After highs in the 70s Thursday afternoon, Chicago is in for a cool down throughout the weekend.
Friday afternoon will bring a high of only 50 degrees with scattered clouds, before dropping down to the high 30s at night.
Saturday may creep down into the high 40s with even more clouds. The nighttime will bring temperatures to the high 30s.
Both days will be breezy, so those spending time outdoors should consider a light jacket. Precipitation is unlikely.
A stretch of higher-than-average temperatures will continue across a large portion of the Western U.S. this week.
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.
An El Nino-fueled October will feature more rainfall and storms for Southwest beginning this week.
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.
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.
Denver, CO (1982)
Wet snow - 6 inches foothills; slush in city. Power lines down, as well as trees.
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.