91L no concern; more postcards from the AMS hurricane conference

By: Dr. Jeff Masters , 1:12 PM GMT on April 18, 2012

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I'm in Ponte Vedra Beach, Florida this week, where the world's hurricane experts are gathered to attend the 30th Conference on Hurricanes and Tropical Meteorology of the American Meteorological Society. Most of the Hurricane Specialists from the National Hurricane Center are here, and they are keeping an eye on the waters a few hundred miles east of Bermuda, where an extratropical storm has cut off from the jet stream and is slowly acquiring tropical characteristics. This system was designated Invest 91L last night by NHC. Ocean temperatures are around 20°C (68°F) in the region, which is well below the 26°C usually needed for a tropical storm to form. Wind shear is a high 20 - 30 knots. Nevertheless, 91L has managed to develop a small amount of heavy thunderstorm activity near its center, and may continue to show more organization as it moves slowly southeastward over the next day or two. I give 91L a close to 0% chance of becoming a named storm in the next two days, and NHC seems to have stopped issuing new products for the system. By the end of the week, 91L should get picked up by a trough of low pressure and move off to the northeast. The storm is not a threat to any land areas.


Figure 1. Morning satellite image of Invest 91L. The island of Bermuda is seen at the left side of the image.

Global tropical cyclones and climate: current signal
Now, I'll summarize a few of the excellent talks given at this week's AMS hurricane conference. Dr. Greg Holland of the National Center for Atmospheric Research talked about the impact of global warming on hurricane intensities. Using data beginning in 1975, the beginning of the satellite era, he showed that while the total number of hurricanes globally has decreased in recent years, the proportion of hurricanes that are of Category 4 - 5 intensity has increased by 40%. He showed that this change could be related to a 0.8°C increase in global temperature during the period. He concluded that when hurricanes form, they are finding that it is easier for them to reach higher intensities.

Sensitivity of the strongest hurricanes to ocean surface warmth
Dr. Jim Elsner of Florida State University showed that observations indicate a sensitivity of hurricane winds of 8.2 m/s +/- 1.19 per degree Centigrade of ocean warmth, using data in the Atlantic from 1981 - 2010 (for oceans areas warmer than 25°C.) Using a high resolution model (HiRAM) with 50 km resolution, a sensitivity of only 1.5 +/- .6 m/s was found, calling into question the usefulness of current models for assessing future hurricane activity.

How will climate change affect hurricane tracks?
Angela Colbert of the University of Miami used 17 global climate models, the BAM hurricane tracking model, and the Atlantic historical HURDAT data base to see how hurricane tracks might change in the future. She classified storms as either straight moving (which tend to hit the Caribbean or U.S. Gulf Coast), recurving landfalling (U.S. East Coast impacts), or recurving ocean storms that miss landfall. She projected a 6% increase in recurving ocean storms and an 8% decrease in straight-moving storms by the end of the century, due to climate change. A decrease of 1- 2 storms per decade is predicted for the Caribbean and Gulf of Mexico, and an increase of 1 - 2 storms per decade in the waters of the mid-Atlantic, and along the East Coast of Florida. This occurs primarily because of an increase in westerly winds over the Central Atlantic, and to a lesser degree, an eastward change in genesis location closer to the coast of Africa. Both of these factors would tend to increase the number of recurving storms.

Jeff Masters

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Quoting nigel20:

Whats up Levi...i've been getting varying answers to what the highest wind gust on earth.. What is the highest official wind gust on earth?


Let me fill in fer Patrap here...

uh, er, try using google search, might help ya out.
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NOAA-16 Polar Orbiting Satellite View
High Resolution Picture Transmission (HRPT










Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting wxmojo:


There is a systematic alignment of regular Euclidian geometry to the boundaries and certain interior features of the weather satellite imagery. It's a fairly obvious matching using a minimal degree of observational skills.

The additional files on minus.com are too large or involved to post directly on this blog.
Well, as it so happens, I do possess "a minimal degree of observational skills"--and I'll be darned if I can see anything that looks like a 'curious agreement'.

