Hurricane Sandy - LIVE - Meteorological Discussion

[Scott747]

5 pm package brings it ashore across Spray Beach and just S of Stafford Township late Tuesday morning.

11 pm track shifts S to Sea Isle City -

[wxmeddler]

Dropsonde in "eye" had 5 kts at 700 mb but 35 kts at the surface with a 971mb. Me thinking definitely sheared.

[Roger Smith]

Just posted ominous look to RGEM 48h on other thread ... not surprised to see dip in intensity now, could recover a bit later Friday into Saturday but anyway it's all about the reality or not of the explosive deepening phase Sunday night into Monday that has dominated all models that explored a coastal landfalling track. Unless it falls below 70 knots between now and then more or less irrelevant to these vital landfall forecasts. The only wild card could be some sort of unexpected runaway intensification but doubt the global models of 2012 could all miss that. You do have to wonder what these models would be showing on the night of 9-19-1938.

[Jim Marusak]

Map I created using Digital Atmosphere. I can create it for any geographic domain.

can it also handle upper-air obs, like say the special 18z soundings nationwide that we're putting up in the US attm, or just surface?

[tmagan]

can it also handle upper-air obs, like say the special 18z soundings nationwide that we're putting up in the US attm, or just surface?

Yes

[tmagan]

06Z Observations

[phil882]

Per Recon and Satellite Imagery... sandy is now losing the tight inner core it had for the past 24 hours. The highest winds are now quite a ways away from the center and this trend should continue over the next 24-36 hours as the upper level potential vorticity wraps around the center and slowly fills as the anticyclonic flow associated with Sandy overcomes the upper level vortex.

Somebody mentioned that TCs don't absorb upper level lows. While thats not really an elegant way to explain the current configuration, strong tropical cyclones do often destroy upper level PV anomalies (ones associated with mid-latitude troughs) if SSTs underneath the circulations are sufficient to allow for continued convective development through diabetic processes. Sandy is a unique case because its divergent outflow associated with the storm is so large and so overpowering, the upper level low will likely be easily overcome as all of the numerical guidance suggests. Sandy has also maintained a gyre like structure, which has given it an unusually large cirrus canopy associated with convection as outer vorticity maxima continue to rotate around. Sandy, as the inner core weakens, will act as another vorticity maxima, rotating within the larger gyre.

[Roger Smith]

I notice the GGEM lost the plot and continued to take the storm northeast again. The Euro still looks ominous. We all need to realize that anything could happen in this scenario and the current status of the storm is not that strong a clue since no model anticipated anything different from this status at 06z Friday, now it may well eventuate that Chad Myers will seem to have over-reacted come Tuesday, or this may be forgotten in the wake of an unfolding disaster. Time will tell. I cannot see any other alternative than to convey a high risk of a major impact event but to add that nothing is settled yet. Let people make their own minds up from that realistic assessment.

[Jim Marusak]

Yes

good to know. one, i'll have to pick up that program. but 2, until i do, any way when the 06 sondes are out you could maybe get some UA plots to go along with the sfc, to see what's coming in? say 850, 500 and 300? thanks.

[Ed Lizard]

weakening, but still nice warm core.

000

URNT12 KNHC 260602

VORTEX DATA MESSAGE AL182012

A. 26/05:11:10Z

B. 25 deg 44 min N

076 deg 23 min W

C. 700 mb 2841 m

D. 60 kt

E. 046 deg 76 nm

F. 127 deg 75 kt

G. 047 deg 90 nm

H. 970 mb

I. 9 C / 3045 m

J. 18 C / 3047 m

K. 9 C / NA

L. NA

M. NA

N. 1345 / 7

O. 0.02 / 2 nm

P. AF305 0818A SANDY OB 16

MAX FL WIND 82 KT NE QUAD 04:33:30Z

;

[tmagan]

good to know. one, i'll have to pick up that program. but 2, until i do, any way when the 06 sondes are out you could maybe get some UA plots to go along with the sfc, to see what's coming in? say 850, 500 and 300? thanks.

06Z 850 mb Observations

06Z 500 mb Observations

06Z 300 mb Observations

[Jim Marusak]

wonder if they expected such high dew point depressions between the trough coming in from the west and the tropical system to the southeast. some of those are 30-40C on the 500 level in north florida and georgia in that ridge, and even 30+C DD's at 300 in SIL and TLH, even 15-25C at CHS and MHX. that's got to be aiding in maybe a bit of an earlier transition, or at least some of the spreading out with the wind fields.

