As of 11pm EDT on Friday, Hurricane Sandy has wind of 75 mph and has a forward speed slowed to 7 mph to the north. For what it is worth, that is not the most important point as it is already losing tropical characteristics. What makes this ‘The Perfect Storm’ is the influence of arctic air from the west and a blocking High Pressure system in New England helping to steer the storm into the Mid Atlantic.
See the new 3-day satellite loop showing the organization of Sandy in the Caribbean plus a developing cold core storm in the north Atlantic that is part of the blocking pattern.
The latest tropical computer models appear to have once again converged on the Mid Atlantic, mostly north of Ocean City and pointing toward the DE Bay. I want to stress again that hugging one model over another can be limiting in a forecast. As we have seen often, this time as well, they can meander and flip flop on tracks. Pinning a direct landfall is impossible now, but picking a region is the best bet. I will be looking for the intensity developing on Sunday as the cold air presses closer and the increased force on the storm will force it to intensify again. Once it passes the location of longitude 72W, that is when the storm should make the turn. Depending on how fast and how strong it develops, will determine the rest. A stronger storm will pull west sooner for more of a direct hit on the Delmarva or New Jersey. Slightly weaker and the storm will take the larger loop track to the north first. Until then, the rest is purely speculation.
What to look for:
What we all will be watching is Sandy transforming into a hybrid storm. That is when a hurricane can lose tropical characteristics as colder air enters the system. In this case, the entire jet stream will buckle and force a strong pressure gradient expanding the winds from just around the storm to reach out 1000 miles away. That is more common than you might imagine with a storm along the coast interacts with a cold front. This time, a strong blocking High Pressure in New England will add another force and prevent the storm form going out to sea. It not only will increase the intensity and drive it onto the east coast, but it may stall there for a few days.
There are still the same two ideas for the landfall. Either it loops out northeast near Boston then pulls westward to New York City and continues to slip southwest until settling in southern PA for a day or two. The loop idea, essentially the GFS model, is what I had bought into based on a weaker Sandy staying a little farther east, and slower redevelopment as a hybrid storm.
The long standing European Model does account for the weaker Sandy for now, which swings it farther east as well, before pulling it back west with a more direct hit on New Jersey. That is due to a faster redevelopment in the transition to a hybrid storm.
The problem is that both of these set ups would be utterly destructive to New York City and the metro area coast. The storm surge would funnel water along the coastline, which meets almost at a right angle by New York City. This shape of the coast would enhance the large ocean flow and would inundate Manhattan as it forces water into subway, tunnels, and the incredible underground infrastructure. This may alleviate the pressure of any water up the Chesapeake Bay or Delaware Bay, but those regions would be part of the large wind field of the storm. It also allows the arctic air to spill in from the west and bring a snowstorm into the mountains of western MD and WV. The high elevations such as Snowshoe, WV, which sits at 4848’, could measure a few feet of snow.
Below is a comment I posted on my Facebook page, so forgive me if this is a repeat for you. I thought it was important to pass along farther:
In response to a question about Derecho in June? That lasted 10-20 minutes. This will impact a much broader area for a few days. So if you are making a comparison, this will be worse.
About Storm Surge:
This is all dependent on the exact track of the storm. The general rule is the right front side of the storm with respect to landfall will have the wind and water pushing onto land. The left side has the wind blowing away from land counteracting the effect and diminishing the push of water.
Any landfall north of VA Beach would spare a surge up the Bay… Even OC… But possibly a surge for DE Bay. The Euro takes the storm now near Atlantic City. The surge would still end up NORTH of the center. That is NJ and metro NYC. UGH! The GFS has a wider loop swinging south of Boston, along long Island and west into NYC= UGH! Both with major storm surge. Not because of category storm, but the combo of wave energy built up, momentum in that direction, and the massive size as this spreads out by Mon/Tues. I am still with thinking winds will be sustained at 50 mph+. The worst day will be Tuesday, but increasing Monday, it could last a few days as the storm with either set up is expected to wonder or stall in southern PA.
This deep pressure with this size, and this trajectory has NEVER happened in our lifetimes. This is unchartered territory so all of these are expectations, but I expect to be surprised too. I am being honest. I don’t know it all and I don’t claim to. All I can do is call it like I see it and bear witness like the rest of us. Don’t claim it is judgment day. Just a special storm that I remember theorizing in school. We believe it has happened before. The shape of the coastline from Long Island down the Delmarva suggests it. It is just now that we get to see it. By the way, have any of you seen the TV show Revolution? The power outages from Isabel and Irene may be much more widespread this time. That could make it last much longer. I’d prefer it not be here too, but that is hard to rule out completely.
I will monitor that part of the storm on my Baltimore Weather Examiner page. Also follow along for updates through:
Facebook: Justin Berk, Meteorologist
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A TROPICAL STORM WARNING IS IN EFFECT FOR…
* FLORIDA EAST COAST FROM NORTH OF JUPITER INLET TO ST AUGUSTINE
* SOUTH SANTEE RIVER TO DUCK…INCLUDING PAMLICO
AND ALBEMARLE SOUNDS
* GREAT ABACO AND GRAND BAHAMA ISLANDS
A TROPICAL STORM WATCH IS IN EFFECT FOR…
* SAVANNAH RIVER TO SOUTH SANTEE RIVER
* FLORIDA EAST COAST FROM NORTH OF ST AUGUSTINE TO FERNANDINA BEACH
Tropical storm and hurricane history of naming. 2012 Atlantic list
Tropical Storm formation history: Storm origin maps every 10 days of season
Hurricane Preparedness Week: Storm Surge is the most deadly and destructive
Hurricane Destruction Animation based on Saffir Simpson Scale
NASA Global Hawk: Hurricane drone planes run by locals at Goddard