A major shift in the weather pattern will drive a blast of cool air southeastward from Canada across the Plains, Midwest, East and South into the weekend.
The blast of air from the Canada Prairies will drive temperatures and humidity levels down all the way to Texas and eventually much of the Atlantic Seaboard.
Temperatures may struggle to top 70 around Chicago both days of the weekend.
As the cooler air blasts across the warm waters of the Great Lakes, waterspouts are likely to spin up this weekend.
In Texas, the 100-degree heat from much of this summer will be replaced by highs in the 80s with much lower humidity in such cities as Dallas, San Angelo and Houston.
In the central and northern Appalachians, in the wake of the front which marks the leading edge of cooler air, the coolest spots could have highs near 60 on Sunday.
In the Deep South, for the folks who have been enduring tropical heat and humidity this week while cleaning up after Isaac, highs in the 80s with low humidity and sunshine will settle in later this weekend into next week.
While the magnitude of cooling will be less pronounced in much of the East's I-95 corridor, humidity levels will be shaved substantially and highs will be in the 70s by early next week from Boston to New York City and Washington, D.C.
The blast of cooler air and refreshing humidity will be preceded by rounds of showers and thunderstorms, which can lead to flash flooding and localized severe weather.
The downpours and severe weather will hit portions of the Midwest Friday then the Deep South and Atlantic coast into the weekend.
In addition, folks in portions of Florida may have to deal with a weak tropical system, such as a tropical depression or tropical storm and its torrential downpours this weekend. The feature could come about of a cluster of thunderstorms over the northern Gulf of Mexico, which are part of the old remains of Isaac.
As cooler air drives into the eastern U.S. this weekend, a compensating northerly flow over the Atlantic Ocean may help drive Hurricane Leslie into Atlantic Canada early next week.
A budding tropical disturbance has the potential to strengthen significantly and reach Florida with strong winds, coastal flooding and torrential rainfall during Sunday and Monday.
Rounds of showers and thunderstorms will bring the potential for flash flooding and localized damaging wind gusts through Thursday.
Stargazers will want to dig out their binoculars and telescopes this weekend as Venus and Jupiter shine so close that they appear as one large, bright star in the evening sky.
One final surge of heat will encompass much of England and Wales from Tuesday through Thursday.
Following a taste of autumn chill to start the week, is summer heat and humidity over for the northeastern United States?
The remains of Typhoon Holly brought heavy rains and flooding to south-central Alaska with heavy snow inland. (4-foot drifts at Denali National Park).
Hampton Roads, VA (1990)
Very heavy rain fell during the morning, causing widespread flooding. There was also 7.33 inches of rain at Virginia Beach. Between 4 and 5 inches of rain fell at Hampton Roads.
Cloudburst at Guinea, VA - 9.25 inches of rain in only 40 minutes.