A plume of Pacific Moisture and westerly upslope flow aloft resulted in periods of snow, heavy at times, along the western aspects of the Coninental Divide. Some of this upslope snow spilled-over to the immediate lee of the Rocky Mountain Front.
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.
A plume of Pacific Moisture and westerly upslope flow aloft resulted in periods of snow, heavy at times, along the western aspects of the Coninental Divide. Some of this upslope snow spilled-over to the immediate lee of the Rocky Mountain Front. In addition, a surface ridge of high pressure building southward from the Canadian Prairies was accompanied by moist, stable, and easterly upslope flow in the low-levels east of the Rocky Mountain Front. Accordingly, additional upslope snow, heavy at times, occurred along the Rocky Mountain Front and spread eastward over the plains of Glacier County, including Browning, as the easterly low-level upslope flow was likely blocked. By the time this snowstorm concluded on Feb 7th, some locations along the Rocky Mountain Front had set new four-day snowfall records. Four-day snowfall totals ranged from 10.5 inches at the Cut Bank CoCoRaHS station to a record 64 inches in St. Mary.
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 5, 10:40 AM MST, 1 hour 14 minutes earlier.
Area Forecast Discussion National Weather Service Great Falls MT 1040 AM MST Sun Feb 5 2017 .UPDATE... Morning update through Monday night to account for latest model runs. Warm frontal boundary remains just south of Great Falls, resulting in fog and light snow this morning. We expect the front to lift north over the next couple of hours for a short time today before retreating back south of the city. The updated forecast still accounts for this front moving north of Great Falls. Temperatures would dramatically warm and precipitation largely end with warm frontal passage this morning before cooling again this evening as the front drops back south of the city. Light snow will redevelop as the front slides back south of the area and continue through much of the night into Monday. Cassell && .AVIATION... Updated 1740z. KGTF resides on the edge of the warm front, and will likely remain that way for the remainder of the morning and early afternoon. Thus, have kept predominant IFR/LIFR conditions through the day. If the front makes it just a few miles north, cigs/vis could briefly become VFR with southwesterly winds, and hedged that way with with a tempo group. However, it must be stressed that confidence is very low as to whether that occurs or not. Otherwise, no major changes to the TAFs with continued deteriorating conditions over much of the Plains from a KGTF to KHVR line northwest. For SW MT locations, expect winds to increase this afternoon as this region resides on the (much) warmer side of the front, with VFR vis and cigs as a result. Winds will diminish this evening with loss of daytime heating/mixing in the valleys, with the exception of KEKS where channeled southerly winds will likely continue through the Madison River Valley. Cassell && .PREV DISCUSSION... /ISSUED 455 AM MST Sun Feb 5 2017/ Today through Tuesday...There are several complicating factors regarding the forecast over the next few days and it should be noted that, in general, confidence is somewhat below average with the current active pattern. For starters, where confidence is high is the anomalous plume of moisture coming off the Pacific leading to a significant, and potentially record or near-record breaking, snowfall along the Rocky Mtn Front. In this area, we still expect an additional 1-2 feet at and above pass level with another foot or so potentially along the immediately adjacent foothills (ie. Babb/Browning areas) and this comes on what has already fallen over the last 24-36 hrs. There has been some concern regarding whether or not the higher snowfall amounts forecast will be realized. However, after scrubbing through model data and coordination with NWS Missoula and WPC, confidence in these amounts is above average. The point here, though, is that it will be a significant snowfall event with significant impacts in that area, especially those traveling over Marias Pass and/or through the Babb/Browning areas. Also, of note, a tightening pressure gradient at the SFC may lead to a period of higher winds later this afternoon through Monday morning with near-blizzard conditions possible over Marias Pass. For the Browning area, it should be stressed that while we are expected a lot of snow, at this time we are not expecting as strong of winds there. That said, some blowing snow will certainly add to the impacts there. But, the most significant impacts from blowing/drifting snow should be confined to Marias Pass. Confidence is also average to above average regarding snowfall amounts along the I-15 corridor from Dutton to Shelby, including the Cut Bank area. For this reason, we will be upgrading the Winter Storm Watch to a Winter Storm Warning in this area as impacts will likely be significant at times in these areas. Confidence also remains above average for snowfall amounts in and around the W. Yellowstone area. Given the incoming snow isn't all that different from antecedent conditions, I feel that impacts will not be as significant as along the Rocky Mtn Front and, therefore, will go with a Winter Weather Advisory there, mainly for the period of heavier snow later tonight through Monday. Where confidence begins to drop some is the remainder of central and SW MT. Definitely more of a sporty forecast. There is a stationary frontal/thermal