By Brian Lada
The first frost and snowfall of the year will arrive over the northern Plains of the United States before the middle of the week.
“A major cold front pushed southward through the Canada Prairies Monday with a strong, Arctic high pressure system building in behind it,” said AccuWeather Canada Weather Expert Brett Anderson.
The air behind this front will be cold enough for several inches of snow to fall over the Canadian Rockies and even in cities such as Calgary and Edmonton on into Tuesday evening.
Snow and cold air are then forecast to make an appearance across Montana and into portions of North Dakota, South Dakota and Wyoming on Tuesday night, although little is expected in terms of snow accumulation.
Snow is likely to stop short of reaching Denver with this outbreak of cold air.
“The chilliest air since last spring will push southward from Canada and across the northern and central Plains, Midwest and the eastern slopes of the Rockies, prior to the middle of September,” said AccuWeather Senior Meteorologist Alex Sosnowski.
This chilly air mass will continue to expand south and east throughout the rest of the week, but the coldest air will remain locked up over the Canadian Prairies and northern Plains.
Frost will be a major concern for those with outdoor plants that are sensitive to freezing temperatures such as flowers and garden plants. This includes plants such as tomatoes, squash, cucumbers and watermelons.
Frost may form several nights in a row across the northern Plains with frost also possible over parts the Upper Midwest during the second half of the week.
Covering your plants early in the night is one way to try to prevent frost from damaging your plants.
“On a broad-term agricultural standpoint, crops such as corn and soybeans are maturing about a week behind average, but with such a bumper crop anticipated, no significant impact is expected by the light spotty frost unless temperatures dip significantly lower than currently forecast,” said Sosnowski.
By the end of the week, the core of the chilly air mass will shift over the Great Lakes and away from the Plains.
However, those across the Great Lakes should not have to worry about temperatures dipping below freezing this weekend. The warm waters of the Great Lakes will cause the air to warm up slightly.
“Provided the sky becomes clear and winds diminish, portions of upstate New York, northern Pennsylvania and interior New England could experience a frost during multiple nights this coming weekend,” Sosnowski said.
As a result, people in the typical early-season cold spots of the Northeast should be prepared to take preventative measures against frost this weekend.