Hurricane Sandy - LIVE - Meteorological Discussion

[Cheeznado]

WSI RPM 944mb landfall in the Delaware Bay. WV gets clobbered with many feet of snow.

[LMolineuxLM1]

WSI RPM 944mb landfall in the Delaware Bay. WV gets clobbered with many feet of snow.

The most historic flooding in Philly, on this run.

[Cheeznado]

GFS shifting pretty far left, maybe the NHC track is not too bad after all...,

[HurricaneJosh]

The NHC is very good about not overreacting to run-to-run windshield wiping. They usually wait to make sure that a shift is a real trend before making a big change to the forecast track.

[biodhokie]

WSI RPM 944mb landfall in the Delaware Bay. WV gets clobbered with many feet of snow.

The mets at the local nws office are severely downplaying the event...bufkit is stating 17" @ around 1200 ft in elevation at kmgw and not even a winter weather advisory...yet. If the models verify around here you might see a lot of "we didn't know it was going to be this bad!" coming out of WV.

[Cheeznado]

Just faster, landfall over or a hair south of NYC Monday afternoon/evening. About 952

[marsman]

The mets at the local nws office are severely downplaying the event...bufkit is stating 17" @ around 1200 ft in elevation at kmgw and not even a winter weather advisory...yet. If the models verify around here you might see a lot of "we didn't know it was going to be this bad!" coming out of WV.

Winter Storm Watch up for Elkins/Snowshoe, calling for 10"-14".

[WeatherNC]

The NHC is very good about not overreacting to run-to-run windshield wiping. They usually wait to make sure that a shift is a real trend before making a big change to the forecast track.

Ph.D

You have to wonder though, we saw the ET transition taking place last night, >24hrs ago, yet the NHC is still holding on to her, min Cat 1 @ 969. Earlier thinking by them was TS in the 12-36, then back to a Cane. Trillion dollars to a cheese bagel, they keep it 75-80mph as the mslp begins decent.

There needs to be a better correlation between central pressure and a 2 min avg fixed point nw side, impacts on a larger scale never correlate proportionally to the wind, 954 Cat 1, seriously? NHC should be handing this off to the HPC as we speak, or at-least in strong contact with them. This is, and has not been for awhile a hurricane, loop a high res wv, case in point.

So WTF is it, no idea. Hybrid of some type, pressure peaked on the high side around 970, slow decrease from here on out, followed be somewhat rapid deepening as it does a hard left into the central mid-atlantic.

WV valid 11:45est

IR valid 11:45est

Part of her got sheared off into the ATL, likely into the St. Johns Island cyclone routed underneath the ridge building down

[HurricaneJosh]

Ph.D

?

You have to wonder though, we saw the ET transition taking place last night, >24hrs ago, yet the NHC is still holding on to her, min Cat 1 @ 969. Earlier thinking by them was TS in the 12-36, then back to a Cane. Trillion dollars to a cheese bagel, they keep it 75-80mph as the mslp begins decent.

There needs to be a better correlation between central pressure and a 2 min avg fixed point nw side, impacts on a larger scale never correlate proportionally to the wind, 954 Cat 1, seriously? NHC should be handing this off to the HPC as we speak, or at-least in strong contact with them. This is, and has not been for awhile a hurricane, loop a high res wv, case in point.

So WTF is it, no idea. Hybrid of some type, pressure peaked on the high side around 970, slow decrease from here on out, followed be somewhat rapid deepening as it does a hard left into the central mid-atlantic.

I agree with you-- it really doesn't look like a 'cane anymore-- but I also understand the logistical reasons for having the NHC continue to "own" the system and related warnings. It's just more efficient.

[WeatherNC]

?

Reference to the diplomas in place making "the" call to keep it a hurricane.

[tornadotony]

Ph.D

You have to wonder though, we saw the ET transition taking place last night, >24hrs ago, yet the NHC is still holding on to her, min Cat 1 @ 969. Earlier thinking by them was TS in the 12-36, then back to a Cane. Trillion dollars to a cheese bagel, they keep it 75-80mph as the mslp begins decent.

There needs to be a better correlation between central pressure and a 2 min avg fixed point nw side, impacts on a larger scale never correlate proportionally to the wind, 954 Cat 1, seriously? NHC should be handing this off to the HPC as we speak, or at-least in strong contact with them. This is, and has not been for awhile a hurricane, loop a high res wv, case in point.

