Hurricane Sandy's huge size: freak of nature or climate change?

By: Dr. Jeff Masters , 1:10 PM GMT on November 13, 2012

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Hurricane Sandy was truly astounding in its size and power. At its peak size, twenty hours before landfall, Sandy had tropical storm-force winds that covered an area nearly one-fifth the area of the contiguous United States. Since detailed records of hurricane size began in 1988, only one tropical storm (Olga of 2001) has had a larger area of tropical storm-force winds, and no hurricanes has. Sandy's area of ocean with twelve-foot seas peaked at 1.4 million square miles--nearly one-half the area of the contiguous United States, or 1% of Earth's total ocean area. Most incredibly, ten hours before landfall (9:30 am EDT October 30), the total energy of Sandy's winds of tropical storm-force and higher peaked at 329 terajoules--the highest value for any Atlantic hurricane since at least 1969. This is 2.7 times higher than Katrina's peak energy, and is equivalent to five Hiroshima-sized atomic bombs. At landfall, Sandy's tropical storm-force winds spanned 943 miles of the the U.S. coast. No hurricane on record has been wider; the previous record holder was Hurricane Igor of 2010, which was 863 miles in diameter. Sandy's huge size prompted high wind warnings to be posted from Chicago to Eastern Maine, and from Michigan's Upper Peninsula to Florida's Lake Okeechobee--an area home to 120 million people. Sandy's winds simultaneously caused damage to buildings on the shores of Lake Michigan at Indiana Dunes National Lakeshore, and toppled power lines in Nova Scotia, Canada--locations 1200 miles apart!

Largest Atlantic tropical cyclones for area covered by tropical storm-force winds:

Olga, 2001: 780,000 square miles
Sandy, 2012: 560,000 square miles
Lili, 1996: 550,000 square miles
Igor, 2010: 550,000 square miles
Karl, 2004: 430,000 square miles



Figure 1. Hurricane Sandy’s winds (top), on October 28, 2012, when Sandy was a Category 1 hurricane with top winds of 75 mph (this ocean surface wind data is from a radar scatterometer on the Indian Space Research Organization’s (ISRO) Oceansat-2.) Hurricane Katrina’s winds (bottom) on August 28, 2005, when Katrina was a Category 5 hurricane with top winds of 175 mph (data taken by a radar scatterometer on NASA’s defunct QuickSCAT satellite.) In both maps, wind speeds above 65 kilometers (40 miles) per hour are yellow; above 80 kph (50 mph) are orange; and above 95 kph (60 mph) are dark red. The most noticeable difference is the extent of the strong wind fields. For Katrina, winds over 65 kilometers per hour stretched about 500 kilometers (300 miles) from edge to edge. For Sandy, winds of that intensity spanned an region of ocean three times as great--1,500 kilometers (900 miles). Katrina was able to generate a record-height storm surge over a small area of the Mississippi coast. Sandy generated a lower but highly destructive storm surge over a much larger area, due to the storm's weaker winds but much larger size. Image credit: NASA.

How did Sandy get so big?
We understand fairly well what controls the peak strength of a hurricane's winds, but have a poor understanding of why some hurricanes get large and others stay small. A number of factors probably worked together to create a "prefect storm" situation that allowed Sandy to grow so large, and we also must acknowledge that climate change could have played a role. Here are some possible reasons why Sandy grew so large:

1) Initial size of the disturbance that became Sandy was large
Sandy formed from an African tropical wave that interacted with a large area of low pressure that covered most of the Central Caribbean. Rotunno and Emanuel (1987) found that hurricanes that form from large initial tropical disturbances like Sandy did tend to end up large in size.


Figure 2. The initial disturbance that spawned Sandy, seen here on October 20, 2012, was quite large.

2) High relative humidity in Sandy's genesis region
The amount of moisture in the atmosphere may play an important role in how large a hurricane gets (Hill and Lackmann, 2009.) Sandy was spawned in the Caribbean in a region where the relative humidity was near 70%. This is the highest humidity we saw during 2012 during the formation of any Atlantic hurricane.

3) Passage over Cuba
Sandy struck Cuba as an intensifying Category 2 hurricane with 110 mph winds. While the core of the storm was over Cuba, it was cut off from the warm ocean waters surrounding Cuba. Most of Sandy's large circulation was still over the ocean, though, and the energy the storm was able to extract from the ocean went into intensifying the spiral bands over water. When Sandy's core re-emerged over water, the hurricane now had spiral bands with heavier thunderstorm activity as a result of the extra energy pumped into the outer portion of the storm during the eye's passage over land. This extra energy in the outer portions of Sandy may have enabled it to expand in size later.

