Hurricane Sandy/Nor'easter?

By: Zachary Labe , 2:18 PM GMT on October 23, 2012

Share this Blog
4
+

And so it begins. Yet again we are kicking off the end of October tracking another potential Nor'easter. Similar to last October, the threat of high winds, heavy rain, and heavy snow are a possibility. The synoptic setup is very different though in this instance and many different outcomes are possible.

Presently tropical storm Sandy is located in the central Caribbean tracking 0 degrees north.

It is encountering very little vertical shear (sub 10-15 knots) and slightly above normal SST's (80F+). Sandy will begin to increase in speed as it tracks north towards Cuba. A bit of drier air and increased shear along with the high mountain interactions with the tropical core, will weaken Sandy and prevent further strengthening. Intensity forecasts through Friday are only expected to peak at a minimal hurricane. As Sandy tracks north of the Bahamas encountering a more hostile environment, she will begin to take on extratropical characteristics. This time frame is around Saturday/Sunday. The track and intensity after this period is a bit more in question and will be detailed further below:

A deep negatively tilted trough will be swinging south through the central part of the nation by the end of the week. This feature is key in predicting the eventual path and impacts of Sandy. Located to the north is a very impressive blocking setup with an amplified ridge over Greenland and a steep west based negative NAO. The North Atlantic Oscillaion will be approaching the lowest value in several months during this time frame.

The blocking setup will allow for a very amplified jet stream pattern that is also slow moving. Three major scenarios are possible for the impacts of Sandy on the east coast.

1) Currently the 10/23/2012 runs of the GGEM and ECMWF are the most amplified and feature a tightly wrapped extratropical Sandy tracking up the eastern seaboard with a slightly northwest motion. They are also supported by this morning's 0z runs which have impressive consistency in allowing the negatively tilted upper level trough to capture and phase Sandy.

A broad precipitation deck forms while the surface low undergoes rapid bombogenesis courtesy of impressive baroclinic forcing. In some recent foreign model runs, the surface low has dropped sub 950hPa. A tight pressure gradient and raging low level jet sends strong winds to the surface in excess of 50mph up and down the Northeast. Meanwhile the cold air behind the front catches up to Sandy in a pocket of sub 0C H85 thermals located west of the center of circulation. Surface temperatures also fall due to dynamic cooling with heavy snow breaking out across western Maryland through all of central Pennsylvania. In fact the 0z 10/23/2012 ECMWF shows snow accumulations in excess of 12-24in from Reading west to the Laurel Highlands south to Hagerstown, MD and north to Elmira, NY.

Knowing a bit about 500mb maps shows that this solution requires many features to time perfectly to be able to capture Sandy and track with a slight northwest component. It is a dynamic setup and the anomalous blocking to the north makes this particularily more interesting than normally. This is also impressive and consistent support from both operation and individual ensemble guidance especially from the GGEM and ECWMF. A few ECWMF ensembles even show the surface low tracking right through southern New England with a landfall coming from the northeast near Cape Cod, Massachusetts. This setup would cause major problems up and down the eastern seaboard with heavy rain, high winds, coastal storm surge, and possibly heavy snow. Looking back at other analogs, Hurricane Wilma is a quick reminder how a system with tropical origins can quickly resemble a nor'easter with winter-like characteristics.

Key players to watch for the scenario require analysis of the 300mb and 500mb trough axis and tilt including time of these features for the upper level trough. Also the evolution will be highly dependent on the upstream position of the upper level heights near Greenland (blocking).

2) Another scenario is supported by the OP GFS and GEFS. In this evolution the overall jet stream is flatter and the trough lags behind a bit allowing Sandy to not phase and instead swing out to sea.

Therefore any precipitation in the Northeast is a direct result of the cold front and a small inverted trough feature in New England. A recent update in the GFS enembles this morning (6z run) show a clear west shift in about half of the models. This is a critical note to make especially when looking at future run times. Presently this evolution has support from the HPC and other NWS offices, although given recent developments for the ensembles and forecasts for blocking, it is starting to lose gravity.

