In the year of unrelenting strangeness, the Philadelphia region finds itself under a flood threat from a storm named for a Greek letter.

After Hurricane Zeta makes a record-breaking landfall — probably along the Louisiana coast early Wednesday evening — its remnants are due to arc northeastward toward the Philadelphia region, and heavy rains are expected Thursday into Thursday night.

Rain potential from Zeta and its remnants.
National Hurricane Center
Rain potential from Zeta and its remnants.

The National Weather Service says flash flooding is possible with up to three inches of rain starting Thursday morning. If that much fell, some road-ponding would be a reasonably safe bet given all the drain-clogging leaf-fall.

In addition to clogging drains, wet leaves are “extremely slick,” said PennDot spokesperson Brad Rudolph, adding that crews would be out attempting to clear drains, especially along interstates.

Any downpours also could set off stream flooding. “That’s definitely a possibility,” Trent Davis, a meteorologist with the National Weather Service in Mount Holly, said Tuesday.

But some residents along the Gulf Coast evidently are in for a far rougher time of it. Hurricane warnings have been posted from Morgan City, La., to the Mississippi/Alabama border.

While Zeta lost its hurricane strength during its frictional encounter with the Yucatan landmass, Zeta lost its hurricane strength, but it was due to regain it with peak winds of 80 mph once it begins prowling the warm waters of the Gulf of Mexico.

Projected path of Zeta and its remnants.
National Hurricane Center
Projected path of Zeta and its remnants.

If the forecast holds, Zeta would be the record 11th tropical storm to make a U.S. landfall this season. The old standard, nine, had stood for more than a century.

It also would be the eighth to land on the Gulf shores this season. In contrast, the Atlantic Coast has seen only one hurricane make landfall.

This would be the third instance of tropical-storm remnants affecting the Philadelphia region. Fay and Isiais generated considerable rainfall around here during the summer.

Since then the procession of storms in the Atlantic Basin, which includes the Gulf of Mexico and the Caribbean Sea, has zipped through the National Hurricane Center’s naming alphabet, and the personifications have yielded to the letters of Greek alphabet.

If an “Eta” develops in the Atlantic Basin — don’t be confused by the “Z" in Zeta, that’s only the sixth letter of the Greek alphabet — it would be tropical storm No. 28, tying the record set in 2005, the only other season that made it to Alpha.

The average number for tropical storms, those with winds of at least 39 mph, in the June 1 to Nov. 30 season is 11. The normal for hurricanes, those with winds of 74 mph or better, is six; Zeta has become No. 11.

This would be the first time that Philadelphia experienced impacts from a Greek-letter storm.