[HurricaneJosh]

The 5 am EDT forecast has it at the coast near Ocean City/Rehoboth Beach at Day 4 as a 'cane, with winds of 70 kt. I remain very skeptical, honestly. I'm just having trouble picturing it-- especially at the end of October.

But it sure is interesting to think about. S NJ would get its heaviest hurricane hit of the century:

[Harry]

The 5 am EDT forecast has it at the coast near Ocean City/Rehoboth Beach at Day 4 as a 'cane, with winds of 70 kt. I remain very skeptical, honestly. I'm just having trouble picturing it-- especially at the end of October.

But it sure is interesting to think about. S NJ would get its heaviest hurricane hit of the century:

Unsure of how familiar you are with that area but If you are considering chasing this thing i would avoid most of the resorts there. Granted Rehoboth area is atleast somewhat easier to get out of if need be. It is not a barrier Island like a number of the others are like OC ( MD and NJ ), Wildwood, NJ, Bethany Beach DE/ Lewes DE, etc.. Most of them don't rise much above sea level either.

[HurricaneJosh]

Unsure of how familiar you are with that area but If you are considering chasing this thing i would avoid most of the resorts there. Granted Rehoboth area is atleast somewhat easier to get out of if need be. It is not a barrier Island like a number of the others are like OC ( MD and NJ ), Wildwood, NJ, Bethany Beach DE/ Lewes DE, etc.. Most of them don't rise much above sea level either.

Dude, if I chase it, I'm going to be very aggressive about it.

I've faced down majors alone in Mexico at night-- a transitioning Cat 1 in Jersey or Delaware ain't gonna make me blink, even.

P.S. I've been to Ocean City and Rehoboth Beach-- as a teenager.

[Harry]

Dude, if I chase it, I'm going to be very aggressive about it.

I've faced down majors alone in Mexico at night-- a transitioning Cat 1 in Jersey or Delaware ain't gonna make me blink, even.

P.S. I've been to Ocean City and Rehoboth Beach-- as a teenager.

Cool. I personally would not wanna be in Ocean City MD anyways. That big noreaster back in the 60s nearly ripped that place in half. It is a death trap imo. Same thing along that stretch from Ocean City MD to Dewey Beach DE.

Main issue is flooding ( coastal etc ) which is pretty bad even in weaker systems in that area.

Wish i could go visit my brother who has a place in Lewes DE. He is far enough in ( i think ) to avoid the flooding.

The winds would not bother me in the least bit. Just that flooding crap.

[thewxmann]

I can't see this having winds stronger than Cat 1. 930-940s is probably overdone, 950-970 sounds about right. Couple that with a really spread out storm, and this is a really strong noreaster with a tropical touch.

[dan11295]

Sandy is being sheared pretty badly now, would have to think the pressure would start rising more soon. Maybe this improved some after turning back to the NE? Right now the center is basically exposed.

[DaculaWeather]

I can't see this having winds stronger than Cat 1. 930-940s is probably overdone, 950-970 sounds about right. Couple that with a really spread out storm, and this is a really strong noreaster with a tropical touch.

I think you might be under estimating the baroclinic interaction that's going to take place.

[dan11295]

000

URNT12 KWBC 261002

VORTEX DATA MESSAGE AL182012

A. 26/09:25:26Z

B. 26 deg 08 min N

076 deg 44 min W

C. NA

D. NA

E. NA

F. 040 deg 82 kt

G. 322 deg 59 nm

H. 971 mb

I. 11 C / 2444 m

J. 18 C / 2441 m

K. 15 C / NA

L. NA

M. NA

N. 1345 / NA

O. 1 / 1

P. NOAA2 0918A SANDY OB 04

MAX FL WIND 82 KT NW QUAD 09:09:10Z

SONDE SPLASH WIND 18 KTS

CENTER SST 27.4C

Latest VDM Pressure fairly steady despite the shear and terrble presentation. The center is practically exposed at this point.

[Superstorm93]

Extra-tropical transition has begun to some extent.

Everything looks status-quo.

Sent from Tapatalk

[dan11295]

000

URNT12 KWBC 261111 CCA

VORTEX DATA MESSAGE AL182012

A. 26/10:52:37Z

B. 26 deg 13 min N

076 deg 48 min W

C. 700 mb 2906 m

D. 51 kt

E. 040 deg 101 nm

F. 117 deg 55 kt

G. 038 deg 52 nm

H. EXTRAP 974

I. 15 C / 2424 m

J. 20 C /2434 m

K. 14 / NA

L. NA

M. NA

N. 134/ NA

O. 1 / 1

P. NOAA2 0918A SANDY OB 11 CCA

MAX FL WIND 82 KT NW QUAD 09:09:10Z

SLP EXTRAP FROM 8000 ft

MAX FL TEMP 20 C 042 / 21 NM FROM FL CNTR

if pressure is accurate would imply clear weakening, short term at least, dont know how much impacts things down the road though.