3) For the time being, the following option has the most support looking at the overall orientation of the jet stream and synoptic setup. While this is a middle ground approach, it offers the most logical evolution given past analogs and our recent weather pattern over the last few months. Model support is lacking as most guidance is in the camps of the two extremes listed above. Nevertheless this possiblity allows Sandy to begin to rapidly take on extratropical characteristics and begin to wash out over the Atlantic as power vertical shear takes hold. A negatively titled -2SD trough will move east from the Ohio Valley and the interaction between the two features allows Sandy to track out to sea. But an inverted trough feature forms along the eastern periphery of the trough particularily towards New England. In almost a similar PRE (predecessor rain event) manner, an axis of +2SD PWATs would pool across New England as heavy rain streams through the region. QPF probably would be in excess of 1-2in given the inverted trough has tropical origins from post-Sandy. A screaming low level jet would also allow for gale force winds along the immediate coastline. Farther west and south impacts would rapidly diminish and mainly allow for a small corridor of rain showers along the immediate front. Both the GGEM and GFS show slight hints of this inverted trough feature.

Conclusion) It is a complex setup given both tropical and non-tropical features that need to interact to produce a solution with a surface low undergoing rapid cyclogenesis and pinwheels northwest sub 940hPa. Therefore given that Sandy just developed and is still located in the central to southern Caribbean, forecasts at this point can be taken with a grain of salt. It is important to note at this point the overall orientation of the jet stream and past analogs given the setup. Also the continuous support for dense upstream blocking is beginning to make odds of some sort of impact on the Northeast particularily higher than just a day or two ago. A few forecasts are already rotating about the cyber world concerning a grim storm tracking towards the east coast. These have little to no support and should be thrown out. The time frame for impact is early next week in the 144-174 hour time frame according to 0z 10/23/2012 model runs. Keep an eye the next few days on ensemble shifts and trends particularily in the timing of any possible phase of Sandy with the upper level trough.

As a final note as of 10/23/2012 at 10am, latest upper level air reports out of Sandy indicate the presssure dropping to 996mb with winds aloft up to 60 knots. Impressive strengthening and it is all courtesy of the warm bath water in the Caribbean.

Stay tuned and discuss below!

Follow my 24hr forecasts on Twitter... Link and Facebook... Link.

"Lower Susquehanna Valley Doppler"

(Courtesy of WGAL)

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

Sign In or Register Sign In or Register

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 185 - 135

Page: 1 | 2 | 3 | 4 | 5Blog Index

hey blizz
hope ya don't mind me stopping by
normally i don't show up till after cane season
but i am a little early this year
Member Since: July 15, 2006 Posts: 187 Comments: 57781
Quoting MariettaMoon:


I can do some really cool stuff, maps & analysis with GIS! Love it. I'll be getting more into the computer science side of things next year in Advanced GIS.

It's funny, so many GIS students are transfers from meteorology.

I had a python and fortran class last semester. We also used the meteorology software GrADS.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
x
Member Since: July 15, 2006 Posts: 187 Comments: 57781
x
Member Since: July 15, 2006 Posts: 187 Comments: 57781
x
Member Since: July 15, 2006 Posts: 187 Comments: 57781
Quoting colortheworld:
WOW. Strong TS wind gusts as far as State College?


TS gusts as far as Chicago and well into Canada for that matter.
Member Since: Posts: Comments:
Quoting Blizzard92:

GIS! That is awesome! Have you done any computer science work?

I could see how it is possible for winds to gust 65mph+ for areas near the center. It should be interesting to watch. Although I would not completely rule out New England. The ECMWF ensembles are a bit farther north in track.


I can do some really cool stuff, maps & analysis with GIS! Love it. I'll be getting more into the computer science side of things next year in Advanced GIS.

It's funny, so many GIS students are transfers from meteorology.
Member Since: Posts: Comments:
I have my grandfather's barometer...it is from 1862...Not sure how he got it. I wish it still worked. He predicted the storm of 1938 with it. Not that he knew it was a hurricane but the barometer dropped so quickly that he went to the town center, (Lancaster, MA) and told people that 'something terrible' was going to happen. During that storm every tree on Main Street went down.....Besides being interested in weather he also devised some ammunition. Homer Guy Loverin.
Member Since: September 10, 2001 Posts: 2 Comments: 486
WOW. Strong TS wind gusts as far as State College?
Member Since: August 22, 2012 Posts: 0 Comments: 7
That is a large wind field.
Member Since: Posts: Comments:
Quoting Blizzard92:

He just declared on twitter that if the GFS is on track, windows will be blown out of NYC buildings.

