At 9-plus inches, Philly is a shower away from a November rain record

Already 2018 has become the fourth-wettest year on record in Philadelphia and is almost certain to become No. 2 by Dec. 31.

And with a chance of snow and/or rain showers on Friday, this has a shot at becoming the wettest November in the period of record, which dates to 1871.

"It's a very active storm pattern," said Carl Erickson, a meteorologist with AccuWeather Inc.

So far, 9.03 inches of precipitation — that includes a healthy dash of melted snow from Nov. 15 — has been measured by the automated observing system at Philadelphia International Airport.

The November record is a few drops away at 9.06 inches, set in 1972, the raining champ.

"It'll be close," said Alex Staarmann, meteorologist at the National Weather Service Office in Mount Holly.

Since the summer, storms have tapped into generous moisture supplies, but what has happened this month is quite different from what was going on in August.

Summer rains tend to be more random, and this year they targeted areas just to the north and west of the city, particularly Berks County. Reading had close to 15 inches in August.

In November, the rains have been more generously distributed as more-organized coastal storms, typical of late fall and winter when the temperature contrasts that drive storms are more pronounced, have succeeded the more-episodic rains of the warm seasons.

This month's rains might well have a connection with the burgeoning El Niño, the periodic anomalous warming in the tropical Pacific.

Sea surface temperatures out that way now are about 2.5 degrees Fahrenheit above normal over thousands of miles of ocean, according to the government's Climate Prediction Center.

Weather moves west to east, so what happens out there affects weather in the United States, particularly in winter. Two very wet Novembers, the aforementioned 1972's, and 1977's — 7.76 inches — preceded El Niño-influenced winters.

What this November's storminess bodes for the future of the planet or even the winter of 2018-19 is impossible to say. Erickson said the active pattern is likely to continue well into December, and the climate center agrees.

November 1977 was followed by Philadelphia's snowiest winter, at 54.9 inches, since the 55.4 inches of  1898-99. By the way, the precipitation total for November 1898 was 7.19 inches.

Conversely, the winter of 1972-73 remains the only winter in Philadelphia history with no measurable snow.