Strong westerly flow aloft delivered gusty westerly surface winds, along with scattered showers and mountain snow along the Divide and over portions of Central/North-central Montana on Monday October 12th. In addition, a few of these showers produced some lightning strikes along with moderate downpours of rain. This activity was expected to continue into the evening hours, before diminishing with the loss of daytime heating. The High Wind warning was continued due to sustained winds and gusts remained within striking distance of criteria values. There was a brief period of quiet weather as
transient ridging quickly traversed the region Monday night. The first sign of
the next weather maker was felt along the Divide Tuesday morning as a brief period of accumulating snow developed for locations above 5000 ft. The Winter Weather Advisory still looked good as of Monday afternoon as it appeared there could be some impacts to travel and outdoor interests before the warmer air moves in and inhibited snow accumulation. This area of precipitation then moved over the remainder of the CWA by Tuesday afternoon but snow levels were expected to rise above 7000 ft by afternoon.
The focus then began to shift toward the potential strong winds from Tuesday afternoon into Wednesday morning as a wide swath of very strong upper level winds move into North-central and Southwest Montana. There was still some uncertainty on Monday whether these winds would translate to the surface wind gusts in excess of 60 mph, but the possibility looked best over the higher terrain. The area of greatest concern was areas south and west of a Lewistown, to Great Falls, to Cut Bank line where the strongest H700 winds of 50-70kts were expected to reside through Wednesday morning; which had the potential to make travel over mountain passes like MacDonald, Bozeman, Norris Hill, and Deep Creek hazardous as this looked like an ideal setup for high winds to materialize given a strong west- to-east flow. Given the situation, the current High Wind Watch was continued. Late Tuesday night into Wednesday morning, snow levels began to fall once again as colder air filled in on the back side of the system. This is when some lower elevation locations had the potential to see some light
accumulating snow over portions of North-central Montana, in addition to locations along the divide and the Central Mountains. Snowfall accumulations of 3-6 appeared possible along the Continental Divide and in the mountains of Central and North
Central Montana during the day on Wednesday, with even a dusting to up upwards of 2 over portions of the plains. especially along the Montana Hwy 200 corridor. A Winter Weather Advisory was issued on Tuesday for this snow. In addition to precipitation, another bout of high wind criteria wind speeds/gusts occurred during the morning and early afternoon hours across nearly the entire CWA (save for the Hi-Line east of Shelby) on Wednesday. Some mountain snow did occur Wednesday night that was reported early Thursday morning.

High Wind in BEAVERHEAD, MONTANA
From 13-OCT-20 19:16:00 to 13-OCT-20 19:16:00 (MST-7)
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station wrsm8 wise river raws.

High Wind in BROADWATER, MONTANA
From 13-OCT-20 19:54:00 to 13-OCT-20 19:54:00 (MST-7)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Elkhorn raws.

High Wind in EASTERN GLACIER, MONTANA
From 13-OCT-20 20:00:00 to 13-OCT-20 20:00:00 (MST-7)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Logan pass (gnp).

High Wind in GALLATIN, MONTANA
From 13-OCT-20 20:04:00 to 13-OCT-20 20:04:00 (MST-7)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Yellow mule raws.

High Wind in FERGUS, MONTANA
From 13-OCT-20 13:52:00 to 13-OCT-20 13:52:00 (MST-7)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Judith peak raws.

High Wind in GALLATIN, MONTANA
From 13-OCT-20 21:00:00 to 13-OCT-20 21:00:00 (MST-7)
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station bbcst 11.1 ne bozeman (avalanche).

High Wind in CASCADE, MONTANA
From 13-OCT-20 09:02:00 to 13-OCT-20 09:02:00 (MST-7)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Monarch canyon (mt dot).

High Wind in BEAVERHEAD, MONTANA
From 13-OCT-20 21:14:00 to 13-OCT-20 21:14:00 (MST-7)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Big hole pass (mt dot).

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 13-OCT-20 22:04:00 to 13-OCT-20 22:04:00 (MST-7)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Measured gust of 55 knots.

High Wind in BEAVERHEAD, MONTANA
From 13-OCT-20 22:10:00 to 13-OCT-20 22:10:00 (MST-7)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Asos station kdln dillon.

High Wind in BEAVERHEAD, MONTANA
From 14-OCT-20 00:05:00 to 14-OCT-20 00:05:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station hrkm8 harkness raws.

High Wind in CASCADE, MONTANA
From 14-OCT-20 00:45:00 to 14-OCT-20 00:45:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station fw1843 great falls.