I think his statement is somewhat reasonable. When looking at a bufkit sounding I see the 18z GFS has 97kt winds at 2kft and I don't know of too many windows that can withstand 110mph winds...

Of course this statement is alarmist based off of the fact that the storm may not take the GFS track, but scientifically it's a reasonable assumption in my opinion...more reasonable than anything he's said the last two days anyway...
Member Since: August 5, 2010 Posts: 0 Comments: 588
DON'T HOTLINK, BLIZZ!
Member Since: August 22, 2012 Posts: 0 Comments: 7
Wow... 18z GFS surface winds (gusts in mph)

Link
Member Since: December 14, 2007 Posts: 285 Comments: 15142
That's just about every river in the Mid-Atlantic, Susquehanna, Potomac, Juniata, Delaware, Hudson, etc etc etc.
Member Since: August 22, 2012 Posts: 0 Comments: 7
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Once the storm begins moving ashore,will the winds be strongest on the northwest or northeast side?Here in southern Delaware it may not make much of a difference.
Member Since: Posts: Comments:
Quoting Blizzard92:

That converts to 986mb.


Thanks i actually think the "official" pressure was lower, from what i could find in Philly for the superstorm that was a record low pressure around 28.50
Member Since: January 22, 2011 Posts: 0 Comments: 551
Wow... So this won't be a punch - it's gonna be a beating :(
Member Since: Posts: Comments:
As a weather fan, but casual at that compared to others in this chat, I think this is a much more accurate and dependable way of getting information for these BIG storms. Based on the above posts it appears that I need to follow this Margusity character immediately. Sounds like pure entertainment.

The Size of storm is the "unprecedented" part, but ultimately it seems like a strong Noreaster. Midatlantic isnt getting hit with a Cat 2 hurricane... right? right? Thanks for all the posts and info, ill be back saturday, I think thats when we will really have a sense of specifics.
Member Since: Posts: Comments:
At PC: News showed force main, 36 in dia. leading from Swimming River Reservoir near Red Bank in temporary position. Old pipe was supported on viaduct across the or near the spillway of the Dam. This support was undermined during Irene and resulted in pipe collapse. Water restrictions were in place for some time. The replacement is not finished. The temp. pipe is sitting on timber dunnage and oak centering wedges near the old washout. You might want to do a drive by and see conditions. If HM is now on the bandwagon and correct you may be drinking perrier for a while.
Member Since: February 27, 2009 Posts: 0 Comments: 3279
Quoting PengSnow:
Cleaning off the old barometer, the lowest I had when I first lived in pgh in 1993 was 29.12--Superstorm 1993--the manual dial is set to that. If everything forecasted by the current models is close to right, I might see under that. This will end up being a Movie.

That converts to 986mb.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Quoting Blizzard92:

He just declared on twitter that if the GFS is on track, windows will be blown out of NYC buildings.


The guy might need some happy meds to bring him down from his perch. Poor thing! He's beside himself. But jeez, that is a scary thought.
Member Since: October 14, 2006 Posts: 1 Comments: 639
Cleaning off the old barometer, the lowest I had when I first lived in pgh in 1993 was 29.12--Superstorm 1993--the manual dial is set to that. If everything forecasted by the current models is close to right, I might see under that. This will end up being a Movie.
Member Since: January 22, 2011 Posts: 0 Comments: 551
Quoting Blizzard92:

He just declared on twitter that if the GFS is on track, windows will be blown out of NYC buildings.


