Early season nor’easter!!!

 Fall starts at 8:05 p.m. EDT this evening.

Sorry, this is so late....

Today

Much of the week ahead will be coolish and a bit unsettled for Pennsylvania and the Middle Atlatnic. but high pressure just to our north, looks to keep the northern part of the region mainly dry Wednesday and Thursday; all in all, it will be fairly nice fall weather. But that could change as we approach the weekend.

The week ahead

 The persistent northeast – east flow over the East Coast is going to push water into the coastal plain.  So, this will enhance high tides, and even low tides will see higher water levels than they would normally be. As the week goes on, all of this will build on itself leading to higher and higher water levels in the inlets, bays and sounds.

 

How the polar and subtropical jets interact will be very important to what happens this weekend! We have the upper-level low (ULL) over the Upper Great Lakes and developing low pressure off the Florida Coast.   The low over the Great Lakes is going to track south and east; the low off the Southeast Coast is going to track north and east. Both of these will end up interacting and develop a storm, off the Mid-Atlantic Coast. The timing of all of this will be the key in how strong the Coastal Storm gets.  We’ve been having shortwaves associated with the ULL in the Lakes track across Pennsylvania into the Mid-Atlantic, these also have their part to play in storm development. We also are going to have tropical moisture winging its way into the mix. This is a very complicated storm setup.

Because of the onshore flow, tidal flooding could start tomorrow for the Delmarva up through New Jersey. Thursday and Friday will see the coastal flooding risk increase, with New England dealing with coastal flooding over the Weekend.

We still have the two scenarios I talked about yesterday, #1 had the storm closer to the coast and then move toward the northern Mid-Atlantic Coast., resulting in a big impact storm. #2 had the storm staying a little farther east taking some of the heavy rain with it. Both scenarios have the coastal become cut-off and meander for a few days. Those looking for this to head out to sea, will be out of luck, as the block doesn’t allow for that to happen.

As the storm tracks northward, onshore winds and rain increase. Wind gust of 50-60 mph is possible, with gust of hurricane force possible for some along the coast. Along the coast, 1-2+ inches of rain is possible, with parts of southeast New England and closer to Boston seeing a chance for 3-4 inches of rain. Rain amounts will be falling off the farther north and west you go. This could keep part of eastern Pennsylvania into Central New York State on the fringe. The strength and position of high pressure over southern Canada, will have a big impact on the exact track and when this becomes cut-off, will determine who sees what.  Friday and the weekend will see a storm/nor’easter the only question is how strong it becomes.  The water off the Middle Atlantic and Southern New England Coast are abnormally warm. With this meandering around, there is a chance this becomes subtropical.

 

The Atlantic

Tropical Storm Fay has been downgraded to a tropical depression and has max sustained winds of 35mph, min central pressure is 1010mb. TD Fay is tracking southwest at 10mph. She ended up becoming the strongest Atlantic tropical cyclone this season with max sustained winds of around 70mph, But she is now in the process of dying over the open northeastern Atlantic.

 

We also have that tropical wave that is coming off of Africa. The NHC has the development odds for this at 30%. As it gets off the African Coast it should track northwest then north because of strong steering  winds.  Those in Europe should keep an eye on this.