There are opportunities for snow this week and they include the Upper Midwest, northern New England and neighboring Canada.
Last week snow fell on parts of the northern Plains, Denver and Cheyenne and barely reached the highest elevations of the Northeast late this past weekend.
This week, cold air will continue to nose southward from the polar regions and will try to hook up with weak storm systems along the Canada/United States border in two separate events. The pattern will extend the chance of the first snowflakes of the season to some northern tier locations.
While temperatures will be marginal in both cases, a few degrees can make the difference between all rain and wet snow mixing in for a time.
As a disturbance and surface cold front swing across the Great Lakes, some wet snowflakes can make an appearance in portions of Wisconsin, upper and northern lower Michigan and central Ontario Wednesday. A second disturbance could bring another opportunity Wednesday night into Thursday evening. Cities that may get a little snow include Duluth, Minn. and Marquette, Mich., and Thunder Bay, Ont. A few snowflakes could reach as far south as Green Bay, Wis., and Traverse City, Mich.
The first of the two systems are then forecast to move on to northern upstate New York, Vermont, northern New Hampshire, northern and western Maine, and portions of Quebec Wednesday night. There is a chance of rain mixing with or changing to a little wet snow before ending. The second disturbance would swing through Thursday night with the chance of a rain/snow mix or a period of snow. Cities that have a chance at getting a little snow from one or both systems include Ottawa, Montreal and Quebec City. Snowflakes could reach as far south as low elevation locations such as Massena, N.Y, Burlington, Vt., and Caribou Maine. A little snow is more likely over the mountains northern New England, southern Quebec and the peaks in the Adirondacks.
According to Expert Senior Meteorologist Brett Anderson, "In both cases in both areas, the second of the two disturbances may have a little more cold air established to work with. So the second system has a slightly greater chance at allowing snow to reach the ground in more places."
In the wake of the potential for a touch of snow for northern areas, the coldest air of the season so far will spread a killing frost and freeze farther east than any such air mass so far this autumn. The upcoming frost and freeze can reach the I-95 corridor of the Northeast.
Elsewhere, a little more snow was spreading southward over the foothills, eastern slopes of the Rockies and some of the High Plains in Alberta and eastern British Columbia Wednesday.
A storm rolling into California this week may, by this weekend, could bring heavy high country snow to portions of Colorado, northern New Mexico and Utah's Wasatch Mountains.
Severe thunderstorms return near Little Rock, threatening areas from Oklahoma City to Dallas to close out Wednesday evening.
Tropical Depression Two has lost its battle to become the next Atlantic tropical storm, but it will still increase shower activity across the Caribbean to end the week.
A thick, massive band of mayflies traveling along the Mississippi River created a swarm so intense it became visible on National Weather Service radars on July 20, 2014.
Fresh cooler and less humid air will settle over the Boston area for Thursday and Friday.
Warm and humid air in place over much of the Northeast at midweek is contributing to the risk of drenching, gusty and locally severe thunderstorms on Wednesday.
Severe thunderstorms are dropping down through the South Central states to close out Wednesday.
Hurricane Delores, west of Baja California, causes high surf along the Southern California coast.
Minneapolis, MN (1987)
10 inches of rain fell in 6.5 hours.
Montpelier, ID (1990)
75 mph winds gust; tree damage.