*facepalm*
Member Since: August 22, 2012 Posts: 0 Comments: 7
***Tomorrow by 10am I will have my official blog out for Sandy. I know it will be an early forecast, but it is the only time I have to get a full entry posted.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
If you have the day off tomorrow, go shopping. Buy your storm bootie ASAP. Saturday will be a mess. There's gonna be a miserable run on the stores this weekend. Don't forget lanterns, blankets, nonperishable food items and medications. Make sure there are no lose tree limbs. Check your gutters. Don't forget the pets. And for God's sake, don't run out of toilet paper.

In other words, don't be scared, be prepared.
Member Since: October 14, 2006 Posts: 1 Comments: 639
P C has a great point. Last year and to some extent this year, the NHC model as many others, has shown an indifference to the presence of dry air. Suspect if prior performance is a clue to predictions, the storm will stall or slow forward momentum, pressure drop will steady or rise and the storm will tend to advance quickly once it begins to gather itself. Expect the center to be impacted. Once the dry air has been cut off, say 24-48 hours then things will start to cook. It will then head due N. or turn to NNE. It made 5 deg of lat today or more. Lets see if that pace continues without benefit of sun and continued feed of dry air.

Sandy left a bit of energy behind in the southern Caribbean. We may see one more shot from here before the season is over.
Member Since: February 27, 2009 Posts: 0 Comments: 3279
Quoting MariettaMoon:


Hey, thanks. Wow, you really think it could get like that?

I'm very busy with school. Learning GIS this year, it's pretty awsome but a ton of work! Colleges in PA are threatening a strike by the end of this semester.

GIS! That is awesome! Have you done any computer science work?

I could see how it is possible for winds to gust 65mph+ for areas near the center. It should be interesting to watch. Although I would not completely rule out New England. The ECMWF ensembles are a bit farther north in track.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Quoting colortheworld:
Margusity's epic meltdown comes full circle:

Big Daddy hat will be on tomorrow. Original OTS forecast thrown out going with disaster storm. Time to go into storm mode! This will be the biggest storm in decades if all the models are correct. NAO is going to -2.5 which means watch out! I think the problem was I recognized the low NAO, but tried to make a new storm instead of excepting Sandy as the storm due to the low NAO.

This is coming from a man who seemed ready to kill himself live on the internet just an hour or two ago to defend his call of "OUT TO SEEEEEEEEEEEE!!!!"*

* Yes, I spelled "sea" wrong on purpose, you know, for teh lulz.

He just declared on twitter that if the GFS is on track, windows will be blown out of NYC buildings.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Margusity's epic meltdown comes full circle:

Big Daddy hat will be on tomorrow. Original OTS forecast thrown out going with disaster storm. Time to go into storm mode! This will be the biggest storm in decades if all the models are correct. NAO is going to -2.5 which means watch out! I think the problem was I recognized the low NAO, but tried to make a new storm instead of excepting Sandy as the storm due to the low NAO.

This is coming from a man who seemed ready to kill himself live on the internet just an hour or two ago to defend his call of "OUT TO SEEEEEEEEEEEE!!!!"*

* Yes, I spelled "sea" wrong on purpose, you know, for teh lulz.
Member Since: August 22, 2012 Posts: 0 Comments: 7
Quoting Blizzard92:

Hey! How is it going?

Quick bio... Link
Hurricane Hazel on October 15. Winds gusted from 75 to100 mph in eastern
Pennsylvania as the storm tracked through. Philadelphia International Airport clocked 94
mph, Reading, 86 mph, Allentown, 82 mph and Harrisburg, 80 mph. Total rainfall of 4 to
6 inches caused extensive flash flooding in western Pennsylvania. Most of central and
eastern Pennsylvania collected less than 2 inches. The last three inland hurricanes of
the Mid-Atlantic, the storms of 1878, 1896 and 1954, tracked through eastern
Pennsylvania.


Hey, thanks. Wow, you really think it could get like that?

I'm very busy with school. Learning GIS this year, it's pretty awsome but a ton of work! Colleges in PA are threatening a strike by the end of this semester.
Member Since: Posts: Comments:
It seems like Southern New England is now out of the bullseye on this. Anyone else have any insight as to how it might effect us up here?
Member Since: Posts: Comments:
Quoting 6w6chick:
Hi Zach & company - I've been keeping an eye on all of the reports and your blog and it looks like we are definitely looking at having this storm impact us in the mid-atlantic. I haven't seen too much in the way of how fast the storm is to move out once it comes inland. Any thoughts?