So WTF is it, no idea. Hybrid of some type, pressure peaked on the high side around 970, slow decrease from here on out, followed be somewhat rapid deepening as it does a hard left into the central mid-atlantic.

WV valid 11:45est

IR valid 11:45est

Part of her got sheared off into the ATL, likely into the St. Johns Island cyclone routed underneath the ridge building down

I don't follow a whole lot of this post, but the parts I do follow are just not meteorologically accurate. Is it hurricane intensity? My guess is not quite, but it's probably pretty intense. As for passing off to HPC, absolutely not. Whether you or anyone else likes it or not, the recon data firmly suggests it is still a warm-core system, with a peak in temperature near the center. Thus, it's NHC's territory.

[WeatherNC]

I don't follow a whole lot of this post, but the parts I do follow are just not meteorologically accurate. Is it hurricane intensity? My guess is not quite, but it's probably pretty intense. As for passing off to HPC, absolutely not. Whether you or anyone else likes it or not, the recon data firmly suggests it is still a warm-core system, with a peak in temperature near the center. Thus, it's NHC's territory.

Tony, this is coming from more of a symmetry standpoint, in conjunction with the broadening of the wind-field, delta t between the inner and outer. 9/11C. Granted the NHC has the ball so to speak, but classifying this cyclone as purely tropical when in fact the wind field, structural presentation, and potential impact, which could be historic, makes me second guess the system (and scale) in place, leaves a great deal to question.

[jwilson]

Being in West Virginia, I'm a little concerned that the combination of wind and rain/snow will create a lot of problems. This state does not take care of the roads, and our power grid is very sensitive. Several lesser storms have almost knocked out the power, and during the storms of '09--although I wasn't here--power was out for a week or so. Also some WS Watches are already in place, 72 hours (or less now) outside of the event. Part of me wonders if the chances of a historical storm are being overdone, but I'm not used to this sort of scenario. I'm more used to tracking winter storms and have a better idea of what to expect there.

I don't recall a storm being hyped quite as much as this in recent memory. For whatever reason Irene is a blur to me, probably because the impact out here was minimal.

[tornadotony]

Tony, this is coming from more of a symmetry standpoint, in conjunction with the broadening of the wind-field, delta t between the inner and outer. 9/11C. Granted the NHC has the ball so to speak, but classifying this cyclone as purely tropical when in fact the wind field, structural presentation, and potential impact, which could be historic, makes me second guess the system (and scale) in place, leaves a great deal to question.

Of course there's a great deal to question here. These storms don't happen every decade. We compartmentalize a lot in meteorology out of sheer necessity. In reality, the atmosphere doesn't live in boxes. In this case, you're likely to have a defined barotropic center embedded within a baroclinic cyclone. There's no conspiracy here. The best way to convey this rather immense threat to the public, given that the arguments for NHC and HPC jursidiction/tropical and extratropical characterization are likely to be roughly equal when it really matters, is to advise it as a tropical cyclone because that gets people's attention way more than calling it a Nor'easter would. Simple as that.

[Chicago Storm]

I don't follow a whole lot of this post, but the parts I do follow are just not meteorologically accurate. Is it hurricane intensity? My guess is not quite, but it's probably pretty intense. As for passing off to HPC, absolutely not. Whether you or anyone else likes it or not, the recon data firmly suggests it is still a warm-core system, with a peak in temperature near the center. Thus, it's NHC's territory.

On top of that it has also been mentioned by mets on the board several times that the NHC will likely hold onto the tropical designation through landfall due the the circumstances.

[Ed Lizard]

I can't reveal sources, but I heard indirectly from pretty reliable source- no matter what Sandy becomes as far as sub-tropical or extra-tropical, decision has been made that NHC will handle coastal warnings until landfall, instead of local NWS WFOs to avoid confusion.

After landfall, WFOs will start issuing warnings/advisories of their own re coastal/marine warnings, HPC will start advisories on 'Post-Tropical Storm Sandy'.

[WeatherNC]

Agree, but to classify this as a hurricane when in fact it is not, in my opinion leaves agreat deal to question. Sure, it has warm core around 10C presently with really no separation on the immediate outside, at the mid levels those 570's will crash into the 530's H5 dm, what happens in between? All I am saying is that there need to be a better system and scale I'm place to quantify the impacts in terms of sensible weather to the general public. Weakening Sandy to a TS before she is partially ingested into a Arctic front is not realistic in terms of impacts along the MA coast, we think TS, 40-60mph, when in fact hurricane warnings will be going up in earnest for areas from BOS down to the Delmarva.

