Today's topics: Phony autumn, busy tropics

It really seemed like autumn arrived in the Charlotte region today, with the morning low dropping to 59 degrees, and temperatures only recovering into the lower 70s by mid-afternoon.

Cool weather is expected to continue for several days, with highs near 80 and lows in the upper 50s. And it's a dry air mass, not the artificially-cooled situations we sometimes get when the humidity is sky-high and the only reason why temperatures have dropped is because of thick clouds.

No, this really is a taste of autumn, thanks to low pressure over the eastern United States that is dragging Canadian air southward.

But the computers say it won't last. Actually, we didn't need the computers. The calendar and common sense could have told us that.

It's September 7, and history shows there are still some hot days ahead. Sure enough, the latest computer models predict a return of much warmer conditions by next Tuesday. Highs in the middle of next week are predicted to be in the upper 80s to near 90 degrees. The computers show plenty of really warm weather into the last week of September, in fact.

So enjoy the next few days, and pretend that autumn has arrived. But when summer returns next week, you should be prepared.

Busy Tropics: As of 2:30 p.m. Wednesday, we have three systems in the Atlantic/Caribbean basin. Hurricane Katia is bound for the North Atlantic, never to bother a land mass in the Western Hemisphere. It was steered away from the United States by a low pressure trough over the East Coast -- as has been the case, in large part, for about three years.

The other two systems are Tropical Storm Maria, which is in the eastern Atlantic, and Invest 96F, a cluster of thunderstorms in the Bay of Campeche, off the Gulf of Mexico.

The computers haven't agreed on the future track of either system, but their paths might be related -- just as Tropical Storm Lee's northeast push pushed Katia away from the U.S. coast.

If 96F, which is expected to become a tropical storm soon, moves northward into the Gulf Coast, it would deepen the trough along the eastern United States shore and steer Maria away from the coast. That's what some computer models are predicting. By the way, that would leave open the possibility of 96F (which would be named Nate) copying Lee and bringing heavy storms into the western Carolinas.

But that's a long ways down the road.

Now, if 96F should move westward into Mexico (which is what most models forecast), then it leaves the door open for Maria to stay on a westerly track past the Caribbean islands and toward the Florida or Georgia coast.

The overwhelming trend this year -- and in 2008, 2009 and 2010 -- has been for Atlantic hurricanes to curve away from the Southeast coast. And that's probably what will happen with Maria.

But there are some interesting possibilities to watch in coming days.