10.29.12

Sandy Will Be Worse Than Irene

Posted in Commentary, Storm History, Storm Facts, Storm Preparation, Storm Safety, Hurricane Anomalies, Tracking the Tropics at 1:17 am by gmachos

Storm’s Track And Strength Much Different Than Irene Was

Hours away from what could be an historic landfall along the Jersey Shore, Hurricane Sandy is expected to be a devastating storm.  However, there are those around the Garden State and neighboring states that think it would be as bad.  They will ride it out just like they did with Irene.  There is just one problem with that, and that is Sandy is a much different animal than Irene was.

The storm’s track, size, momentum, and intensity is expected to be much different than Hurricane Irene was when it came up the coast.  Differences between the two storms range from minimum central pressure, storm surge levels, and maximum sustained winds.  Here is a breakdown of how Sandy is a much different threat than Irene.

Storm Track

Sandy’s projected track is going to be much different than Irene’s was.  Normally, tropical storms and hurricanes run along the East Coast of the United States, and don’t directly impact New Jersey.  Irene was a rare exception last year with two landfalls near Cape May and Little Egg Harbor.  However, the bulk of the Garden State remained on the western side of the storm, which is traditionally not as strong due to the counterclockwise flow around the low.  

Unfortunately, Sandy’s track will be much different and unprecedented, which could cause a lot of trouble.   Right now, Sandy is moving to the Northeast,  parallel to the Mid-Atlantic coast.  However, there is a blocking pattern in place with an area of high pressure to the northeast of Sandy, which will prevent it from escaping into the Atlantic.  On top of that, there is a cold front moving in from the west that will also pull the storm in.  In response, Sandy will make a left turn into the Jersey Shore anywhere from Toms River south to Atlantic City.

What this projected landfall along the Jersey Shore means is that a lot of the  Garden State including my hometown of South Plainfield in Middlesex County will face the storm’s notorious right front, or northeast quadrant.  This is the part of the storm that has the strongest winds and roughest weather.  

Storm Strength And Momentum

The strength of both Sandy and Irene are pretty much the same if you are looking at just the maximum sustained winds.  Irene ended up being a tropical storm upon landfall with 70 mile per hour winds.  Sandy currently has winds of 75 miles per hour, and could further strengthen to 80 mile per hour winds by landfall.  However, Sandy is a much deeper storm in the sense that its pressure is very low than a typical Category One Hurricane.  

Similar to Hurricane Isaac, which affected Louisiana back in August, Sandy is not your typical minimal hurricane with a minimum central pressure currently at 950 millibars, or 28.05 inches of Hg.   This is crucial because remember there is a high pressure system to the north, and that is creating a very strong pressure gradient with the hurricane.  A pressure gradient is a difference in pressure over a particular distance.  The pressure gradient will also add to the wind while the low pressure  itself will also help stir up the tide levels slightly.

Another difference between Sandy and Irene is the momentum each had prior to landfall.  If you recall, Irene limped her way to the finish line last August thanks to the entrainment of dry air into the system.  Irene was a ragged storm just hanging on to hurricane strength by the time it made land in Jersey. On the other hand, Sandy has been not only  able to maintain its strength, it has also been able to deepen with a drop of 10 millibars in pressure alone on Sunday.  It should be further energized when it moves across the Gulf Stream, and morphs into a hybrid storm as forecast.

Storm Size

Irene was a very large storm in its own right with tropical storm force winds stretching another 300 plus miles beyond the hurricane force winds.  Compared to Sandy though, it is much smaller storm.  As of the most recent advisory on Sunday night, Hurricane Sandy had hurricane force winds extending some 175 miles while tropical storm force winds extend some 520 miles.  

What that means is that Sandy is about 1,000 miles wide.  The storm is the second largest tropical cyclone in the Atlantic since 1988.  Hurricane Igor, which occurred during the 2010 Atlantic Hurricane Season,  is the largest in the last 25 years.  Hurricane Gilbert was the vast Atlantic storm in 1988 when it was as big as the state of Texas after making landfall in the Yucatan and coming ashore again near Matamoros, Mexico.

The size is important because that will play a role in determining the duration of the rough weather conditions.  It will also cover a broader area.  The entire state will feel winds of 60 to 80 miles per hour at the height of the storm.  Conditions will be felt as far west as Ohio and Indiana.  

One Final Note

Besides the heavy rain, wind, waves, and storm surge being stirred up in the Mid-Atlantic from the Delmarva to New England, this system will also be unique in the sense that it will help produce heavy snowfall in Southwestern Virginia, West Virginia, Eastern Tennesse, and Western North Carolina along the Appalachian Mountains.  In terms of its size, scope, power, and variety of weather, Sandy could equal and even surpass Superstorm ‘93.

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