Sandy…Big Impact Or A Few Waves

October 23rd, 2012 at 9:31 am by under Weather

There has been a lot of talk lately about tropical storm Sandy up and down the East Coast.  There are many long-term possibilities with the system but there are two main lines of thought.  More on that in a moment.  For now let’s talk about what’s going on in the short-term.  Sandy is a tropical storm and as of 8 am is moving to the north-northeast.  At the moment Sandy is in a region of warm water and lower wind shear.  Remember the stronger the wind shear (difference in the vertical winds from top to bottom), the more the tops of the thunderstorms can get sheared off.  Hence a weaker storm.  So for now rapid strengthening is forecast:

Areas Of Wind Shear (CIMSS)

In fact the latest forecast has Sandy becoming a hurricane in the next 36 hours before making landfall over Jamaica.  This will cause a lot of problems for that country.  Mostly with flooding from heavy rain.  After that it will push north and once again make landfall over eastern Cuba.  Officially it is forecast to be a weak hurricane at that point.  The higher elevations of Cuba should weaken the storm, so that it gets down to a tropical storm on the other side.  At that point it will trudge through the Bahamas.  To my knowledge a cruise ship just left Norfolk for that region.  I hope they fare well.  The wind shear should increase by the time it moves over Cuba.  It is possible that the storm could weaken even more than the models predict, but I doubt it will die out completely.

Forecast Of Sandy

From that point on the storm is expected to move to the north-northeast.  Here is where the models begin to disagree.  Some of the models…most of the models take the storm northeast towards Bermuda.  This includes the GFS model which has been consistent over the last 24 hours as well as the BAMs and now the Canadian.  That is important because the Canadian was one of the farthest west models just yesterday.  The Navy (NOGAPS) ((white line below)), and the European however run Sandy up closer to the coast.

Forecast Models

The farther north the storms get, the more they will interact with a cold front and become subtropical or even non-tropical.  The European and NOGAPS models basically turn the storm into a nor’easter, and move it offshore by a couple hundred miles. They also run it into the United States up towards Massachusetts.  There is even talk that there would be some snow in the mountainous areas up there in Vermont and New Hampshire.  It would be a very sizeable storm.  Locally if it did take that route we would expect some tidal flooding along the coast.  Minor…maybe moderate.  We would see heavy rain as the cold front gets hung up near here and the tropical moisture rides into it from the east.  We would also see some gusty winds, but the worst winds would be stay offshore.  Actually, the winds would pick up when it gets north of here in that scenario.  But…keep in mind this is just one scenario.  The bulk of the models run it more towards Bermuda.  In that case we would only see a few higher waves across the region.  We would still see a few scattered showers along the cold front, but nothing like we would see with the closer case.

What will probably happen will be that the bulk of the models will shift a little west, and the European and Navy model will shift a bit east.  It will probably be half-way between Bermuda and Hatteras.  We’ll be able to see the trend today, and which way the models shift.  However, we won’t really have a good handle on the exact forecast until it crosses Cuba.   We have plenty of time to prepare for any impacts from the storm.  If I lived around Hatteras, then I would be watching the forecast very closely for the next couple of days.

There is another depression (that’s right…another one!) out in the central Atlantic.  It is tropical depression #19, and had winds this morning of 35 miles per hour.  It will probably be tropical storm Tony by later today, but it is moving northeast and will not have any impacts on our local region.

Local weather is quiet and warm today. Highs will be in the upper 70s to low 80s with lots of sunshine and a southwest wind at 5-10.  Tomorrow we will be even warmer with highs in the low 80s and lot of sunshine.  A back-door cold front will move through late Thursday.  This will start cooling down our weather going into the weekend.

Meteorologist: Jeremy Wheeler

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