It is a slow mover once inland as it is captured by the trough. Given the long wavelengths and blocky pattern, this system will plague the reach for multiple days and likely exacerbate coastal flooding particularly in vulnerable areas such as the Long Island Sound.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Hi Zach & company - I've been keeping an eye on all of the reports and your blog and it looks like we are definitely looking at having this storm impact us in the mid-atlantic. I haven't seen too much in the way of how fast the storm is to move out once it comes inland. Any thoughts?
Member Since: Posts: Comments:
Quoting MariettaMoon:


Hello hello! Long-time-no.

What were Hazel-like strangths in the LSV?

ECMWF has some serious snowfall totals for somebody.

Hey! How is it going?

Quick bio... Link
Hurricane Hazel on October 15. Winds gusted from 75 to100 mph in eastern
Pennsylvania as the storm tracked through. Philadelphia International Airport clocked 94
mph, Reading, 86 mph, Allentown, 82 mph and Harrisburg, 80 mph. Total rainfall of 4 to
6 inches caused extensive flash flooding in western Pennsylvania. Most of central and
eastern Pennsylvania collected less than 2 inches. The last three inland hurricanes of
the Mid-Atlantic, the storms of 1878, 1896 and 1954, tracked through eastern
Pennsylvania.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Quoting Blizzard92:
If Sandy tracks in a similar manner to the GFS/ECMWF, winds in the LSV could approach Hazel-like strengths!


Hello hello! Long-time-no.

What were Hazel-like strengths in the LSV?

ECMWF has some serious snowfall totals for somebody.

I wonder what the weather channel is going to do about naming this one. Sandy or something with the letter A? haha. It could mess up their whole system before it even begins!
Member Since: Posts: Comments:
If Sandy tracks in a similar manner to the GFS/ECMWF, winds in the LSV could approach Hazel-like strengths!
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Yeah I figure that. There's a group of us going so we have to make the call to leave for the airport and get stuck there or just stay put.
Member Since: Posts: Comments:
WillHershey, I would definitely be checking your flight status on Monday, if this pans out there will be alot of flight cancellations and maybe some airport closures.
Member Since: January 31, 2009 Posts: 0 Comments: 8011
Thanks Zach I'm looking forward to going away but would love to witness this storm mostly if it really impacts our area. Too bad it's not 20 degrees cooler right now.
Member Since: Posts: Comments:
Quoting Blizzard92:

Yep, enough cold air is drawn into the system. The models have been consistent in showing West Virginia receiving a major snow storm for the higher elevations, and this possibly may include the ridges for southwestern Pennsylvania. Some guidance such as the 18z GFS even shows a cold pocket forming from dynamic cooling as the low becomes cutoff over central Pennsylvania. It is a definite possibility, but the details for snow are probably the most uncertain portion of the forecast at this point. Although I think it is definitely possible somebody sees a major snowstorm out of this (most likely the Appalachians).


Thanks Blizz, and i am just using History and I know that forecasting is well advanced than 20 years ago, but I have a feeling if this hits as now predicted, the temperatures are going to be a lot colder. There is truly huge uncertainties. Weather's fun to watch but many people are going to be hurt in one form or another.
Member Since: January 22, 2011 Posts: 0 Comments: 551
Quoting WillHershey:
There's still plenty of leaves on trees here in Hershey Pa. They are at the peak of color so if we do get the wind most of them will be coming down. I'm just worried about the basement flooding again mostly since I'm suppose to fly out of Philly Monday around lunch time for four days.

If a landfall between Ocean City, MD to central NJ occurs then 5-10in of rain is possible for the lower susquehanna valley. Should a track farther to the north occur, less rain can be expected.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
There's still plenty of leaves on trees here in Hershey Pa. They are at the peak of color so if we do get the wind most of them will be coming down. I'm just worried about the basement flooding again mostly since I'm suppose to fly out of Philly Monday around lunch time for four days.
Member Since: Posts: Comments:
Quoting PengSnow:
Blizz, how much cold air will be pulled in? Lets say for western, pa and eastern, oh? If the storm will be that potent, would it then pull in colder temperatures than forecasted. Even referencing the March 1993 Superstorm, temperatures were forcasted 3 days out were in the mid 20s for lows, after and during the 93 storm temperatures dropped like a rock to sub zero the night of the storm as it ended.

