Nor'easter to Impact the East Coast for Much of the Week

A nor'easter is developing off the coast of North Carolina along the strong cold front that pushed through yesterday. It's the same front producing heavy rain across extreme South Florida. The rain should finally slide off the tip of the peninsula late today.

A combination of the lowering pressure offshore and a strong high-pressure system over the Midwest is squeezing the air, creating strong winds from the northeast from North Carolina to New Jersey. The forecast is daunting for the affected coastal sections. The nor'easter is forecast to strengthen and stall or drift, maintaining the strong onshore winds through multiple high tide cycles.

Thankfully, the storm has formed far enough offshore that the impacts aren't worse. Assuming it doesn't drift closer to the coast – and the consensus of the computer forecasts is that it won't – the worst of the wind and rain will stay offshore. The pounding waves and extra-high tides will be the key impacts.

The storm is forecast to peak in strength about late Tuesday but still influence the weather until Thursday. That means that seawater that's pushed in to inlets and bays will not be able to drain out because of the onshore push of the relentless wind.

Coastal flood warnings and advisories are in effect along the coastline. Everyone along and near the coast from Long Island, New York, to North Carolina should stay aware of the latest forecast for their area.

COULD IT TURN TROPICAL?

The National Hurricane Center is drawing a low odds potential development area off the Mid-Atlantic coast. There is plenty of extra-warm ocean plus the Gulf Stream in the part of the Atlantic where the nor'easter has formed. The storm is forecast to track over the warm ocean while it's drifting around, so there's a chance that the fronts will dissipate, and the nor'easter will morph into a subtropical storm – a storm that develops a core circulation and has shed its fronts. If it managed that, it would get the name Josephine.

The NHC has zero odds for the next few days and then low odds for the rest of the week that that transition might happen.

The messaging with this kind of situation is annoying and potentially confusing because whether it technically remains a nor'easter or meteorologically transitions into Subtropical Storm Josephine, the impacts along the coast will be the same. The only change would be that a named storm gets listed in the record book.

The transition to a subtropical storm would most likely not occur until maybe Wednesday when the system will be slowly heading out to sea. So the technical transition is unlikely to be meaningful in terms of impact.

The system is stalled because a strong blocking pattern has developed over the Atlantic. That means the typical west-to-east movement of weather systems is drastically slowed. About Thursday, it looks like that pattern will finally break down.

IN THE PACIFIC NEAR MEXICO

Hurricane Trudy will make its closest approach to west-central Mexico today. The coastline between Manzanillo and Puerto Vallarta, which has been pummeled this year, is being impacted again by Trudy's outer bands. Fortunately, it appears the worst of the winds will stay offshore, but the interaction of the moisture and the mountains will produce dangerous conditions.

The National Hurricane Center forecast calls for Trudy to move away from the coast tomorrow and die out south of Cabo San Lucas.

South of Trudy, a system that is likely to eventually be named Vance is expected to form. It will slowly track north well offshore of the Mexican coast, but eventual impacts can't be ruled out.