4) Interaction with a trough of low pressure over the Bahamas
As Sandy passed through the Bahamas on October 25, the storm encountered strong upper-level winds associated with a trough of low pressure to the west. These winds created high wind shear that helped weaken Sandy and destroy the eyewall. However, Sandy compensated by spreading out its tropical storm-force winds over a much wider area. Between 15 and 21 UTC on October 25, Sandy's area of tropical storm-force winds increased by more than a factor of two.

5) Leveraging of the Earth's spin
As storms move towards Earth's poles, they acquire more spin, since Earth's rotation works to put more vertical spin into the atmosphere the closer one gets to the pole. This extra spin helps storms grow larger, and we commonly see hurricanes grow in size as they move northwards.

6) Interaction with a trough of low pressure at landfall
As Sandy approached landfall in New Jersey, it encountered an extratropical low pressure system to its west. This extratropical storm began pumping cold air aloft into the hurricane, which converted Sandy into an extratropical low pressure system, or "Nor'easter". The nature of extratropical storms is to have a much larger area with strong winds than a hurricane does, since extratropical storms derive their energy from the atmosphere along a frontal boundary that is typically many hundreds of miles long. Thus, as Sandy made landfall, the hurricane's strongest winds spread out over a larger area, causing damage from Indiana to Nova Scotia.

Are we likely to see more such storms in the future?
Global warming theory (Emanuel, 2005) predicts that a 2°C (3.6°F) increase in ocean temperatures should cause an increase in the peak winds of the strongest hurricanes of about about 10%. Furthermore, warmer ocean temperatures are expected to cause hurricanes to dump 20% more rain in their cores by the year 2100, according to computer modeling studies (Knutson et al., 2010). However, there has been no published work describing how hurricane size may change with warmer oceans in a future climate. We've seen an unusual number of Atlantic hurricanes with large size in recent years, but we currently have no theoretical or computer modeling simulations that can explain why this is so, or if we might see more storms like this in the future. However, we've seen significant and unprecedented changes to our atmosphere in recent decades, due to our emissions of heat-trapping gases like carbon dioxide. The laws of physics demand that the atmosphere must respond. Atmospheric circulation patterns that control extreme weather events must change, and we should expect extreme storms to change in character, frequency, and intensity as a result--and not always in the ways our computer models may predict. We have pushed our climate system to a fundamentally new, higher-energy state where more heat and moisture is available to power stronger storms, and we should be concerned about the possibility that Hurricane Sandy's freak size and power were partially due to human-caused climate change.

References
Emanuel, K. (2005). Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436(7051), 686-688.

Hill, Kevin A., and Gary M. Lackmann (2009), "Influence of environmental humidity on tropical cyclone size," Monthly Weather Review 137.10 (2009): 3294-3315.

Knutson, T. R., McBride, J. L., Chan, J., Emanuel, K., Holland, G., Landsea, C., ... & Sugi, M. (2010). Tropical cyclones and climate change. Nature Geoscience, 3(3), 157-163.

Rotunno, R., & Emanuel, K. A. (1987). An air–sea interaction theory for tropical cyclones. Part II: Evolutionary study using a nonhydrostatic axisymmetric numerical model. J. Atmos. Sci, 44(3), 542-561.

The Atlantic is quiet, but a Nor'easter expected next week
The Atlantic is quiet, with no threat areas to discuss. An area of low pressure is predicted to develop just north of Bermuda on Wednesday, and the GFS model predicts that this low could become a subtropical cyclone as moves north-northeastwards out to sea late in the week.

The long-range models are in increasing agreement that a Nor'easter will develop near the North Carolina coast on Sunday, then move north to northeastwards early next week. High winds, heavy rain, and coastal flooding could affect the mid-Atlantic coast and New England coasts next Monday and Tuesday due to this storm, but it appears likely that the Nor'easter will stay farther out to sea than the last Nor'easter and have less of an impact on the region devastated by Sandy. Ocean temperatures off the coast of North Carolina were cooled by about 4°F (2.2°C) due to the churning action of Hurricane Sandy's winds, but are still warm enough at 22 - 24°C to potentially allow the Nor'easter to acquire some subtropical characteristics. I doubt the storm would be able to become a named subtropical storm, but it could have an unusual amount of heavy rain if it does become partially tropical. The Nor'easter is still a long ways in the future, and there is still a lot of uncertainty on where the storm might go.