As I've said before, if one randomly superimposes enough circles of varying size, and lines of varying angle, onto any image, some features of that image are sure to line up with those circles and lines. But there's no "systematic alignment" that I can see in the images you've created/linked to. If there is, I'd appreciate you pointing it out to us instead of simply telling us that anyone who's not blind can see it.
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Quoting jeffs713:

LOL. Now I need to clean off my desk from the Dr Pepper I almost choked on. Thanks Levi.


Hi Jeff, Has Lake Travis recovered from the drought as in some cases 14" to 15" have fallen in the Houston area so far this year? I know RitaEvac posted pics of the lake way down late last year so I was wondering if it's back to normal now.
Member Since: October 26, 2011 Posts: 0 Comments: 2651
Quoting Levi32:


It's called the jetstream.

Whats up Levi...i've been getting varying answers to what the highest wind gust on earth.. What is the highest official wind gust on earth?
Member Since: November 6, 2010 Posts: 12 Comments: 8489
Quoting presslord:
...and there are thousands of little universes coexisting at the tip of my left ring finger...

Stars That Play with Laughing Sam's Dice?
Weather mystics might be a feature of the future.
Or the future of the feature.
All we need now is a crystal ball with a few random lines drawn on it and we could initiate a whole new religion.
The Great Anti-Cyclonic Revival Movement, ( Cyclonic if you are South of the Equator.)
Fortunately we don't have that bleater on here anymore.
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first 'poof' of 2012! the season is starting early!
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Quoting wxmojo:


So the jetstream is perfectly circular according the polar satellite imagery? Cool. Who knew?


Sometimes it is at the poles
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Quoting Levi32:


It's called the jetstream.


So the jetstream is perfectly circular according the polar satellite imagery? Cool. Who knew?
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Quoting JNCali:
I'd be happy with just an accurate 72 hour forecast?!
My forecast for Florida this weekend is an 80% chance of oxycontin with pockets of heavy meth.
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Quoting wxmojo:


There is a systematic alignment of regular Euclidian geometry to the boundaries and certain interior features of the weather satellite imagery. It's a fairly obvious matching using a minimal degree of observational skills.

The additional files on minus.com are too large or involved to post directly on this blog.
I'd be happy with just an accurate 72 hour forecast?!
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Is it me, or is wxmod and wxmojo the same person on two handles....?

Might be time for a:

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Quoting Levi32:


It's called the jetstream.

LOL. Now I need to clean off my desk from the Dr Pepper I almost choked on. Thanks Levi.
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OUCH!!

Member Since: October 26, 2011 Posts: 0 Comments: 2651
Quoting ncstorm:
So let me see if understand the blog...when you dont understand someone's concept, you insult them?


I'm sorry we're gonna have to ask you to leave, PressLord will lead the way, and we will have to burn you at the stake.
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Ahhhhh, is this the payoff?
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...and there are thousands of little universes coexisting at the tip of my left ring finger...
Member Since: August 13, 2007 Posts: 0 Comments: 10492
Quoting wxmojo:
In post 10, wxmod showed a weird convective(?) connection between China and Oregon. Curious of what was going on there, a correlation grid was created for the northern hemisphere. Really unusual things are occurring, esp. in eastern Europe. See: www.metoffice.gov.uk/satpics/latest_IR.html

A time sequence of additional polar images has been uploaded to askwhy333.minus.com.




It's called the jetstream.
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So let me see if understand the blog...when you dont understand someone's concept, you insult them?
Member Since: August 19, 2006 Posts: 13 Comments: 16225
Lots of meetings going on at NWS office here Melbourne regarding this weekends event. Here's Tampa's discussion.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
154 PM EDT WED APR 18 2012