[Cheeznado]

BTW, some deeper convection blowing up just north of the center......

[David Reimer]

I can't reveal sources, but I heard indirectly from pretty reliable source- no matter what Sandy becomes as far as sub-tropical or extra-tropical, decision has been made that NHC will handle coastal warnings until landfall, instead of local NWS WFOs to avoid confusion.

After landfall, WFOs will start issuing warnings/advisories of their own re coastal/marine warnings, HPC will start advisories on 'Post-Tropical Storm Sandy'.

In addition to that, the uniform policy is the name "Sandy" or "Post-Tropical Sandy" will be used. No other names will be used in products. Thus if it becomes a Nor'Easter, it will remain Sandy in the eyes of the NWS. No giving it halloween names.

[tornadotony]

Agree, but to classify this as a hurricane when in fact it is not, in my opinion leaves agreat deal to question. Sure, it has warm core around 10C presently with really no separation on the immediate outside, at the mid levels those 570's will crash into the 530's H5 dm, what happens in between? All I am saying is that there need to be a better system and scale I'm place to quantify the impacts in terms of sensible weather to the general public. Weakening Sandy to a TS before she is partially ingested into a Arctic front is not realistic in terms of impacts along the MA coast, we think TS, 40-60mph, when in fact hurricane warnings will be going up in earnest for areas from BOS down to the Delmarva.

So are you saying, if it weakens below hurricane status tonight, that we should call it "Once-Again-Soon-to-be-Hurricane Sandy"? I really don't follow...

[wolfman23601]

When does the new Euro come out? If it lands anywhere from CNJ to Long Island, I'd say it's settled with a narrow cone.

[SN_Lover]

BTW, some deeper convection blowing up just north of the center......

divergence is strengthening and shear is beginning to weaken at the moment. or could the convection be causing the divergence?

[yoda]

When does the new Euro come out? If it lands anywhere from CNJ to Long Island, I'd say it's settled with a narrow cone.

About 45 mins

[Supercane]

IMO, Sandy is a case of an exotic breed -- a hurricane-force subtropical storm (or subtropical hurricane).

To my knowledge, NHC doesn't have an official way of separating these systems from either fully tropical hurricanes or <74mph subtropical storms. I think in practice they just call them hurricanes (as they are doing with Sandy now), which is probably the most logical category for operational purposes.

[Cheeznado]

You are all wrong, the media has already dubbed it "Frankenstorm"

[Ed Lizard]

BTW, for scientific purists, NHC can keep responsibility until landfall for a storm that may cause sustained hurricane force winds on the coast, as a matter of public safety, and in post season review declare it became extra-tropical while still offshore.

[heavy_wx]

divergence is strengthening and shear is beginning to weaken at the moment. or could the convection be causing the divergence?

There is a 70 kt jet streak to the southeast of Sandy at 300 mb downstream of a trough. This puts the system in the divergent left exit region.

[phil882]

Right now the perfect analog to the storm structure we are experiencing right now is Irene (1999)... NOT Irene 2011, which looked very anemic convectively but remained fully warm core as it interacted with an upper level PV anomaly. The storm structure with Sandy will likely recover as long as the convection on the left flank of the circulation continues to erode the upper level trough though diabatic heating. In Irene's case we saw a very unexpected deepening as it remained over the gulf stream and accelerated away from the NC coastline. Sandy is a larger storm and probably won't have the same unexpected deepening that Irene did, but I do think we will see Sandy regain some of its former convective vigor and some symmetry as it moves further northeast in the next 24-36 hours.

[SN_Lover]

Right now the perfect analog to the storm structure we are experiencing right now is Irene (1999)... NOT Irene 2011, which looked very anemic convectively but remained fully warm core as it interacted with an upper level PV anomaly. The storm structure with Sandy will likely recover as long as the convection on the left flank of the circulation continues to erode the upper level trough though diabatic heating. In Irene's case we saw a very unexpected deepening as it remained over the gulf stream and accelerated away from the NC coastline. Sandy is a larger storm and probably won't have the same unexpected deepening that Irene did, but I do think we will see Sandy regain some of its former convective vigor and some symmetry as it moves further northeast in the next 24-36 hours.

Was this expected to occur by the models? or is this something that wasnt forecasted beforehand?

[Derecho!]

You are all wrong, the media has already dubbed it "Frankenstorm"

HPC named it Frankenstorm, not the media.