Jeff Masters

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Quoting TropicalAnalystwx13:

So you'd rather have a blog with people talking about something set in stone all the time? That's no fun. Of course people are going to be about certain aspects of global warming; it's a debatable topic. That doesn't mean we should just ignore the topic at hand.
It makes me chuckle every time someone brings up the global warming and climate statistics and then posts that it is off topic...
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting AussieStorm:
When are some guy on here going to grow some "wheels" and grow up, geez. this blog is worse than a pre-school class just before nap time.

Why do we like to argue about the same stuff here. every time AGW/CC comes up we hear the same things over and over again. PEOPLE..... grow the heck up. If you want to argue and trade silly school yard insults, do it elsewhere.

There will always be 2 sides to every argument and until either side backs down, the argument will continue forever.

So you'd rather have a blog with people talking about something set in stone all the time? That's no fun. Of course people are going to be about certain aspects of global warming; it's a debatable topic. That doesn't mean we should just ignore the topic at hand.
Member Since: Posts: Comments:
Quoting SherwoodSpirit:


I'm pretty sure you just fed a troll with this answer, because the answer is so obvious, and it was such a silly question ("I wanna be prepared" riiiight).
But whatever. Keep fightin' the good fight Neapolitan. :)


Nonetheless, it brings a thought to my mind....Greenlands glaciers will be a great loss of fresh water into the salt water oceans. Maybe Greenlands government should start working with other governments, to do something to start transporting what they can to areas that can hold the fresh water or such. They always say water will someday be like gold. Might even make Greenland, or other places with melting glaciers, a bit extra money. Seems silly to just let all that fresh water go to salty waste, when water is so precious in many places. Seems like something could be done?!
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Quoting hydrus:
That tree is gifted..It should apply at the NHC.

It tried and was turned down.
They couldn't deal with the way it keeps branching out, avoiding the roots of the issues. Also, it's very green, and it leaves people confused and scared.
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Quoting luvtogolf:

Interesting comments pulled from an article from Joe Bastardi regarding Sandy.

Joe
Bastardi,
denier
of
basic
climate
science.
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Quoting TomballTXPride:

I think some would be better off just accepting the fact that they are likely not going away anytime soon, whether or not it's having an impact on the climate or not.
I do agree on this. ;)
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804. wxmod
For a long time major earthquakes were mostly in the Asia Pacific and Indian Ocean. Now it's our turn. There is a lot of pressure building on the San Andreas Fault.

Member Since: Posts: Comments:
When are some guy on here going to grow some "wheels" and grow up, geez. this blog is worse than a pre-school class just before nap time.

Why do we like to argue about the same stuff here. every time AGW/CC comes up we hear the same things over and over again. PEOPLE..... grow the heck up. If you want to argue and trade silly school yard insults, do it elsewhere.

There will always be 2 sides to every argument and until either side backs down, the argument will continue forever.
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Quoting pottery:
My Calabash tree says that 2012 Hurricane Season is finished.
It also says that there will be winter storms in North America over the next couple of months, and that the weather will be fair to foul with a chance of disparaging remarks leading to stuff and whatnot.

Just sayin'.....
That tree is gifted..It should apply at the NHC.
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting TomballTXPride:
I love it when those on here bash Joe B. for his take on history vs. hurricanes and then praise Jeff Master's and the others who have their take.

Could it have something to do with how they conform to their green-energy GW approach? Hmmm...

Last time I checked Jeff Master's isn't any more a climatologist than Joe Bastardi is....
I find Joe Bastardi to be very knowledgeable on many weather fronts ( forgive the pun ). People tend to pick on him because he can be abrasive at times, but he does know his stuff. He did not keep his job at AccuWeather for 100,000 years because of the lack of knowledge on the subject. No you are not bothering me..:)
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting TomballTXPride:

What evidence did he deny? I did not see anything like that tonight. He simply presented a piece like many others have been doing tonight regarding the topic of the blog.


He is a global warming denier (or at least, he denies human caused climate change -- I do not have sufficient knowledge of his position to make the claim that he outright denies all warming), which is fine; skepticism is good, it's how science has evolved to where it is today. However, skepticism needs to be well-founded (i.e., grounded in evidence, not stubbornness). Thus far, I haven't seen Doug present any compelling evidence (or any evidence at all) that anthropogenic global warming is not occurring.