LONG TERM (FRIDAY NIGHT-TUESDAY)...
MODELS REMAIN SIMILAR THROUGH THE LONG TERM PERIOD WITH THE
DEEPENING TROUGH FORECAST TO CUTOFF AS IT MOVES ACROSS THE DEEP
SOUTH OVER THE WEEKEND THEN OPENING UP AND LIFTING OUT ON MONDAY.
MEANWHILE AT THE SURFACE...AN AREA OF LOW PRESSURE IS EXPECTED TO
DEVELOP OVER THE LOWER MISSISSIPPI VALLEY SATURDAY AND TRACK EAST
ACROSS THE DEEP SOUTH DURING SUNDAY AND THEN NORTHEAST UP INTO THE
CAROLINAS ON MONDAY. THIS SCENARIO WILL BRING ABUNDANT MOISTURE
NORTHWARD INTO THE REGION ON BREEZY SOUTH TO SOUTHWEST WINDS AHEAD
OF A COOL FRONT LEADING TO THE BEST RAIN CHANCES WE HAVE SEEN IN
MANY WEEKS AND LATER FORECASTS WILL LIKELY NEED TO RAISE POPS EVEN
HIGHER AS TIMING AND LOCATION OF THE SYSTEM BECOMES MORE CERTAIN.
STILL LOOKS LIKE THE THREAT FOR SOME STRONG TO POSSIBLY SEVERE
STORMS WILL EXIST SATURDAY NIGHT INTO SUNDAY AS DECENT SHEAR AND
STRENGTHENING WIND FIELDS SETUP ACROSS THE REGION
. BY EARLY NEXT
WEEK THE SYSTEM WILL BE SHIFTING NORTHEAST AWAY FROM THE AREA WITH
HIGH PRESSURE BUILDING IN BRINGING SOME DRIER AND SLIGHTLY COOLER
AIR INTO THE REGION.



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Quoting Neapolitan:
can you please explain to the denser among us just where your correlation grids have any type of agreement with the underlying images, curious or otherwise?


There is a systematic alignment of regular Euclidian geometry to the boundaries and certain interior features of the weather satellite imagery. It's a fairly obvious matching using a minimal degree of observational skills.

The additional files on minus.com are too large or involved to post directly on this blog.
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Quoting nrtiwlnvragn:


In the paper Dr. Masters references above it bases the climate on this paper, which mainly discusses wind shear as the main cause.
Great resource.. here's one of the images:
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Quoting wxmojo:
In post 10, wxmod showed a weird convective(?) connection between China and Oregon. Curious of what was going on there, a correlation grid was created for the northern hemisphere. Really unusual things are occurring, esp. in eastern Europe. See: www.metoffice.gov.uk/satpics/latest_IR.html

A time sequence of additional polar images has been uploaded to askwhy333.minus.com.




Also if you look at a flat map and draw a cross on it, the center point is very close of where Jesus was born.
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Quoting PlazaRed:
Noting:-154. wxmojo
Geometry is not a normal feature of water! ( I can just hear the screamers,headhunters and the devout, disagreeing.)
Lay lines work on land but 'Lay sea lines,' take a lot more swallowing with or without a pinch of salt?
Weather works in 3 dimensions and has to contend with temperatures, shear and solar influences, to say the least.
Geometry has little to contribute to the organised chaos of sub tropical evolutions.
I am of course eager to be converted by any convincing evidence of aqua geometry.

Rainbow IR map with lots of circles and lines on it incoming in...
3...
2...
1...
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GFS, Euro, & CMC are all showing a very strong low in the North Central Gulf this weekend. Very strong system here on the Euro!

Member Since: October 26, 2011 Posts: 0 Comments: 2651
Noting:-154. wxmojo
Geometry is not a normal feature of water! ( I can just hear the screamers,headhunters and the devout, disagreeing.)
Lay lines work on land but 'Lay sea lines,' take a lot more swallowing with or without a pinch of salt?
Weather works in 3 dimensions and has to contend with temperatures, shear and solar influences, to say the least.
Geometry has little to contribute to the organised chaos of sub tropical evolutions.
I am of course eager to be converted by any convincing evidence of aqua geometry.
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Quoting hydrus:
If a storm is strong enough to punch a hole through the tropopause into the stratosphere, it is worth the extra attention. One Met described the gravity waves like dropping a rock into a pond or shooting one out of it, either way you get the rippling effect. They are a weird weather phenomenon indeed.
the patterns present themselves as undulating bores in certain conditions preceding warm front and dryline events.. such type of gravity waves can be seen is visible satellite imagery, and i even spot their impact on Nexrad noise. it's an entirely different mechanism from the g-waves you posted, but something to make note of on certain severe weather days with warm advection airfields coupled with directional shear.
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Quoting presslord:


Ah! Of course!! Now it all makes perfect sense!!!


