Monday, October 29, 2012

High Wind Warning, Flood Watch for New England

There will be no Hurricane or Tropical Storm warning's for the northeast due to Sandy's transition into a Nor'Easter on steroids.  Once again we have to play mental games with a Hurricane because people here its a "weak category 1" and let their guard down.  First of all we don't get Category 1's in the northeast often.  Second of all the pressure in Sandy has dropped to 946 mb, consistent with a Category 3 Hurricane.  Sandy will not have a powerful core of winds around the center like a purely tropical system would.  Instead the wind field is incredibly large and so everyone feels the effects of the storm for over 24 hours.  A lashing like this will strip the trees that aren't knocked down and so our landscape will look like early December. 

Here is a timeline of what to expect, where, and when.

Today- Noon to Midnight
The heaviest winds will occur during this period.  In Southern New England we will get a strong band of winds by noon time lasting through the night.  Hurricane force gusts will be likely when the rain bands begin to move in around 4 or 5 PM.  It is during this period the majority of trees and powerlines will fall down.

For coastal residents the surge and waves are already inundating the coastline well away from the center.  The high tide this afternoon will be bad; the high tide tonight will be awful.  I expect serious flooding from Chatham to Delaware Bay.  Surge amounts may be to low.

Tomorrow Midnight to Noon
Tropical Storm force wind gusts continue well into tomorrow.  Expect wind gusts to 60 mph all the way to Detroit and Toronto.  See my other posts for graphics on this storm.  We were able to lock into a track on Saturday and we are right on track.

Ridiculously large wind field
From Dr, Ryan Maue of Weathberll Premium 
The pressure in this image is already incorrect- it shows 952 while Sandy is already down to 946 and falling.
Sheets and sheets of rain for the Mid Atlantic
The bands that will be affected Southern New England will not occur until this afternoon.  It is surprising some of the wind gusts reported thus far without any convection.

For example here is the predicted radar for today at 3 PM.
NAM Hi resolution 
And the winds at the same time
900 mb winds over hurricane force
We will be around 984 mb at this time, with 72 (kt) winds above.  When that convection taps those winds I expect wind gusts over 60 mph.  The closer to the coast the more likely these are to be 70 mph.

It is now likely that bands of showers and thunderstorms will continue to rotate onshore through tomorrow.  It will take a long time for power restoration efforts to begin.  Very concerned for the Mid Atlantic today as well as the Cape and coastal MA/RI.  Looking at the data this morning the surge along the eastern MA coast will be worse than forecast.  The waves on top of the surge will be many communities undoing from Sandy.

Follow me on twitter for information and photo's from the northeast. @zgreenwx






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