Winter Storm and Flood in Montana, January 11 to 12, 2014

The HADS sensor at Marias Pass reported a total storm precipitation of 0.67 which could have equated to around 6 inches of snow, matching the nearby SNOTEL measurements. A NWS employee reported blowing snow with approximately 5 of snow on the ground as they drove through Marias Pass around 1 pm MST on Jan. 12. An avalanche forecaster reported just under an inch of precipitation mostly in the form of rain. They also reported two avalanches that occurred from natural triggers, but did not affect US-2. The Fielding RAWS sensor recorded a wind gust of 51 mph at 2:42 pm MST on Jan. 11. Other precipitation amounts include: 1.27 Hungry Horse Dam COOP and 0.42 West Glacier COOP.

A NWS employee observed a small stream that had ran over the Old East Highway northwest of Florence. The combination of rain and snow melt and a cold ground, created conditions for the overland flooding.

As the strong cold front passed through around 1 pm MST on Jan. 11, wind gusts between 45 and 52 mph were felt near populations centers such as Kila and Libby. At 3:06 pm MST, the Zonolite RAWS sensor located at 4,204 ft., 8 miles east-northeast of Libby, recorded a wind gust to 65 mph. The Blacktail Ski Area reported very strong winds that blew down trees across power lines on their access road. Fire personnel responded to several downed trees on power lines between Marion and Kila by 4 pm. MST.

The MT DOT sensor located at milepost 47 on Highway 83 measured a gust to 51 mph at 1:59 pm. The Missoula 911 dispatch reported that there were trees down along Highway 200 and 83 due to the wind. The Snowbowl Ski Resort has to shut down two ski lifts due to the strong winds.

A person from the public located in Hall reported strong gusty winds near 60 mph. There were a few trees down, mainly dead Lodgepole Pine with diameters around 16 inches at the base. The MT DOT sensor located 8 miles north of Avon on Highway 141, recorded a peak wind gust to 59 mph while its highest sustained wind speed was 45 mph. Other wind reports include: 58 mph 3 miles NNW Racetrack and 53 mph 2 miles WSW of Deer Lodge. The combination of the recent rains and high winds helped to dislodge several rocks onto MT-1 at Flint Creek Hill by the late afternoon.

A cold front pushed south and east across the Stevensville area around 2 pm MST and wind gusts were close to 30 mph. Radar echoes revealed showers behind the front which affected the area for an hour afterwards. A National Weather Service employee observed a mountain wave developing behind the cold front across the northern Bitterroot Valley. A person from the public located 6 miles south of Lolo, recorded 88 mph on their home anemometer sometime between 2:30 and 3:15 pm MST. They reported roof shingles blown off their roof and a tree limb fell on their house. Three other homes in that area also saw shingle damage and a few trees were blown down. A weather spotter located 2 miles west-northwest of Stevensville estimated that a 60 mph wind gust occurred at 2:57 pm MST. They reported shingle damage and the top of a tree blew off. The wind gust occurred simultaneously with a rain and snow shower.

When the cold front passed through Deer Lodge Airport around 3:20 pm MST, visibility dropped to one-quarter mile due to snow and blowing snow while winds gusted up to 53 mph. These similar conditions were reciprocated at MacDonald Pass by 4:05 pm and at Homestake Pass by 5:10 pm MST with the front. Snow and blowing snow was reported by a spotter in Anaconda from 4:45 pm to 6 pm MST, and they measured 3.5 of snow in 4 hours. Other snowfall amounts include: 7.5 Georgetown Lake, 6 Discovery Ski Resort and 1.5 7 miles south of Butte.

After the cold front passed through, air temperatures remained warm in the 30's and 40's and this aided the development of rain & snow showers. After sunset, weather spotters from Libby southward reported freezing rain that formed a glaze of ice on untreated surfaces. Snow covered US-2 from Happy's Inn to Marion, and there were reports of periods of heavy snow and wind gusts to 40 mph associated the showers. A weather spotter reported a foot of standing water on the Champion Haul Road near US-2 in Libby at 9:38 pm MST on Jan. 11. Total snowfall amounts include: 8 Blacktail Ski Resort, 6 at MacGregor Pass Rd. or 10 miles WSW of Marion, 2 5 miles SW of Marion.

The Lost Trail Ski Resort measured a storm total snowfall of 13.5 in 13 hours and 34 minutes. The MT DOT required chains on towing vehicles at Lolo pass Saturday evening, Jan. 11 through the morning of Jan. 12. From 8 pm MST to 12 am MST Jan. 12, the Lolo Pass SNOTEL reported 4 of heavy snow. Lolo Pass received 14 inches of snow with 2.20 of snow water equivalent from Jan. 10-12.

The Lookout Pass Ski area reported 10 of snow that fell in 11 hours through 6:25 am MST Jan. 12. The MT DOT sensor at Lookout Pass reported wind gusts between 25 and 39 mph from 8 pm to 11:26 pm Jan. 11. The strong winds combined with moderate to heavy snow, most likely caused blowing snow which worsened visibilities. An automobile accident occurred at Lookout Pass around 7:35 pm MST and closed all lanes in both directions on Interstate 90 for some time.

The sheriff in Hamilton reported up to 2 of snow fell associated with snow bands. Other reports include: 1.5 Florence and 4 in Grantsdale.