boundary draped across central Montana at this time. This boundary won't move much today, but it will be a sharp dividing line between milder air trying to advect in from the SW and much colder Canadian air to the north. Even a shift of 10-20 miles could make all the difference for temps this afternoon. Thinking areas from Great Falls to Lewistown and points south have the best shot at mixing out for a brief time this afternoon with temps potentially reaching into the 30s. However, if this boundary doesn't move, or even sags south, temps could be much colder. Areas north of this boundary will remain entrenched in the colder air. And, as moisture overruns the colder air, may lead to some low clouds/patchy fog/light snow along the Hi-line through the day. This boundary will shift north tonight aided by mid-level WAA and should allow more widespread snow to break out from Cut Bank to Havre. South of the front, snow may remain somewhat limited through tonight. However, the front will quickly shift back south tonight allowing snow to spread south as well. The tricky part comes on Monday as a Pacific cold front crosses the area. It now appears that this front will put an end to most of the snow across the Plains/valleys from west to east Monday afternoon as downsloping takes over. Adjusted the forecast to reflect this potential. This may also tend to limit snowfall amounts somewhat over the plains. With this front, thinking there will be a heavier band of snow accompanying it potentially, but it should be brief. All this considered, went with a Winter Weather Advisory for most of the plains, except Fergus County. For Fergus County and the valleys of SW MT, it appears impacts will be limited to the band of snow along the front and feel that impacts won't be significant enough to warrant any winter weather products at this time. But, later shifts will closely monitor the situation. In the wake of the front, some light snow may linger across parts of the CWA into Tuesday, but a gradual decreasing trend in coverage is expected. Martin Tuesday Night through Sunday...Medium range period starts off with models in fairly good agreement but their solutions diverge significantly by late in the week. A surface high pressure system will be centered over central Montana Tuesday night with a moist northwest flow aloft in the wake of the early week storm. Residual snow will continue to affect the western mountains with snow but only a slight chance of light snow or flurries should be expected over the plains. Cold conditions are anticipated Tuesday night with the high pressure system in place but models are in good agreement that the colder air will slide east quite rapidly as an upper ridge develops over the region on Thursday and downslope pressure gradients bring a return of westerly winds. Models may be overdoing the expected amount of warming as they are showing high temperatures on Thursday jumping into the 40s but thickness values seem to be on- track with these temperatures so am leaving them in-place for now. As the flow aloft becomes westerly and continues to strengthen, an Alberta clipper system sweeps by north of the border allowing a weak Pacific front to moderate temperatures a few degrees. This pattern will also keep a chance for showers over the western and southwest mountains with generally dry conditions prevailing at lower elevations for Friday and Saturday. By Saturday night an upper ridge is expected to develop over the eastern Pacific with flow aloft over Montana becoming northerly and another Canadian cold pressure system anticipated for Sunday. mpj && .PRELIMINARY POINT TEMPS/POPS... GTF 37 8 15 -3 / 30 70 90 70 CTB 14 -1 5 -12 / 100 100 100 50 HLN 42 16 24 6 / 30 40 80 70 BZN 45 25 35 13 / 10 30 60 70 WEY 34 27 32 4 / 70 70 90 80 DLN 44 29 42 15 / 20 20 50 50 HVR 19 6 10 -9 / 50 90 90 60 LWT 41 11 22 -2 / 10 30 60 90 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 PM this evening to 8 PM MST Monday Blaine...Cascade...Central and Southern Lewis and Clark... Chouteau...Hill...Judith Basin...Liberty. Winter Weather Advisory from 11 PM this evening to midnight MST Monday night Gallatin...Madison. Winter Storm Warning from 5 PM this afternoon to midnight MST Monday night Eastern Glacier...Eastern Pondera...Eastern Teton... Toole. Winter Storm Warning until midnight MST Monday night Northern Rocky Mountain Front...Southern Rocky Mountain Front. && weather.gov/greatfalls
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
857 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM SNOW 9 NNW LINCOLN 47.08N 112.73W
02/05/2017 M11.0 INCH LEWIS AND CLARK MT MESONET
11 INCHES OF SNOWFALL IN THE LAST 48 HOURS. COPPER CAMP
SNOTEL. ELEVATION 6850 FEET.
&&
NJLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
859 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 AM SNOW 11 SE LINCOLN 46.84N 112.51W
02/05/2017 M8.0 INCH LEWIS AND CLARK MT MESONET
8 INCHES OF SNOWFALL IN THE LAST 48 HOURS. NEVADA RIDGE
SNOTEL. ELEVATION 7020 FEET.
&&
NJLPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GREAT FALLS MT
933 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0907 AM SNOW 11 W HELENA 46.58N 112.25W
02/04/2017 M3.0 INCH LEWIS AND CLARK MT NWS EMPLOYEE
3.0 INCHES OF NEW SNOW OVERNIGHT.
1059 AM SNOW 8 SE ULM 47.35N 111.39W
02/04/2017 M1.5 INCH CASCADE MT TRAINED SPOTTER
1.5 INCHES OF NEW SNOW SINCE 7 PM FEB 3RD.
1100 AM SNOW 3 WNW EAST HELENA 46.61N 111.96W
02/04/2017 M4.5 INCH LEWIS AND CLARK MT ASOS
STORM TOTAL OF 4.5 INCHES IN THE PAST 12 HOURS. CURRENT
SNOW DEPTH IS 11 INCHES AT THE HELENA AIRPORT.
