS... GTF 32 36 2 11 / 10 70 90 70 CTB 30 31 -1 11 / 30 100 70 40 HLN 21 34 8 18 / 10 30 60 50 BZN 18 34 13 20 / 0 30 50 50 WEY 13 28 11 22 / 20 60 70 40 DLN 17 33 14 25 / 0 20 40 20 HVR 26 33 -1 4 / 20 80 80 50 LWT 29 37 3 10 / 10 40 80 70 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 8 PM MST this evening Blaine... Cascade...Central and Southern Lewis and Clark...Eastern Glacier...Eastern Pondera...Eastern Teton...Hill...Judith Basin...Liberty...Southern Rocky Mountain Front...Toole. Blizzard Warning until 8 PM MST this evening Northern Rocky Mountain Front. Flood Warning for an ice jam until further notice central Broadwater County near Townsend on the Missouri River. && http://www.weather.gov/greatfalls
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
145 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 PM BLIZZARD 1 ENE EAST GLACIER PARK 48.45N 113.19W
02/12/2018 GLACIER MT DEPT OF HIGHWAYS
SUSTAINED WINDS OF OVER 35 MPH BEGAN AROUND
9PM ON FEB 12 AND CONTINUE AT THE TIME OF
THIS LSR. FREQUENT GUSTS OF 50 TO 65 MPH
WERE MEASURED. THIS SENSOR DOES NOT REPORT
VISIBILITY, BUT NEARBY WEBCAMS SUGGEST
WHITEOUT OR NEAR WHITEOUT CONDITIONS WERE
OCCURRING AT TIMES OVER THE PAST 12 TO 16
HOURS.
&&
MARTINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
151 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0111 AM NON-TSTM WND GST SAINT MARY RAWS 48.74N 113.43W
02/13/2018 M50 MPH GLACIER MT MESONET
&&
MARTINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
152 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0821 AM NON-TSTM WND GST BROWNING RAWS 48.56N 113.01W
02/13/2018 M51 MPH GLACIER MT MESONET
STRONG WINDS COMBINED WITH FRESH SNOWCOVER
LED TO BLIZZARD CONDITIONS IN THIS AREA.
&&
MARTINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
255 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0421 AM NON-TSTM WND GST DEEP CREEK RAWS 48.36N 113.11W
02/13/2018 M90 MPH GLACIER MT MESONET
STRONG WINDS COMBINED WITH FRESH SNOWCOVER
LED TO BLIZZARD CONDITIONS IN THIS AREA.
&&
MARTINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
256 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0723 AM NON-TSTM WND GST BROWNING MDT 48.54N 112.98W
02/13/2018 M73 MPH GLACIER MT MESONET
STRONG WINDS COMBINED WITH FRESH SNOWCOVER
LED TO BLIZZARD CONDITIONS IN THIS AREA.
&&
MARTINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
257 PM MST TUE FEB 13 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0249 AM NON-TSTM WND GST TWO MEDICINE BRIDGE MDT 48.45N 113.20W
02/13/2018 M65 MPH GLACIER MT MESONET
STRONG WINDS COMBINED WITH FRESH SNOWCOVER
LED TO BLIZZARD CONDITIONS IN THIS AREA.
&&
MARTIN1 blizzard. Local standard time, as filed.
Spotter reported blizzard conditions and very difficult travel conditions due to major blowing and drifting snow in Babb. Peak gust of 81 mph was recorded at 16:20 MST Feb 13th.
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, February 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: 735884.