[Srain]

HPC discussion this morning covers well the very concerns that Wes, Adam and Scott mentioned last evening during the radio broadcast regarding Storm Surge, Coastal Flooding/Fresh Water Flooding issues...

PRELIMINARY EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD

436 AM EDT FRI OCT 26 2012

VALID 12Z TUE OCT 30 2012 - 12Z FRI NOV 02 2012

...HURRICANE/POST-TROPICAL CYCLONE SANDY IS LIKELY TO SPREAD HIGH

WINDS/HEAVY RAINS/HEAVY MOUNTAIN SNOWS FROM THE CAROLINAS AND

CENTRAL APPALACHIANS NORTHWARD INTO CANADA...

GENERAL FLOW PATTERN

====================

A RETROGRADING POSITIVE ANOMALY MOVING FROM SOUTHERN GREENLAND

INTO NORTHERN QUEBEC FAVORS A QUASI-STATIONARY DEEP CYCLONE NEAR

THE NORTHEAST, IN THIS CASE HURRICANE SANDY AND ITS POST-TROPICAL

REMAINS. OTHERWISE...RIDGING IS GENERAL EXPECTED OUT

WEST...THOUGH QUASI-ZONAL FLOW ACROSS THE PACIFIC IS EXPECTED TO

SEND ENERGY ACROSS THE NORTHWEST. THE GUIDANCE IS IN EXCELLENT

AGREEMENT ON THE GENERAL FLOW PATTERN, THOUGH LARGE DETAIL ISSUES

REMAIN WITH SANDY'S FUTURE COURSE AND STRENGTH, KEEPING CERTAINTY

IN THE PATTERN ACROSS THE NORTHEAST BELOW AVERAGE.

MODEL PREFERENCE

================

THE NATIONAL HURRICANE CENTER (NHC) TRACK BEST RESEMBLES A

40/20/20/20 BLEND OF THE 12Z ECMWF ENSEMBLE MEAN/00Z ECMWF/00Z

GFS/00Z UKMET, WHICH WAS USED FOR MONDAY THROUGH WEDNESDAY. FOR

THURSDAY AND NEXT FRIDAY, TRANSITIONED TO A 00Z GFS/00Z ECMWF

COMPROMISE AS THEIR SOLUTIONS WITH SANDY CONVERGE. THE

EXTRATROPICAL TRANSITION OF SANDY MAY HAVE ALREADY BEGUN BASED

UPON RECENT SATELLITE IMAGERY...A PROCESS EXPECTED TO COMPLETE

BETWEEN TUESDAY AND WEDNESDAY PER NHC. THE DETERMINISTIC GUIDANCE

(PARTICULARLY THE 00Z ECMWF) SHOW PRESSURE SOLUTIONS WELL BEYOND

WHAT HAS EVER BEEN OBSERVED NEAR THE NEW JERSEY/NEW YORK COAST

(EVEN EXCEEDING THE 1938 LONG ISLAND EXPRESS HURRICANE) EARLY IN

THE MEDIUM RANGE PERIOD. THE DETERMINISTIC GUIDANCE (CANADIAN,

GFS, AND ECMWF INCLUDED) HAS SHOWN A VERY STRONG BIAS WITH

TROPICAL CYCLONES GAINING LATITUDE AND/OR TRANSITIONING INTO

NON-TROPICAL STORMS OVER THE PAST COUPLE YEARS, INCLUDING (BUT NOT

EXCLUSIVE TO) LESLIE 2012, ISAAC 2012, DEBBY 2012 IN THE WESTERN

SUBTROPICAL ATLANTIC, IRENE 2011, AND IGOR 2010. EVEN THE

PERFECT/HALLOWEEN STORM OF 1991 "ONLY" BOTTOMED OUT AT 972 HPA,

AND THIS FORECAST WAS ALLOWED TO EXCEED THAT SYSTEM WITHOUT GOING

OVERBOARD. PRESSURES FOR THE STORM WERE CAPPED AROUND 965 HPA

EARLY IN THE PERIOD PRIOR TO LANDFALL, AND ALLOWED TO WEAKEN ONCE

INLAND. THIS WAS COORDINATED WITH THE OCEAN PREDICTION CENTER

(OPC) AND IS CLOSE TO THE PAST COUPLE DAYS OF HPC/OPC CONTINUITY.

