Montana, 2017Winter Storm in Montana, February 1, 2017
February 1, 2017 · NWS MSO · 2 events in 2 counties and zones
Periods of moderate to heavy snow caused slick roads and a high volume of accidents across west-central and southwest Montana.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
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- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 2
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.
Periods of moderate to heavy snow caused slick roads and a high volume of accidents across west-central and southwest Montana.
What forecasters said that day
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 Missoula, MT wrote its last area forecast discussion before the first event at Jan 31, 8:38 PM MST, 3 hours 22 minutes earlier.
Area forecast discussion, Jan 31, 8:38 PM MST, 3 hours 22 minutes before
Area Forecast Discussion
National Weather Service Missoula MT
838 PM MST Tue Jan 31 2017
.UPDATE...Downgraded some warnings in Idaho and Montana to
advisories for the remainder of the event. Some warnings still
remain in western Montana.
&&
.DISCUSSION...Snow is tapering off in Grangeville, Idaho and on
the Camas Prairie. The same is happening in portions of west
central Montana. Some light snow will continue tonight with icy
conditions, so advisories remain, but the period of highest
impact is over and the warning has been downgraded.
In the southern Bitterroot Valley, moderate to heavy snow is
still being reported with reports of black ice forming in the
Missoula Valley causing dangerous travel conditions at times, so
the warning there remains.
Likewise in southwest Montana from MacDonald Pass to Homestake
Pass and Butte, moderate snow continues so the warning there
remains out.
&&
.AVIATION...Light to moderate snow continues to fall along the
I-90 corridor from the ID/MT border east to the Continental
Divide, south through west-central Montana and north-central
Idaho. We do expect further enhancement with the snow showers for
KMSO this afternoon and evening between 31/2200Z-01/0400. These
showers could greatly reduce the visibility for a period of time
in this time range. KBTM can expect similar conditions as KMSO
through 01/0600Z. Gusty easterly winds of around 15-22kts will be
possible after 01/0900Z KMSO. KGPI will remain mostly clear with
northeast winds sustained around 15kts with gusts up to 25kts
this evening through midnight.
&&
.PREV DISCUSSION... /ISSUED 543 PM MST Tue Jan 31 2017/
UPDATE...Canceled winter weather advisory for Flathead and
Mission Valleys. Downgraded Lower Clark Fork region warning
to an advisory.
DISCUSSION...Much of the steady snow has ended across the
southern Mission Valley and there hasn't been any precipitation
falling towards Kalispell at all today. Satellite and radar trends
do show some weak enhancement going on over the southern Mission
Valley and a phone call to a weather spotter northwest of St.
Ignatius confirmed very light snow. This light snow could
continue for the next several hours. Light to moderate snow is
possible for areas between Frenchtown and St. Regis for the next
several hours. Since we are not expecting any heavier snowfall
rates in this portion of the Lower Clark Fork region, we
downgraded the warning.
PREV DISCUSSION... /ISSUED 248 PM MST Tue Jan 31 2017/
DISCUSSION...The winter storm has produced a wide range of
snowfall amounts all across the region today. We have only
received about an inch of snow here at the Missoula airport but
have received reports of 4 inches in the south hills and even up
to 10 inches in Hamilton. Other reports we have received so far
are 6 inches in Greenough, 4.5 inches in Alberton, up to 8 inches
in Georgetown, and 5.5 inches in Greer, Idaho.
For rest of this afternoon and evening, an increase in snow
intensity is expected as the Canadian cold front interacts with
the pacific moisture over west-central/southwest Montana and over
central Idaho. Periods of moderate to locally heavy snow will be
possible especially between Superior to Frenchtown on I-90, near
the Continental Divide in southwest Montana such as MacDonald and
Homestake pass, and in the Camas Prairie of Idaho. Snow is
expected to begin tapering off late this evening across west-
central Montana and central Idaho, but periods of moderate snow
could continue through tonight over southwest Montana.
Additionally, increased east and north east winds are expected
late this evening and tonight, that along with colder
temperatures, will bring concern for refreeze of wet pavement as
the Canadian cold front moves through. Slick conditions may last
through the Wednesday morning commute.
Light snow will linger in portions of north central Idaho and
west central Montana on Wednesday but overall accumulations will
be light with a decreasing trend during the morning.
There is another wave a moisture expected to move into Lemhi
County Idaho late Wednesday. This wave will move northward
overnight and through Thursday and will also interact with a
shortwave from the north. There is still some question on how far
north area of snow will move, but it has been fairly consistent
that snow will fall at least as far north as Grangeville,
Hamilton, and Butte through Thursday.
The shortwave is forecast to pass late Thursday thus ending the
snow and leaving behind cold conditions for Friday morning.
An active southwesterly pattern will bring snow followed by warmer
temperatures and mixed precipitation through the weekend and early
next week. There may be another cold front on Monday that could
enhance snow and cool temperatures.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory until 5 AM MST Wednesday
Bitterroot/Sapphire Mountains.
Winter Weather Advisory until 5 AM MST Wednesday Potomac/Seeley
Lake Region.
