Friday, October 26, 2012

Transitioning Tropical Topic

Sandy continues to experience some shear and has been showing some signs of transitioning away from a purely tropical system through the day today. It has 75 mph max winds this afternoon and is currently moving away from the Bahamas. We've been hitting the point for the past few days that it does not matter what the title is in front of Sandy -- tropical, nontropical, hybrid,'s a storm that's going to have a good deal of impact along the East Coast.

We're not talking about the storm to end all storms...we're not talking about the storm that will wipe Jersey or Delaware off the map, nor the storm that knocks Snooki off of her heals, but it will be a bad storm nonetheless.

You can see on visible satellite that dry air is starting to punch into the southern and eastern sides of the storm and that the core of thunderstorm activity is north of the center of circulation.  This is a sign that shear and dry air are beginning to make their mark on this storm as it moves farther north.  You can see the approaching cold front to Sandy's west and northwest -- that will provide the fuel to help reinvigorate the storm over the weekend.  I would not be surprised if Sandy "weakened" in wind strength somewhat due to the wind shear present before it intensifies somewhat later this weekend as it continues its transition towards nontropical status, intensifying due to interaction with that approaching trough, and acting very much like a large nor'easter with tropical energy fused into it.

Modeling continues to suggest a landfall point somewhere in the Mid Atlantic or in Southern New England -- the Euro did shift about 100 miles north with this afternoon's model run, bringing the center of the storm inland near Atlantic City.  The GFS is near Providence, RI with its landfall point.  We'll continue to see some nudging in timing/details/landfall points with the storm in the coming days but the whole of the Jersey and Delaware coastlines will be impacted by large surf, tidal flooding, and strong winds starting Sunday from south to north, with the worst of the worst occurring on Monday and Monday night...and if the GFS is right, into Tuesday.

Some points we continue to reiterate:

  • Impacts for all include rain and varying amounts of wind.  Wind will be stronger towards the Shore.  Rainfall could range between three and six inches, perhaps more in spots.
  • Worst impacts at the coastline depend on track of storm center.  If Sandy comes ashore near Delaware or Maryland, worst impacts will include the Jersey coastline, Delaware Bay, and Delaware. A landfall up into Rhode Island (the GFS scenario) would push the worst impacts towards New England.  Still would be some tidal flooding, some beach erosion, but not on the order of a center track to one's south or southwest.
  • Don't get hung up on the title of the storm or whether it's a hurricane, tropical storm, subtropical, or posttropical entity.  Sandy is a large storm and will have a large amount of impact along the East Coast on Monday and Tuesday.