You have now entered the Twilight Zone
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Quoting Neapolitan:
And I'm not picking on you, but--again--can you please explain to the denser among us just where your correlation grids have any type of agreement with the underlying images, curious or otherwise?

(Also, repeatedly spamming the forum with links to your external blog at minus.com is a really good way to run afoul of the admins; you may wish to dial that back a bit.)


if you reverse the images....you can make out the words "Helter Skelter"
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Quoting wxmojo:
In post 10, wxmod showed a weird convective(?) connection between China and Oregon. Curious of what was going on there, a correlation grid was created for the northern hemisphere. Really unusual things are occurring, esp. in eastern Europe. See: www.metoffice.gov.uk/satpics/latest_IR.html

A time sequence of additional polar images has been uploaded to askwhy333.minus.com.



Congratulations! You can draw circles and lines on a weather map, and then add really complex language in an attempt obfuscate that you actually just drew circles and lines on a weather map.

Quoting WxGeekVA:
Is it just me, or has everything turned into a conspiracy theory nowadays...?

Speaking of circles, lines and conspiracies...

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Quoting wxmojo:
I am not picking on you nor am I trying to detract from your insightful observations in post 73. I simply wish to show that the correlation grid concept has its curious agreement with weather features at more local physical scale with supercell activity.
And I'm not picking on you, but--again--can you please explain to the denser among us just where your correlation grids have any type of agreement with the underlying images, curious or otherwise?

(Also, repeatedly spamming the forum with links to your external blog at minus.com is a really good way to run afoul of the admins; you may wish to dial that back a bit.)
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Quoting presslord:


Ah! Of course!! Now it all makes perfect sense!!!
if anyone has a Clue about what that post attempts to state, do let me know!!!
i cannot seem to find Any relation to what Hydrus was posting, other that using the same pics...
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looks like the Euro and CMC are on the same page..for now..

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acid must be making a comeback...
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.
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Quoting RTSplayer:


That part is easy to explain.

If yo look at a SST map of the atlantic, such as on Satellite during peak hurricane season, the cold waters and winds from the north push the SST down on the eastern side of the Atlantic.

Under GW, since the poles would be warmer, the cooling effect would be weakened on the eastern side of ocean basins, which means that the water temperatures would become more in line with what you see on the western side of the basins.

In short, over the long term, the water temperatures in the Eastern Atlantic will rise faster than the water temperatures in the Western Atlantic.
Thanks RTS.. the process is simple, but the results could really suck.. What do you think GW is going to do to the westerly winds carrying the seed storms off Africa? If that intensifies we could see some mid ATL monsters
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Quoting presslord:


Ah! Of course!! Now it all makes perfect sense!!!


I think you should call George Noory.
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Is it just me, or has everything turned into a conspiracy theory nowadays...?
Member Since: September 3, 2011 Posts: 13 Comments: 3477
In post 10, wxmod showed a weird convective(?) connection between China and Oregon. Curious of what was going on there, a correlation grid was created for the northern hemisphere. Really unusual things are occurring, esp. in eastern Europe. See: www.metoffice.gov.uk/satpics/latest_IR.html

A time sequence of additional polar images has been uploaded to askwhy333.minus.com.


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12Z Euro running

Member Since: August 19, 2006 Posts: 13 Comments: 16225
April 17, 2011

April 17, 2012
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Quoting wxmojo:
1. Sorry for the long post. I am unskilled in creating animated gifs.

2. hydrus, I am not picking on you nor am I trying to detract from your insightful observations in post 73. I simply wish to show that the correlation grid concept has its curious agreement with weather features at more local physical scale with supercell activity.