Winter Storm Warning until 5 AM MST Wednesday Butte/Blackfoot
Region.
Winter Weather Advisory until 5 AM MST Wednesday Lower Clark
Fork Region.
Winter Storm Warning until 5 AM MST Wednesday
Missoula/Bitterroot Valleys.
ID...Winter Weather Advisory until 4 AM PST Wednesday
Orofino/Grangeville Region.
Winter Weather Advisory until 11 AM MST Wednesday Eastern Lemhi
County...Western Lemhi County.
Winter Weather Advisory until 4 AM PST Wednesday ABOVE 2000 FEET
for the Lower Hells Canyon/Salmon River Region.
Winter Weather Advisory until 4 AM PST Wednesday Northern
Clearwater Mountains...Southern Clearwater Mountains.
&&In the hours before
Local storm report, Jan 31, 7:45 PM MST, 4 hours 15 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
745 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0742 PM SNOW 1 NNW HAMILTON 46.25N 114.16W
01/31/2017 M3.0 INCH RAVALLI MT TRAINED SPOTTER
SNOW DEPTH 10 INCHES. .
&&
NWS MISSOULA MT
IRIS SYSTEMLocal storm report, Jan 31, 7:50 PM MST, 4 hours 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
750 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0750 PM SNOW 2 ESE HAMILTON 46.24N 114.13W
01/31/2017 M6.0 INCH RAVALLI MT TRAINED SPOTTER
.
&&
NWS MISSOULA MT
IRIS SYSTEMLocal storm report, Jan 31, 8:00 PM MST, 4 hours before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
800 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0754 PM HEAVY SNOW 5 N GRANGEVILLE 46.00N 116.14W
01/31/2017 M7.3 INCH IDAHO ID TRAINED SPOTTER
SNOW WAS HEAVY AT TIMES ESPECIALLY THIS
AFTERNOON.
&&
NWS MISSOULA MT
IRIS SYSTEMLocal storm report, Jan 31, 8:09 PM MST, 3 hours 51 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
809 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0804 PM HEAVY SNOW 1 SW KOOSKIA 46.14N 115.98W
01/31/2017 E5.5 INCH IDAHO ID TRAINED SPOTTER
FROM NOON TO AROUND 3 PM THE VISIBILITY WAS
ABOUT A BLOCK WITH BIG FLAKES.
&&
NWS MISSOULA MT
IRIS SYSTEMLocal storm report, Jan 31, 8:13 PM MST, 3 hours 47 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
813 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 PM HEAVY SNOW GLENWOOD 46.24N 115.83W
01/31/2017 E8.0 INCH IDAHO ID PUBLIC
FACEBOOK REPORT. SNOW CONTINUES.
&&
NWS MISSOULA MT
IRIS SYSTEMLocal storm report, Jan 31, 8:15 PM MST, 3 hours 45 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
815 PM MST TUE JAN 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 PM HEAVY SNOW WEIPPE 46.38N 115.94W
01/31/2017 E7.0 INCH CLEARWATER ID PUBLIC
FACEBOOK REPORT.
&&
NWS MISSOULA MT
IRIS SYSTEMWinter Storm, Missoula / Bitterroot Valleys
- When
- February 1, 12:00 AM MST to 2:00 AM MST
- Where
- Missoula / Bitterroot Valleys forecast zone
- Reported by
- AWOS
- Coordinates
- 46.560, -114.023 (the zone’s center; the record gives no point)
The Hamilton AWOS reported up to 4 hours of quarter mile or less visibility due to moderate and heavy snow. A trained spotter reported 8 to 10 inches of snow in Hamilton. The combination of heavy snow and warm road surfaces during the afternoon led to icy road conditions during the evening commute.
Winter Storm, Butte / Blackfoot Region
- When
- February 1, 12:00 AM MST to 3:00 AM MST
- Where
- Butte / Blackfoot Region forecast zone
- Reported by
- Trained Spotter
- Coordinates
- 46.306, -113.025 (the zone’s center; the record gives no point)
Trained spotters reported 7 inches of snow in Anaconda and 6 inches of snow in Butte with snow drifts up to 2 feet. Discovery ski resort reported 9 inches of new snow in 24 hours.
- Winter Storm
- A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
After NWS Directive 10-1605, the rules offices file Storm Data by.
- High Wind in Washington, February 1 to 2, 2017$500,000 · 61 kt wind · 1 event
- Lake-Effect Snow in New York, February 1 to 2, 2017$70,000 · 3 events
- Drought in Georgia, February 1 to 28, 201738 events
- Drought in Oklahoma, February 1 to 28, 201723 events
- Drought in Oklahoma, February 1 to 28, 201719 events
- Drought and Cold in Alabama, February 1 to 28, 201714 events
- High Surf in Hawaii, February 1 to 4, 201714 events
- Winter Storm in Montana, February 1, 201711 events
- Drought in Massachusetts, February 1 to 28, 20179 events
- Drought in Arkansas, February 1 to 28, 20177 events
- Winter Weather in Colorado, February 1 to 2, 20177 events
- Winter Storm and Winter Weather in Wyoming, February 1 to 2, 20175 events
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: 672790, 672823.