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Potential major phasing event this weekend


forkyfork

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way too early to nail down specifics, if it keeps trending south on the Euro the winds may be much less.

As you may remember, the oeprational ECMWF was too far west with Irene at times. I expect it to eventually trend back east a little, which would put the NJ coast, NYC and Long Island more in the crosshairs.

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Roger,

If Sandy is post-tropical or, more likely transitioning, it probably wouldn't have a well-defined calm center.

FWIW, my thoughts are that Sandy's windfield will likely be expanding as it approaches landfall (perhaps in the Mid-Atlantic or New England with a rough guess that something between the Operational ECMWF and ECMWF/GFS ensemble mean might illustrate the area at greatest risk for landfall). It could still produce some very strong gusts and an impressive storm surge that could produce flooding along the Delmarva to Long Island. While it's too soon for me to speculate on its exact strength, I do think it's reasonable to state that Sandy would be more than one's typical nor'easter, but it very likely won't be another 1821 Hurricane, 1938 Hurricane or Hazel.

There remains a small probability that Sandy could escape in a fashion shown on some earlier runs of the GFS, but I think that's not very likely given that a lot would have to happen in the face of the current blocking for such an escape (a near "thread-the-needle"-type scenario).

Of course, many questions remain: How strong will Sandy be when it begins to interact with the trough? Will it fully or partially phase? Will baroclinic deepening occur? Will Sandy be post-tropical or transitioning? Where will she come ashore and at what trajectory?

I am sure no one is expecting that but is something similar to December 1992 wind strength wise and potentially damage wise more of a fair comparison? (I do understand that this is much different as December 1992 was not a hurricane when it originally developed)

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The major, overriding concern is the flooding as others have said. Cat 1 winds can cause severe wind damage (winds would likely be strongest near the immediate shore), but the flooding/surge is what everyone will really be honing in on. I would have to believe evacuations would be needed in low-lying areas if a Euro track verified. Another big concern I have is people not taking it seriously due to the word "nor'easter" being used in the media. I'm really hoping the NHC will maintain advisories on this, otherwise I get the sense people will just laugh this off. We really lucked out with Irene weakening the way it did, otherwise a lot of lives could have been lost due to people not taking Irene very seriously either, and that was a storm hitting at astronomical high tide, at high tide during the day. There's definitely a sense of complacency here and "how bad could this really be?"

As for the Euro being too far south for the worst effects here, keep in mind the huge pressure gradient that will exist for hundreds of miles north of the storm. Very strong winds will be a likelihood far away from the center under such a setup. Surge/flooding will be a threat for several high tide cycles due to the piling of water. It won't just be 1 or 2 high tides. What we want (for a lesser impact) is a setup where the low hits SE NE and retrogrades west. We would likely see more rain that way being on the west side, but the winds would be offshore and more in the 40-50 mph range rather than possibly 70-80 mph+ onshore. This kind of storm is so rare that it's hard to really pin down specific impacts.

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Bill, is Upton going to give out advisories or will the NHC do the job? I can see either one giving out advisories.

I don't know. Have feared a scenario like this for a long time. If NHC were to pass the hot potato to the WFOs on a system like this, it could send the wrong message to people in harm's way, even if it were a scientifically accurate decision (which can always be corrected in post-analysis anyway).

NHC track just SE of NYC at hr 120.

WOW.

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I don't know. Have feared a scenario like this for a long time. If NHC were to pass the hot potato to the WFOs on a system like this, it could send the wrong message to people in harm's way, even if it were a scientifically accurate decision (which can always be corrected in post-analysis anyway).

WOW.

I would hope NHC at least keeps it subtropical and keeps warnings up, for that very reason... because if not, people might let their guard down.

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I would hope NHC at least keeps it subtropical and keeps warnings up, for that very reason... because if not, people might let their guard down.

I'm already wary of the term "noreaster" being used in the media around here. This won't be a typical nor'easter, and people won't take it seriously. Really hoping they continue advisories, for the simple purpose of conveying the threat.

