Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Posts: 2565
Loc: Melbourne, FL
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Hurricane Sandy - Postscript
Sun Oct 28 2012 02:14 PM
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SANDY - Postscript
There can be very little doubt that the name will be retired, but...
Was Sandy a Hurricane at landfall or not?
According to the NHC, it was not a hurricane at landfall:
"SURFACE...RADAR...AND AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT DATA INDICATE THAT POST-TROPICAL CYCLONE SANDY MADE LANDFALL NEAR ATLANTIC CITY NEW JERSEY AROUND 800 PM EDT...0000 UTC...WITH MAXIMUM SUSTAINED WINDS OF 80 MPH...130 KM/H."
But according to just about everybody else, it certainly was.
It seems like questionable judgement to change the classification an hour before landfall since NHC had already given responsibility to local weather service offices for watches/warnings, i.e., no bulletins would need to be changed:
'700 PM EDT MON OCT 29 2012
...SANDY BECOMES POST-TROPICAL...
...CENTER EXPECTED TO MAKE LANDFALL WITHIN THE NEXT HOUR OR SO..."
From the NHC Glossary:
"Post-tropical Cyclone:
A former tropical cyclone. This generic term describes a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can continue carrying heavy rains and high winds. Note that former tropical cyclones that have become fully extratropical...as well as remnant lows...are two classes of post-tropical cyclones."
Note that the description contradicts itself, i.e., "a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone" vs "former tropical cyclones that have become fully extratropical". So which is it !?
If there is indeed some 'wiggle' room to determine whether a cyclone is still tropical vs post-tropical (or vise versa) then why not less rigidity as to the proper time to change the classification - no matter what an earlier forecast might have indicated? Perhaps post-analysis (along with some good scientific discussion) will restore some clarification - certainly excellent Recon data was collected prior to landfall.
I'm sure that SANDY stands alone as the most damaging Cat I (Post-tropical) Hurricane in history.
ED
Original Blog on 10/28/12
At 28/15Z, Hurricane Sandy was located about 250 miles to the southeast of Cape Hatteras, North Carolina, moving to the northeast at about 12 knots. Maximum winds are still listed as 65 knots however these winds are located well to the west of the center and they are probably somewhat generous. Central pressure continues to fall - now at 951MB (28.08"). In the 'classic' sense, Sandy is developing into a hybrid system but it doesn't matter much in terms of weather impacts. Sandy should arc northeast, north and then northwest today and Monday with landfall likely along the central New Jersey coast on Long Beach around 5AM Tuesday morning. Winds of 50 knots or greater are likely from southern Long Island to southern Maryland with gusts at or near hurricane force. Winds likely to be onshore from Long Beach, New Jersey, northward to southern Cape Cod, Massachusetts with storm surge up to 6-8 feet from Long Beach New Jersey to Long Beach, New York. Tropical storm force winds likely over a large area from northern Virginia to western Pennsylvania to the southern half of New York and all of southern New England - to include Washington, D.C., New Jersey, Delaware and Maryland. Expect heavy rains, beach erosion, flooding of inland waterways, coastal flooding (especially at times of astronomical high tides) and widespread power outages.
Because of an expected transition of Sandy to a non-tropical storm prior to landfall, NHC has delegated watch/warning responsibilities to local NWS offices in the impact area. I am not sold on this approach and in their attempt to avoid confusion they may have created some. The implication is that there is only the potential for confusion when you go from a tropical system to a non-tropical system and not the other way around. The un-named system off Florida last October certainly caused considerable confusion. NHC needs to evaluate a different approach to public awareness regarding the landfall and area impacts of these transitional systems, however that is another topic for another time. You can read about their Sandy Transition Plan here:
NHC Sandy Transition Plan
ED
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