Snowflakes may accompany the coldest air so far this season in parts of the Midwest and Northeast U.S.
A cooldown with clouds, showers and thunderstorms is in store for Southern California and much of the Southwest following recent heat and sunshine.
A dominant storm track featuring storms moving west to east across Europe will result in a stark contrast between cold air building across Scandinavia and milder air masses entrenched near the Mediterranean.
After waves of cool air progress through the Midwest and Northeast this week, some areas will be cold enough for the first snow showers of the season by this weekend.
An effort is underway to fill a radar hole in Charlotte, North Carolina, and similarly populated areas in the United States to better detect and protect the public from severe weather.
Unmanned aerial vehicles (UAVs) interfered with containment efforts in the West on at least 25 occasions in 2015.
Newly formed Tropical Storm Koppu is on track to threaten the Philippines this weekend. Those in Taiwan and Japan should also monitor the storm for potential impacts next week.
While welcome rain and mountain snow sweeps across Chile, a potent midweek storm will threaten places from northern Argentina to southeastern Brazil with heavy rain and locally severe thunderstorms.
A "blob" of abnormally cold water in the North Atlantic, located near Greenland, has the potential to put enough drag on the ocean current to impact weather conditions in the years to come.
Tropical Storm Nora moved into to the Central Pacific Basin on Sunday, where unusually warm waters have already led to a record 13 tropical systems this hurricane season.
Winter will kick off with mild weather in the Northeast and mid-Atlantic as an intensifying El Nino influences the weather pattern across the country.
Early-season snows: Jay Peak 6 inches Warren 5 inches
New England (1990)
Remains of Tropical Storms Klaus and Marco brought torrential rains and flooding. Parts of Connecticut had 6 inches of rain or more. Stafford, CT, had 4.20 inches.
East Coast (1846)
Great Hurricane of 1846. Track: Cuba, Key West, FL; GA; Carolinas; Chesapeake Bay; PA - major damage all areas (Similar to Hazel in 1954). Lashed the Delaware River "into a perfect fury and its roar would have drowned out the thunder of the Niagara.