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I don't know. Have feared a scenario like this for a long time. If NHC were to pass the hot potato to the WFOs on a system like this, it could send the wrong message to people in harm's way, even if it were a scientifically accurate decision (which can always be corrected in post-analysis anyway).

WOW.

Thats a horrible track for the battery in lower manhnattan -a slow moving system

with a small storm surge funneling water , in conjunction with high tide into the same area

for an extended period of time one would have to be fearful of some sea water getting into the subway system and basements in lower manhattan . talk about a billion dollar pre election disaster . Lets hope it doesnt happen .

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what this in reality is the perfect storm making landfall..scary when you think about it

See this is what I am trying to assess. Is it fair to say that this has the potential to be a mimic of the Perfect Storm's dynamics (which who knows what that would do to land and lord help us all if it hits land) or would it be more like December 1992 just from the standpoint of damage and wind strengh as clearly December 1992 never began as a Hurricane?

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I am sure no one is expecting that but is something similar to December 1992 wind strength wise and potentially damage wise more of a fair comparison? (I do understand that this is much different as December 1992 was not a hurricane when it originally developed)

December 1992 is a good comparison in terms of wind and coastal flooding impacts, IMO.

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WTNT43 KNHC 251446

TCDAT3

HURRICANE SANDY DISCUSSION NUMBER 13

NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012

1100 AM EDT THU OCT 25 2012

THE SATELLITE PRESENTATION OF SANDY HAS BECOME A LITTLE LESS

IMPRESSIVE AFTER MOVING OVER EASTERN CUBA. THE EYE IS NO LONGER

APPARENT IN IMAGERY OR IN OBSERVATIONS FROM THE AIRCRAFT...AND THE

CDO HAS BECOME SOMEWHAT DISRUPTED ON THE WESTERN SIDE BY

SOUTHWESTERLY FLOW FROM AN UPPER-LEVEL LOW TO THE WEST. HOWEVER...

AIRCRAFT DATA INDICATE THAT THE CIRCULATION ASSOCIATED WITH SANDY

REMAINS QUITE STRONG...WITH A PEAK FLIGHT-LEVEL WIND AT 700 MB OF

126 KT AND A CENTRAL PRESSURE OF 964 MB. DATA FROM THE SFMR AND

DROPSONDES SUGGEST THAT THE WINDS FROM FLIGHT LEVEL ARE NOT

CURRENTLY MIXING DOWN TO THE SURFACE AT THE TYPICAL RATIO...SO A

BLEND OF THE DATA SUPPORT MAINTAINING AN INTENSITY OF 90 KT FOR THIS

ADVISORY. A CONTINUED INCREASE IN SHEAR AND INTERACTION WITH THE

UPPER-LEVEL LOW SHOULD RESULT IN GRADUAL WEAKENING DURING THE NEXT

COUPLE OF DAYS. HOWEVER...DURING THIS TIME THE OUTER WIND FIELD OF

SANDY IS EXPECTED TO EXPAND...AND SANDY IS FORECAST TO BE A LARGE

CYCLONE AT OR NEAR HURRICANE INTENSITY THROUGH THE END OF THE

FORECAST PERIOD.

THE INITIAL MOTION ESTIMATE IS 360/14...AFTER A BIT OF A JOG TO THE

RIGHT EARLIER THIS MORNING. THE REASONING FOR THE SHORT-TERM

PORTION OF THE TRACK FORECAST REMAINS UNCHANGED. SANDY SHOULD MOVE

NORTHWARD TODAY AND SLOW DOWN AS IT TURNS NORTH-NORTHWESTWARD ON

FRIDAY WHEN IT INTERACTS WITH THE AFOREMENTIONED UPPER-LEVEL LOW.