Now I'll admit that his comment toward me may not have been the result of him denying AGW proponents, but it very well could have. That's why I called it "implicit".
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Quoting Neapolitan:
If the earth were rapidly cooling--which it most definitely is not--the one proven method by which we could warm it back up just as rapdily would be to synthesize and pump more than 3.4 million metric tons of CO2 into the atmosphere every hour of every day. There's virtually no doubt among scientists that that has, and would, do the trick....


Point is, neither you nor anybody else is going to change cooling or warming trends. The cry should be for cleaner air and water and that's done with strict enforcement and very harsh penalties for companies that willfully violate those regulations. When the company I work for has some type of accidental release(usually ethylene) we immediately notified the state's enviormental authorities even though most of those were very small. Technologies of the future will solve many of our pollution problems. You enjoy your current standard of living because of fossil fuels and like it or not they are here to stay. Not to mention these energy jobs are some of the best paying jobs.

When the sun can be positively ruled out as having no connection with the cooling or warming of this planet then I'm in the "jury is still out" category. Have a nice day.
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My Calabash tree says that 2012 Hurricane Season is finished.
It also says that there will be winter storms in North America over the next couple of months, and that the weather will be fair to foul with a chance of disparaging remarks leading to stuff and whatnot.

Just sayin'.....
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AAAFFFFGHTHWEHRWHeraSDFWIERNAFDOGADCMS{@HIRWNQDSFAW IR



^^This comment is about as useful as half the other comments on here......good night...
hopefully by tomorrow everybody is in a better mood....
Member Since: February 11, 2012 Posts: 0 Comments: 9756
Quoting AussieStorm:

oh snap. lol

Kori, are you pretending to be a meteorologist? Are you a Meteorologist?


I will happily admit that I do not have any academic credentials identifying me as a meteorologist of any sort. I am just an avid weather watcher who has been making personal forecasts for the last four years. I miss some, while others I nail quite accurately. Just the name of the game ladies and gentlemen.
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Quoting TomballTXPride:
I love it when those on here bash Joe B. for his take on history vs. hurricanes and then praise Jeff Master's and the others who have their take.

Could it have something to do with how they conform to their green-energy GW approach? Hmmm...

Last time I checked Jeff Master's isn't any more a climatologist than Joe Bastardi is....


And of course when Bastardi forecasts a hurricane that will impact the US and not go out to sea, 95% of the blog loves Bastardi and will post his tweets and forecasts until the cows come home. Bastardi does have some good points about the pattern in the 1950's. Here is the write up he did back in July.

Link
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Quoting AussieStorm:

But it's over all size was very large.


I was speaking of wind radii, though. I assumed you were as well. Sorry for the misunderstanding.

Though that does create an entirely different conundrum, doesn't it? Discovering the statistically largest circulations for horizontal extent would be quite challenging, since I'm not sure any records are really tabulated to that effect.
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Quoting ncstorm:


international rates do not apply..

so that number again is 20122012.
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Quoting AussieStorm:

What's the international number for that please. lol


international rates do not apply..
Member Since: August 19, 2006 Posts: 13 Comments: 16222
Quoting TomballTXPride:

Why is it a useless endeavor with Doug?


Because I've seen him deny evidence numerous times. The most recent occasion? His childish insult to me (granted that wasn't explicit, but as adults surely we are able to distinguish between an implicit claim and an explicit one?).
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The GFS still wants to keep the Eastern Seaboard stormy and cold.
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting KoritheMan:


I dunno. Ernesto had a 35 kt wind radii of less than 200 miles at its largest. Not sure I'm comfortable labeling that as "unusually large".

But it's over all size was very large.
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784. wxmod
In an interview on climate change Al Gore said:

"I watched Ahmedinejad last night or maybe it was the night before last on one of the interview shows on CNN and he was asked if he believes the Holocaust was a historical fact and he said: 'Why are you against debating the truth. We need more research. We need investigators to go and look at the evidence'."
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Quoting ncstorm:
Just text SAVETHEBLOG to 12212012 to donate weather comments

Your help is much appreciated and needed!

What's the international number for that please. lol
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Quoting PensacolaDoug:


Maybe you oughta stop pretending to be a meteorologist.


EDIT for spellimg

oh snap. lol

Kori, are you pretending to be a meteorologist? Are you a Meteorologist?
Member Since: Posts: Comments:
Just text SAVETHEBLOG to 12212012 to donate weather comments

Your help is much appreciated and needed!
Member Since: August 19, 2006 Posts: 13 Comments: 16222
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Quoting TomballTXPride:

Once again, I did not quote you, nor did I make specific mention of you. If you would like to find another person to WU email, please do so. I don't like emails.
We have WU-Mail to avoid posts like this.
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting hydrus:
I have your back on that..You never skirt the truth or the facts when presented with them in a honorable way. It is a good quality in my honest opinion.


