An unusual landfall may occur this weekend along the Gulf Coast if Tropical Storm Nestor continues on its projected path.

Landfalls of hurricanes and tropical storms do not take place that often in the contiguous U.S. this late in the year. The last such storm to do so was hurricane Wilma in 2005.

Tropical Storm Nestor before is expected to make landfall in the Florida Panhandle on Saturday. This would be a noteworthy event since landfalls in the contiguous U.S. do not happen all that often after Oct. 15.

(MORE: Gulf Disturbance Forecast)

This is in part because tropical cyclone activity continues to decrease after mid-October. The peak of hurricane season is from late August through September.

Upper-level patterns also change as fall progresses. Cold fronts reach farther south and become more frequent, reducing the chance for any tropical systems that form to make landfall in the U.S.

Since 1966, there have been six hurricane landfalls in the U.S. (Gladys in 1968; Juan and Kate in 1985; Jerry in 1989; Irene in 1999 and Wilma in 2005) and two tropical storm landfalls (Gordon in 1994 and Mitch in 1998) on or after Oct. 15. Six of those landfall occurred in Florida.

The last hurricane that made landfall this late in the year in the continental U.S. was Wilma on Oct. 24, 2005. Wilma was a major hurricane, a Category 3, when it made landfall in southwestern Florida.

The storm had previously set a record for the lowest pressure in the Atlantic Basin when it was a Category 5 hurricane. Wilma was responsible for 5 deaths in Florida and $20 billion in damage.

Mitch was the last tropical storm to make landfall in the U.S. after Oct. 15, Phil Klotzbach, tropical scientist at Colorado State University noted. Mitch had been a Category 5 hurricane but made landfall in southwestern Florida as a tropical storm on Nov. 5, 1998. Mitch killed thousands in Central America. Mitch spawned tornadoes in Florida which injured 65 people and damaged or destroyed more than 600 homes.

Sandy and Ida are two other recent storms that struck the U.S. this late in the season, but they were no longer tropical cyclones at the time of landfall.

Hurricane Sandy made landfall near Brigantine, New Jersey, on Oct. 29, 2012, but was classified as a post-tropical cyclone by the National Hurricane Center. Hurricane Ida had also transitioned to an extratropical cyclone just before making landfall near Dauphin Island, Alabama on Nov. 10, 2009.

In October, tropical systems often form closer to the U.S., mainly in the western Caribbean Sea, eastern Gulf of Mexico or near the East Coast in the western Atlantic. On average, one hurricane forms every year in October, according to the National Hurricane Center.

It should be noted that big storms can and often do occur in October and November, but increasingly with less tropical characteristics.

(MORE: Here's Where the Hurricane Threat Is in October)

In November, one hurricane typical forms every three years in the Atlantic basin. The most likely area of development is in parts of the western and central Atlantic.

So although it is past the peak of hurricane season, tropical cyclones still develop this late in the season.

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