SANDY SHOULD THEN TURN NORTH-NORTHEASTWARD BY 72 HOURS AHEAD OF A

LONGWAVE TROUGH MOVING THROUGH THE EASTERN UNITED STATES. AFTER

THAT TIME...THE TRACK MODEL GUIDANCE CONTINUES TO TREND TOWARD A

NORTHWESTWARD TURN AS SANDY INTERACTS WITH AN AMPLIFYING SHORTWAVE

TROUGH OVER THE MID-ATLANTIC STATES. HOWEVER...THERE REMAIN

SIGNIFICANT DETAIL DIFFERENCES IN REGARD TO THE TIMING OF THIS

INTERACTION AND WHERE THE NORTHWEST TURN WILL OCCUR. THE ECMWF AND

GFDL MODELS SHOW A QUICKER TURN...BRINGING THE CENTER INLAND BY DAY

5. MUCH OF THE REST OF THE GUIDANCE SUGGESTS A MORE GRADUAL TURN

WITH THE CENTER STILL OFFSHORE AT 120 HOURS. THE NHC FORECAST HAS

BEEN SHIFTED WESTWARD AT DAYS 4 AND 5 AND LIES ABOUT HALFWAY

BETWEEN THE ECMWF AND THE GFS ENSEMBLE MEAN AND CLOSE TO THE ECMWF

ENSEMBLE MEAN. REGARDLESS OF THE EXACT TRACK OF SANDY...IT

IS LIKELY THAT SIGNIFICANT IMPACTS WILL BE FELT OVER PORTIONS OF

THE U.S. EAST COAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.

NOTE THAT THE TROPICAL CYCLONE WIND SPEED PROBABILITIES ARE NOT

DESIGNED TO HANDLE THE TYPE OF STRUCTURAL CHANGES ANTICIPATED WITH

SANDY DURING THE FORECAST PERIOD. AS A RESULT...THESE PROBABILITIES

WILL UNDERESTIMATE THE ACTUAL RISK OF STRONG WINDS AWAY FROM THE

CENTER OF SANDY.

FORECAST POSITIONS AND MAX WINDS

INIT 25/1500Z 22.4N 75.5W 90 KT 105 MPH

12H 26/0000Z 24.4N 75.6W 90 KT 105 MPH

24H 26/1200Z 26.2N 76.4W 80 KT 90 MPH

36H 27/0000Z 27.4N 76.9W 75 KT 85 MPH

48H 27/1200Z 28.9N 76.3W 70 KT 80 MPH

72H 28/1200Z 32.0N 73.5W 65 KT 75 MPH

96H 29/1200Z 36.0N 72.0W 65 KT 75 MPH

120H 30/1200Z 39.5N 73.5W 60 KT 70 MPH...POST-TROPICAL

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Even if the winds were expected to drop down to 70 mph, I would have hurricane warnings up for the coastline

with enhanced attention to the surge threat over several high tide cycles. The public won't be able to grasp

terms like warm seclusions or hybrids. The tropical to post tropical concept would cause people to lower their

guard.

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Even if the winds were expected to drop down to 70 mph, I would have hurricane warnings up for the coastline

with enhanced attention to the surge threat over several high tide cycles. The public won't be able to grasp

terms like warm seclusions or hybrids.

I guess the main stream media folks can just refer to it as a Hurricane force wind warning. While the official term would be Hurricane warning (if the NHC was smart like you said they would post hurricane warnings even though it may be extratropical by then) the media folks can term it as the aforementioned because there is no doubt they will have to mention that it is no longer a hurricane when the time comes to report it that way.

If I was reporting on the TV I would say, "while this storm is no longer a Hurricane, Hurricane Warnings still remain for the entire area as sustained winds will come close to Hurricane force with higher gusts."

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I guess the main stream media folks can just refer to it as a Hurricane force wind warning. While the official term would be Hurricane warning (if the NHC was smart like you said they would post hurricane warnings even though it may be extratropical by then) the media folks can term it as the aforementioned because there is no doubt they will have to mention that it is no longer a hurricane when the time comes to report it that way.

If I was reporting on the TV I would say, "while this storm is no longer a Hurricane, Hurricane Warnings still remain for the entire area as sustained winds will come close to Hurricane force with higher gusts."

Only the NWS is allowed to use the term Hurricane Warning. They DO have a warning called "Inland Hurricane Force Wind Warning", however.

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