Lastly, It is kind of funny that on the local NOAA site the records temps were back from 1991 for this date in Pittsburgh---that Halloween year even though the snow did not lay in on the road and but did on the grass--we were able to build a Pumpkin Headed Snowman---that was the year of the "Perfect Storm".,

Yep, enough cold air is drawn into the system. The models have been consistent in showing West Virginia receiving a major snow storm for the higher elevations, and this possibly may include the ridges for southwestern Pennsylvania. Some guidance such as the 18z GFS even shows a cold pocket forming from dynamic cooling as the low becomes cutoff over central Pennsylvania. It is a definite possibility, but the details for snow are probably the most uncertain portion of the forecast at this point. Although I think it is definitely possible somebody sees a major snowstorm out of this (most likely the Appalachians).
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Blizz, how much cold air will be pulled in? Lets say for western, pa and eastern, oh? If the storm will be that potent, would it then pull in colder temperatures than forecasted. Even referencing the March 1993 Superstorm, temperatures were forcasted 3 days out were in the mid 20s for lows, after and during the 93 storm temperatures dropped like a rock to sub zero the night of the storm as it ended.

Lastly, It is kind of funny that on the local NOAA site the records temps were back from 1991 for this date in Pittsburgh---that Halloween year even though the snow did not lay in on the road and but did on the grass--we were able to build a Pumpkin Headed Snowman---that was the year of the "Perfect Storm".,
Member Since: January 22, 2011 Posts: 0 Comments: 551
140. Gaara
Since I never really got a chance to do this last year, I'm going to bust out my fantasy weather game again.

$15 bounty to the charity of the winner's choice for whoever guesses the minimum recorded SLP in the US from this storm. Please include a location, as well, for a tiebreaker. You can use the same pressure as someone else, but you cannot also use the same city.

I'm going with 951mb at Tom's River NJ.

Guesses are due by noon eastern on Saturday.

And GO!
Member Since: December 27, 2010 Posts: 0 Comments: 477
Quoting WillHershey:
So do expect the same amount of flooding from this storm compare to last year?

Flooding will definitely not be as bad as the September flooding of last year. The water levels for instance on the Swatara were a once in a lifetime event. How is the foliage down that way? If the center of the remnants of Sandy end up tracking through the LSV, there could be some pretty strong winds.
Member Since: December 14, 2007 Posts: 285 Comments: 15142
-Forecasters Warn East Coast About 'Frankenstorm' (ABC News)

--Not a trick or a treat: Hurricane Sandy could hit as monster hybrid storm (Christian Science Monitor)

--‘Frankenstorm’ shaping up to slam East Coast (Boston Herald)

--'Dangerous' Hurricane Sandy and resulting Frankenstorm may impact LI, forecasters say (Newsday)
Member Since: Posts: Comments:
So do expect the same amount of flooding from this storm compare to last year?
Member Since: Posts: Comments:
Quoting colortheworld:
Margusity is having a meltdown on facebook. Anybody know why?

hahahah... yes I am seeing that too!
Member Since: December 14, 2007 Posts: 285 Comments: 15142
Margusity is having a meltdown on facebook. Anybody know why?
Member Since: August 22, 2012 Posts: 0 Comments: 7

Viewing: 185 - 135

Page: 1 | 2 | 3 | 4 | 5Blog Index

Top of Page

About Blizzard92

Cornell University- Atmospheric Sciences Undergrad; Research Assist.- Onset of Spring Indices Toolbox; Interests- Small spatial scale climatolology

Local Weather

Mostly Cloudy
43 °F
Mostly Cloudy

Blizzard92's Recent Photos

Fall in Ithaca
Snow Fluff
Deep Creek and Wisp, MD
Deep Creek and Wisp, MD

Personal Weather Stations

About Personal Weather Stations