Winter storm warnings have been issued for parts of Montana as snow is expected to cover areas in the northern Rockies and Cascades during the first weekend of summer. It might sound like something Yogi Berra, the late New York Yankees catcher, would have said – a “summer winter storm.” However, it is indeed in the forecast for this weekend. Let’s first delve into the forecast details and then analyze if this weather event is truly unusual.
NWS Alerts:
– Winter weather advisories are in effect for light snow accumulations at higher elevations in western Montana.
– Winter storm warnings have been issued for heavier snow accumulations near Glacier National Park in northwest Montana.
Snow Details:
– The majority of the snow is expected to fall from Saturday night through Sunday morning, with an earlier start near Glacier National Park.
– Snow totals near Glacier National Park could reach 12 to 18 inches at elevations above 6,000 feet, according to the National Weather Service.
– In the rest of the northern Rockies and Cascades, a few inches of snow could fall at elevations as low as 5,000 feet.
Potential Impacts:
– Slushy travel conditions are likely over mountain passes, particularly by Sunday morning, potentially leading to the closure of sections of the Going-to-the-Sun Road in Glacier National Park.
– The heavy, wet, late-season snow combined with wind could result in downed trees and power outages.
– Expect chilly temperatures with lows in the 30s on Sunday and Monday mornings.
How Unusual Is This?
– Snow in June is not uncommon for the Rockies.
– June snowfall has been recorded in cities like Denver, Flagstaff, Salt Lake City, and Tahoe City in the past.
– June snow events have occurred in the Mountain West in recent years, including 2019, 2020, and 2023, with a notable instance in the northern Rockies in July 2016.
Reasons for the Weather:
– The same weather pattern causing a heatwave in the Plains, Midwest, and East is also responsible for the June snow in the West.
– The jet stream is dipping sharply into the Northwest, providing the necessary moisture and lift in the atmosphere for precipitation, along with enough cold air to turn it into snow at higher elevations.
Jonathan Erdman, a senior meteorologist at weather.com, has been reporting on national and international weather since 1996, particularly focusing on extreme and unusual weather events. For more updates, you can contact him on Bluesky, X (formerly Twitter), and Facebook.
