Early April Pattern Change To Bring Annoyingly Chilly Temperatures to Parts of Northern United States

Linda Lam
Published: March 29,2016
April usually brings thoughts or at least hopes of warmer temperatures, but as the calendar turns the page this year that desired warmth may be hard to find for some thanks to a pattern change. As colder air settles into the northern tier of the Lower 48, this could also set the stage for snow chances in the days ahead.
March has been a very warm month for most of the U.S. Numerous locations from the Rockies to the East Coast, with the exception of much of the South, are in position to see a top five warmest March.
(MORE: Warm Records are Crushing Cold Records in 2016)
Heading into early April, however, a surge of arctic air is expected to push southward through central and eastern Canada and into adjacent parts of the northern United States. Details on exactly how far south the cold air will move and how cold temperatures will be are a bit uncertain at this time, but an overall chilly forecast is anticipated for parts of the Upper Midwest, Great Lakes and Northeast.

Chilly Setup

These colder conditions are due to a southward plunge of the jet stream, in response to a blocking ridge of high pressure over the Pacific Northwest, that will allow chillier temperatures to spread from Canada into the Midwest and East.
(MORE: April, Summer 2016 Temperature Outlook)
One of factors that will be playing a role in this April chill is the split the stratospheric vortex underwent in mid-March. This is expected to result in negative Arctic Oscillation conditions in early April, which typically translates to below-average temperatures in the Eastern U.S., with warmer than average conditions in the West.
That said, the latest forecast guidance suggests this invasion of colder temperatures will not make it very far south in the eastern states. Areas closest to the Canadian border from the Great Lakes into the Northeast are currently forecast to see temperatures the farthest below average Saturday into early next week.

Chilly Forecast

Forecast Highs

The colder-than-average temperatures will first make its presence known in the Upper Midwest and Great Lakes this Saturday and Sunday. High temperatures will be 10 to 25 degrees below where they are typically expected to be for the beginning of April for parts of this area starting this weekend.
Highs will likely top out in the 30s and 40s for much of the Northeast and parts of the Great Lakes. Some locations near the Canadian border may not rise out of the 20s.
Along with the cold air, some light snow or snow showers can be expected across the northern Great Lakes on Saturday, followed by the interior Northeast by Sunday.
(FORECASTS: Grand Forks, North Dakota | Kansas City | Cleveland | Baltimore)

Forecast Late Next Week

Low temperatures will be in the 20s and 30s for much of the Upper Midwest and interior Northeast, with teens likely near the Canadian border from northern Minnesota to northern New England.

Forecast AM Lows

(MAP: 10-day forecast)
Widespread record cold temperatures are not currently expected, but for most it will still be an unwelcome change. Many areas will see a temperature drop of 10 to 25 degrees to start April compared to the end of March.
In addition, light snow or a mixture of rain and snow showers may move through parts of the Great Lakes and interior Northeast this weekend.
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