0500 PM SNOW LINCOLN 46.95N 112.68W
02/04/2017 E6.0 INCH LEWIS AND CLARK MT PUBLIC
ESTIMATED 6 INCHES OF NEW SNOW IN THE PAST 24 HOURS.
0700 AM HEAVY SNOW 11 WSW BABB 48.80N 113.67W
02/05/2017 M24.0 INCH GLACIER MT MESONET
24 INCHES OF SNOWFALL IN THE LAST 48 HOURS. MANY
GLACIER SNOTEL. ELEVATION 4900 FEET.
0700 AM HEAVY SNOW 11 SSW EAST GLACIER PAR 48.30N 113.33W
02/05/2017 M17.0 INCH PONDERA MT MESONET
17 INCHES OF SNOWFALL IN THE LAST 48 HOURS. PIKE CREEK
SNOTEL. ELEVATION 5930 FEET.
0700 AM HEAVY SNOW 14 SW HEART BUTTE 48.13N 113.02W
02/05/2017 M18.0 INCH PONDERA MT MESONET
18 INCHES OF SNOWFALL IN THE LAST 48 HOURS. BADGER PASS
SNOTEL. ELEVATION 6900 FEET...
0700 AM HEAVY SNOW 24 W BYNUM 47.92N 112.82W
02/05/2017 M21.0 INCH TETON MT MESONET
21 INCHES OF SNOWFALL IN THE LAST 48 HOURS. MOUNT
LOCKHART SNOTEL. ELEVATION 6400 FEET...
0700 AM HEAVY SNOW 23 W BYNUM 47.92N 112.79W
02/05/2017 M18.0 INCH TETON MT MESONET
18 INCHES OF SNOWFALL IN THE LAST 48 HOURS. WALDRON
SNOTEL. ELEVATION 5600 FEET.
0700 AM HEAVY SNOW 15 SW DUPUYER 48.06N 112.76W
02/05/2017 M11.0 INCH TETON MT MESONET
11 INCHES OF SNOWFALL IN THE LAST 48 HOURS. DUPUYER
CREEK SNOTEL. ELEVATION 5750 FEET.
0700 AM SNOW 20 W AUGUSTA 47.45N 112.81W
02/05/2017 M8.0 INCH LEWIS AND CLARK MT MESONET
8 INCHES OF SNOWFALL IN THE LAST 48 HOURS. WOOD CREEK
SNOTEL. ELEVATION 5960 FEET.
0700 AM SNOW 9 NNW LINCOLN 47.08N 112.73W
02/05/2017 M11.0 INCH LEWIS AND CLARK MT MESONET
11 INCHES OF SNOWFALL IN THE LAST 48 HOURS. COPPER CAMP
SNOTEL. ELEVATION 6850 FEET.
0700 AM SNOW 11 SE LINCOLN 46.84N 112.51W
02/05/2017 M8.0 INCH LEWIS AND CLARK MT MESONET
8 INCHES OF SNOWFALL IN THE LAST 48 HOURS. NEVADA RIDGE
SNOTEL. ELEVATION 7020 FEET.
&&
LATEST 48 SNOWFALL TOTALS IN THE ROCKY MOUNTAIN FRONT...ALONG AND
EAST OF THE CONTINENTAL DIVIDE.
NJLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1052 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1051 AM HEAVY SNOW BROWNING 48.56N 113.02W
02/05/2017 E10.0 INCH GLACIER MT LAW ENFORCEMENT
10 INCHES OF SNOW IN THE LAST 48 HOURS.
&&
NJLPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1054 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1048 AM SNOW 11 W CUT BANK 48.63N 112.57W
02/05/2017 M4.0 INCH GLACIER MT PUBLIC
4.0 INCHES OF NEW SNOW PAST 48-HOURS. STILL SNOWING.
&&
KJPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1058 AM MST SUN FEB 05 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1056 AM HEAVY SNOW 1 N BABB 48.88N 113.44W
02/05/2017 E16.0 INCH GLACIER MT TRAINED SPOTTER
ESTIMATED 12 TO 16 INCHES OF SNOWFALL IN THE LAST 36
HOURS.
&&
NJL3 heavy snow. Local standard time, as filed.
Trained spotter in East Glacier Park measured 31 inches of new snow in less than 48-hours and reported travel was likely impossible along side roads in town.
Browning emergency manager notified WFO Great Falls that a state of emergency had been declared for all of Glacier County. In Browning, nearly everything in town had been closed, including schools, and most roads were impassable.
KFBB-TV reported an Amtrak train, with at least 80 people on board, was stuck near Cut Bank.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2017Every state in 2017This day in weather historyWarnings in Montana, February 2017
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: 673459, 673457, 673458.