Thank you hydrus. I definitely wasn't including you in the list of myopic people in this world. :)
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774. wxmod
Quoting GeorgiaStormz:
And nobody says anything they've never said before and nobody is changing anybody's mind.


That's the way all blogs are.
Why do you suppose that is?
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Quoting AussieStorm:

Would you add to that list TS Debby and Hurricane Ernesto? Both of them were larger size category.


I dunno. Ernesto had a 35 kt wind radii of less than 200 miles at its largest. Not sure I'm comfortable labeling that as "unusually large".
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Quoting KoritheMan:

Believe it or not, some people ARE open-minded enough to change their positions when presented with actual evidence. Unfortunately, not many people here or elsewhere fit that bill. A lot of myopic people exist in this world.
I have your back on that..You never skirt the truth or the facts when presented with them in a honorable way. It is a good quality in my honest opinion.
Member Since: September 27, 2007 Posts: 1 Comments: 22580
Quoting KoritheMan:


Apparently flooding in some neighborhoods in and around Laplace was comparable to Katrina. That being said, Isaac's areal damage was much more localized, and I'm still of the opinion that it doesn't merit retirement. Sandy is a different kettle of fish.

ETA: Though if you were talking about size, then yes, we can add Isaac to the growing list of unusually larger Atlantic tropical cyclones.

Would you add to that list TS Debby and Hurricane Ernesto? Both of them were larger size category.
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770. wxmod
A quote from an interview with Al Gore:

"Every single news programme in the United States on television with one exception - Current TV [which was founded by Gore] does not accept their money - but every other network, all of the commentary programmes and news programmes, are sponsored generously by the coal, oil and gas companies. And every viewer who is interested in the political dialogue or the workings of democracy is bathed in a constant shower of misleading propaganda ..."

link:
http://www.guardian.co.uk/environment/2012/nov/14 /al-gore-climate-change-transcript?intcmp=122
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Quoting TomballTXPride:

Someone is a little sensitive.
If I were sensitive, I could come up with a much better approach than this. Trust me.

I don't waste my time on people like Doug, though. Experience has shown it's a useless endeavor.
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Quoting GeorgiaStormz:
So FOUR HOURS later and this blog is still embroiled in some type of civil war.....or maybe its uncivil war.

ugh. And nobody says anything they've never said before and nobody is changing anybody's mind. I actually see why people leave here.
Believe it or not, some people ARE open-minded enough to change their positions when presented with actual evidence. Unfortunately, not many people here or elsewhere fit that bill. A lot of myopic people exist in this world.
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765. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #11
TROPICAL DEPRESSION 26
9:00 AM JST November 15 2012
=======================================

SUBJECT: Tropical Depression In South China Sea

At 0:00 AM UTC, Tropical Depression (1008 hPa) located at 9.3N 107.8E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving north northwest slowly.

Dvorak Intensity: T2.0

Forecast and Intensity
========================
24 HRS: 9.7N 104.5E - 35 knots (CAT 1/Tropical Storm) South China Sea
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764. beell
Quoting MrMixon:
#754:



wikipedia puts it well
:

"...to create the illusion of having refuted a proposition by replacing it with a superficially similar yet unequivalent proposition."


Could you remind me what the original proposition was again?
TIA
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So FOUR HOURS later and this blog is still embroiled in some type of civil war.....or maybe its uncivil war.

ugh. And nobody says anything they've never said before and nobody is changing anybody's mind. I actually see why people leave here.
Member Since: February 11, 2012 Posts: 0 Comments: 9756
Quoting LargoFl:
If oceans continue to rise in the coming decades, the areas most likely to be under water are Pinellas, Monroe, Miami-Dade, Broward and Lee counties, said scientists who gathered Thursday for Florida Atlantic University's Sea Level Rise Summit.


Ahh I remember that event! It was in June, and I had to miss it for mid-terms (at FAU) I think.
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Quoting overwash12:
So,All the storms throughout history that raked the Eastcoast of the U.S.(and there have been some real doosies) were just natural weather patterns. Now they are all attributed to Climate Change! Interesting!


Quoting ncstorm:


You got it..

now head to the table with all the cherry flavored koolaid and ask your question again..be sure to drink it fast without thinking..


lol

Nea, do you have me on ignore????
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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