Wednesday, July 6, 2016

Winter Will Rudely Interrupt Summer Across the Northern Rockies This Weekend

Tom Moore
Published: July 6, 2016
In the coming days, a reminder of winter is about to hit one region of the country.
If you live in, or will be visiting parts of the northern Rockies, you'll have to be prepared for some rapid changes in weather conditions this weekend. Summer weather will give way to winter-like conditions as the higher elevations of western Montana and northwest Wyoming are likely to experience cold rain and even some snow.
Beginning on Saturday night, much colder air will rush into the northern Rockies as a trough of low pressure aloft (dip in the jet stream) swings into the region.
High temperatures will only reach the 50s and 60s in the lower elevations on Sunday, with higher elevations remaining in the 40s. These temperatures will be more than 20 degrees below average for this time of year.
(MORE: Heat, Humidity Rising in the Plains, East)

Colder temperatures are expected in the northern Rockies on Sunday.
Along with the chill, a cold rain will develop across the lower elevations on Sunday. Rain will turn to snow in some higher elevations by late Sunday, and snow will continue through Monday morning. Snow levels could drop to 6,500 feet by Sunday night, and wintry precipitation is expected to fall around tourist attractions like Glacier National Park.
Snow accumulations are expected to be light, except for the highest mountain peaks. A very light accumulation of snow could extend down into northwest Wyoming as well.

Snowfall Forecast
The National Weather Service at Missoula, Montana, issued a message for those who have outdoor activities planned in these areas over the weekend and into Monday. They indicated that with temperatures more than 20 degrees below average, outdoor activities will be impacted by rain and cold, with low visibility in the mountains.

Hypothermia In Summer?

During the summer, cold blasts like this one can arrive in a hurry and can make many unprepared people susceptible to hypothermia. Hypothermia is a medical emergency that occurs when your body temperature dips below 95 degrees. Left untreated, hypothermia can lead to failure of your heart and respiratory system, which can be fatal.
(MORE: Here's What Happens When You Have Hypothermia)
The Mayo Clinic has some great tips to prevent hypothermia. They say to follow the acronym "COLD" - cover, overexertion, layers, dry.
  • Cover: Wear a hat or protective clothing to prevent heat from escaping from your head, neck or face. Wear mittens to cover your hands.
  • Overexertion: Avoid activities that cause you to sweat. The combination of wet clothing and cold temperatures cause you to lose body heat.
  • Layers: Wear loose-fitting clothes in layers. Water-repellent material is best.
  • Dry: Stay as dry as possible. Be especially careful to keep your hands and feet dry.
Snow in July is actually not that uncommon in Montana and surrounding states during July. On July 27,2015, there was a significant snowfall across the northern Rockies. Up to 8 inches blanketed the higher elevations of western Montana, while accumulating snow extended down to Jackson Hole, Wyoming.
Tim Ballisty @IrishEagle
Snow in July. Silver Gate, Montana. By Don Taylor. July 28, 2015. Shared on @NWSBillings FB page.

In the lower elevations, cities like Missoula had daytime highs in the upper 40s, which is about 35 degrees below average for this time of year. This time, it will not be nearly as cold and the snow will be much less extensive.


Jet Stream forecast Sunday night (GFS model) shows a cold trough over the northern Rockies

Setup for July Snow and Cold

Friday and Saturday will actually be quite pleasant across the region with high temperatures in the 70s in the lower elevations. As mentioned earlier, a significant trough will swing eastward into the northern Rockies on Sunday and Sunday night.
The result will be precipitation in the form of cold rain, with snow in the highest elevations.
(MORE: Weather Terms You've Heard, But Probably Don't Know What They Mean)
Low pressure will develop at the surface, and it will drag a cold front eastward from Idaho through Montana and Wyoming on Saturday and Saturday night. Temperatures will drop significantly behind the front on Saturday night.
The low will intensify on Sunday night and will bring down more cold air from Canada on the heels of a chilly and gusty northwesterly winds. The unseasonable chill will remain on Monday.
Please prepare accordingly for rapidly changing conditions if you happen to be outdoors in these areas.
MORE: Montana, Wyoming Snow - July 27, 2015
Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)