High Wind in MADISON, MONTANA
From 14-OCT-20 01:00:00 to 14-OCT-20 01:00:00 (MST-7)
Magnitude: 62.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station yctim 6.3 w big sky (avalanche).

High Wind in BLAINE, MONTANA
From 14-OCT-20 03:18:00 to 14-OCT-20 03:18:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station fw1843 great falls.

High Wind in FERGUS, MONTANA
From 14-OCT-20 03:52:00 to 14-OCT-20 03:52:00 (MST-7)
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station jpkm8 judith peak raws.

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 14-OCT-20 06:28:00 to 14-OCT-20 06:28:00 (MST-7)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station 301005 sieben.

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 14-OCT-20 07:06:00 to 14-OCT-20 07:06:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Asos station khln helena ap asos.

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 14-OCT-20 10:24:00 to 14-OCT-20 10:24:00 (MST-7)
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station mtmdp macdonald pass (mt dot).

High Wind in MADISON, MONTANA
From 14-OCT-20 12:45:00 to 14-OCT-20 12:45:00 (MST-7)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station mtm17 3.5 se virginia city (mt-meso).

Winter Weather in JEFFERSON, MONTANA
From 14-OCT-20 18:00:00 to 15-OCT-20 09:13:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter estimated 4.5-5 of snow fell overnight and into this morning.

High Wind in MADISON, MONTANA
From 13-OCT-20 22:00:00 to 13-OCT-20 22:00:00 (MST-7)
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station yctim 6.3 w big sky (avalanche).

High Wind in GALLATIN, MONTANA
From 12-OCT-20 10:00:00 to 12-OCT-20 10:00:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station bbcst 11.1 ne bozeman (avalanche).

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 12-OCT-20 13:30:00 to 12-OCT-20 13:30:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Asos station khln helena ap asos.

High Wind in JUDITH BASIN, MONTANA
From 12-OCT-20 13:43:00 to 12-OCT-20 13:43:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Awos station k1bm bravo.

High Wind in FERGUS, MONTANA
From 12-OCT-20 13:52:00 to 12-OCT-20 13:52:00 (MST-7)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station jpkm8 judith peak raws.

High Wind in BROADWATER, MONTANA
From 13-OCT-20 19:54:00 to 13-OCT-20 19:54:00 (MST-7)
Magnitude: 53.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station ekhm8 elkhorn raws - 8 w townsend.

High Wind in BROADWATER, MONTANA
From 12-OCT-20 13:54:00 to 12-OCT-20 13:54:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Southwesterly sustained 32 gust 57 mph. mesonet station ekhm8 elkhorn raws - 8 w townsend.

High Wind in MADISON, MONTANA
From 13-OCT-20 22:00:00 to 13-OCT-20 22:00:00 (MST-7)
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station ycams 5.7 w big sky (avalanche).

High Wind in MADISON, MONTANA
From 13-OCT-20 17:00:00 to 13-OCT-20 17:00:00 (MST-7)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station yctim 6.3 w big sky (avalanche).

High Wind in JUDITH BASIN, MONTANA
From 13-OCT-20 18:02:00 to 13-OCT-20 18:02:00 (MST-7)
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Awos station k1bm bravo.

High Wind in EASTERN GLACIER, MONTANA
From 13-OCT-20 17:15:00 to 13-OCT-20 17:15:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station ew5772 cut bank.

High Wind in JUDITH BASIN, MONTANA
From 13-OCT-20 18:01:00 to 13-OCT-20 18:01:00 (MST-7)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station mtgys geyser (mt dot).

High Wind in MEAGHER, MONTANA
From 13-OCT-20 18:25:00 to 13-OCT-20 18:25:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station k7s6 3.6 s white sulphur springs (gtfwfo).

High Wind in JUDITH BASIN, MONTANA
From 12-OCT-20 13:58:00 to 12-OCT-20 13:58:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Westerly sustained 41 gust 58 mph. awos station k1bm bravo.

High Wind in SOUTHERN LEWIS AND CLARK, MONTANA
From 12-OCT-20 14:44:00 to 12-OCT-20 14:44:00 (MST-7)
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Northwesterly sustained 29 gust 57 mph. mesonet station 301005 sieben.

High Wind in GALLATIN, MONTANA
From 12-OCT-20 16:27:00 to 12-OCT-20 16:27:00 (MST-7)
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station mtbzh bozeman pass (mt dot).