KEEP IN MIND THIS PREFERENCE WOULD INDICATE THAT THE MODEL-DERIVED

QPFS FOR THE GUIDANCE SHOWING CENTRAL PRESSURES UNDER 965 HPA ARE

LIKELY TOO EXCESSIVE DUE TO THEIR EXTREME LOW PRESSURE SOLUTIONS

FOR SANDY.

WEATHER IMPACTS

===============

PER THIS SOLUTION, FROM SUNDAY THROUGH WEDNESDAY, WINDS NEAR

HURRICANE-FORCE ARE EXPECTED TO LASH EXPOSED AREAS OF THE

NORTHEAST/MID-ATLANTIC STATES (THE COAST AND TOPOGRAPHY), LEADING

TO POTENTIALLY SERIOUS COASTAL EROSION AND COASTAL FLOODING. THE

TIMING OF THE FULL MOON AND THE BUILD-UP OF TIDES OVER MULTIPLE

TIDAL CYCLES SHOULD EXACERBATE THE SITUATION ALONG THE COAST,

PARTICULARLY IN CORNERS SUCH AS THE NEW YORK BIGHT. HEAVY RAINS

ARE EXPECTED TO FOCUS WITHIN SANDY'S WARM CONVEYOR BELT

CIRCULATION AS WELL AS ALONG ITS DRAPING WARM FRONT FROM THE

NORTHERN MID-ATLANTIC STATES INTO EASTERN CANADA, WITH LOCAL

AMOUNTS EXCEEDING 10 INCHES POSSIBLE. THIS SOLUTION WOULD ALLOW

SIGNIFICANT SNOWS WITHIN ITS COMMA HEAD PATTERN TO FALL ACROSS THE

MOUNTAINS OF WEST VIRGINIA/WESTERN PENNSYLVANIA/EASTERN OHIO;

LIKELY NOT TO THE EXTREME DEGREE SEEN WITHIN ANY OF THE CURRENT

DETERMINISTIC GUIDANCE. LAKE EFFECT SNOWS ACROSS THE EASTERN

GREAT LAKES ARE POSSIBLE THROUGH THE PERIOD WITHIN THE CYCLONIC

FLOW IN THE SYSTEM'S COLD SECTOR. AS THE CYCLONE WEAKENS AS IT

PULLS NORTHWARD THURSDAY INTO NEXT FRIDAY, WINDS SHOULD SLACKEN AS

SHOULD PRECIPITATION AMOUNTS/COVERAGE ACROSS THE NORTHEAST.

ROTH

[turtlehurricane]

If the models are right about this scenario the fireworks should start today, with things really getting going tonight as the sub-tropical jet and polar jet come together.

[Srain]

[tmagan]

12Z Observations

[Eskimo Joe]

From NHC:

000

URNT12 KNHC 261151

VORTEX DATA MESSAGE AL182012

A. 26/11:37:10Z

B. 26 deg 20 min N

076 deg 52 min W

C. 700 mb 2830 m

D. 76 kt

E. 238 deg 40 nm

F. 312 deg 64 kt

G. 238 deg 38 nm

H. 971 mb

I. 10 C / 3117 m

J. 16 C / 3110 m

K. 11 C / NA

L. NA

M. NA

N. 12345 / 7

O. 0.02 / 3 nm

P. AF309 1018A SANDY OB 05

MAX FL WIND 64 KT SW QUAD 11:26:30Z

Strong sfc winds near convective band over Great Abaco Island.

;

[Guest Imperator]

Is it me or does it look rather messy?

[DaculaWeather]

120 miles east of Cape Canaveral

Station 41010

NDBC

Location: 28.906N 78.471W

Date: Fri, 26 Oct 2012 12:20:00 UTC

Winds: NE (50°) at 33.0 kt gusting to 38.9 kt

Significant Wave Height: 24.3 ft

Dominant Wave Period: 13 sec

Atmospheric Pressure: 29.58 in

Air Temperature: 74.3 F

Water Temperature: 80.8 F

[Srain]

Is it me or does it look rather messy?

The transition has to extra tropical is underway. Sandy is still a formidable cyclone and the 'appearance' will likely be rather impressive over the next several days. Gale force winds extend well away from the center will expand in the days ahead.