A strong and possibly damaging wind event is expected throughout all of Montana tomorrow. Today started off windy, but the wind has been gradually diminishing throughout the afternoon and evening. The wind will begin to pick back up later tonight and will continue to get stronger tomorrow morning. Tomorrow will be an extremely windy day. 30-55 mph sustained winds are expected, and widespread 60-85 mph gusts are expected. Along the Rocky Mountain Front, 90-100 mph gusts are possible, with a few locations possibly having wind gusts up to 110 mph.
Here is the detailed forecast:
The strongest wind will occur tomorrow morning through early tomorrow evening in western portions of north-central Montana (west of a line from Havre to Lewistown) and midday tomorrow through early tomorrow night in eastern portions of north-central Montana (east of a line from Havre to Lewistown). The wind will gradually diminish from west to east tomorrow evening/night. Due to the forecasted strong winds, a HIGH WIND WARNING is in effect for basically all of Montana for most of tomorrow and part of tomorrow night.
Wind damage is expected tomorrow. Downed trees and broken branches are possible, flying debris are possible, and damage to infrastructure (including roofs and siding) is also possible. There may also be power outages tomorrow, and these power outages could last for hours as it may not be safe for crews to try and get the power back on until after the wind subsides. If you are driving a high-profile vehicle or a vehicle with a trailer it is STRONGLY ADVISED that you do not travel tomorrow and wait until Thursday to do so as travel will be extremely difficult to near impossible. Travel will even be difficult tomorrow for passenger vehicles, especially on north-south oriented roads. Also, if you have any outdoor holiday decorations, make sure they are tied down or brought indoors tonight. Same goes for trampolines and anything else that the wind can easily pick up.
Rain/snow will continue to fall along the Divide tonight, while there will be some scattered rain and a few snow showers east of the Divide, generally after midnight. Rain/graupel/snow showers are likely around Helena tomorrow, generally during the morning, and there are going to be scattered rain, graupel, and snow showers in north-central Montana tomorrow morning as a cold front passes through our area. There are then going to be some scattered snow/rain showers around late tomorrow afternoon through early tomorrow night east of I-15 in north-central Montana as another cold front passes through our area. A few snow squalls are also possible tomorrow, and it will be partly to mostly cloudy.
A WINTER STORM WARNING is in effect from 8pm tonight until 11pm Wednesday for the Glacier area and the Rocky Mountain Front where 4-12+” of snow is possible at and above mountain pass level. A WINTER WEATHER ADVISORY is in effect for the Highwoods and Little Belts until 11pm Wednesday as up to 6” of snow is possible. Whiteout conditions are also possible in these areas tomorrow due to falling and blowing snow. East of I-15 in north-central Montana, a coating to a couple inches of snow is possible through tomorrow night.
It is going to be mild again tonight as lows are going to be in the 30s and low to mid 40s. Tomorrow, highs will be in the 40s and low 50s, but these highs will occur during the morning, with falling temperatures throughout the day.
On Thursday, we are going to have partly to mostly cloudy skies with a few rain and snow showers around in north-central Montana later in the day and scattered snow/rain showers around Helena during the afternoon/evening. The wind will also be weaker on Thursday, but it will still be breezy in some areas as sustained wind speeds are going to be between 10 and 20 mph. It is also going to be cool on Thursday as highs are going to be in the 30s and low 40s (20s in northeastern Montana).
Snow/rain is likely around Helena on Friday and there are going to be a few snow/rain showers around in north-central Montana on Friday, generally in southern portions of north-central Montana, as another disturbance impacts the state. It is also going to be windy and mild on Friday as sustained winds are going to be between 15 and 35 mph, and highs are going to be in the 40s.
Colder temperatures return this weekend as highs are going to be in the 20s and low to mid 30s along the Hi-Line and the 30s and low 40s south of the Hi-Line. On Saturday, there are going to be some isolated snow showers around. There are then going to be a few snow/rain showers around the Helena area and in the mountains on Sunday. We are also going to have partly to mostly sunny skies this weekend. There is also going to be a good breeze around on Saturday as sustained wind speeds are going to be between 10 and 25 mph.