3. In compressible flow aerodynamics, there exist so-called characteristic lines, which are acoustic disturbances aligned obliquely from the main flow. I do wonder if characteristic line theory can be somehow related to these correlation grids. But I see at least two problems with that approach: (a) atmospheric flows are primarily low Mach number incompressible; and (b) the possible existence of orthogonal corners would not be well supported by characteristic line theory. But I may be entirely wrong too.







Ah! Of course!! Now it all makes perfect sense!!!
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Quoting aerojad:
Related to climate change & increasing SSTs - is there a threshold that could be crossed this century where sub/tropical activity becomes more common in the Mediterranean Sea?

They won't have tropical waves to jump start development, but if storm tracks & strong westerlies retreat northward, could that increase the chances?

Writing from the point of view of a person who doesn't know what they are talking about here on this one but!
Here's having a go?
Unlike 'your gulf,' the Med doesn't have a nice round shape with lots of warm water pouring into if from the south and an abundant supply of winds from the East which might on an unfortunate bad year bring in inclement weather that's been transported across the Atlantic or been spawned in its midst!
The Med does not have predominantly warm winds blowing into it and of course there are no significant currents or any tides, There is a Nasty hot desert to the south which is vast to say the least in its area and also it has the hot dry peninsular of Iberia to its north in the western regions.
Added to all these woes, there are quite a lot of islands and appendages some of which have high mountains on them and particularly nasty volcanoes.
Sounds a bit like hell from an hurricanes point of view.
In spite of the odds being against a 'Medicane,' we nearly got one last year and I think that if the summer was ludicrously hot and drove up SSTs along with favourable winds then, who's to say? Maybe just maybe, south of France, West of Sardinia, North of Libya and slightly to the East of my house, there might just be enough area to maintain an anomaly that some might deem to be of the hurricane family.
I'll let you know if I see anything unusual; of course!
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Quoting aspectre:
442 RitaEvac: Some Himalayan glaciers actually growing, scientists find. Other areas melting.

The most likely reconciliation of the low-resolution GRACE measurements not jibing with the comparatively high-resolution measurements of easier-to-access glaciers is:
Warming keeps some moisture from dropping on lower elevation mountains, then that
extra some still in the air is carried to and drops on the higher elevation mountains.


It also depends on where the glaciers being measured are. Higher altitude glaciers are less susceptible to lower tropospheric warming and may even benefit overall from higher atmospheric moisture levels.

The general ice balance of glaciers is negative, and the rate of loss has been increasing. Not all glaciers are melting of course (and no is suggesting that they are), but the ones losing ice outnumber those gaining ice by a noticeable margin.
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Member Since: August 6, 2011 Posts: 4 Comments: 42267
Quoting RTSplayer:


That part is easy to explain.

If yo look at a SST map of the atlantic, such as on Satellite during peak hurricane season, the cold waters and winds from the north push the SST down on the eastern side of the Atlantic.

Under GW, since the poles would be warmer, the cooling effect would be weakened on the eastern side of ocean basins, which means that the water temperatures would become more in line with what you see on the western side of the basins.

In short, over the long term, the water temperatures in the Eastern Atlantic will rise faster than the water temperatures in the Western Atlantic.


In the paper Dr. Masters references above it bases the climate on this paper, which mainly discusses wind shear as the main cause.
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1. Sorry for the long post. I am unskilled in creating animated gifs.

2. hydrus, I am not picking on you nor am I trying to detract from your insightful observations in post 73. I simply wish to show that the correlation grid concept has its curious agreement with weather features at more local physical scale with supercell activity.

3. In compressible flow aerodynamics, there exist so-called characteristic lines, which are acoustic disturbances aligned obliquely from the main flow. I do wonder if characteristic line theory can be somehow related to these correlation grids. But I see at least two problems with that approach: (a) atmospheric flows are primarily low Mach number incompressible; and (b) the possible existence of orthogonal corners would not be well supported by characteristic line theory. But I may be entirely wrong too.





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Member Since: August 6, 2011 Posts: 4 Comments: 42267
Quoting JNCali:
"How will climate change affect hurricane tracks?
Angela Colbert of Florida State University used 17 global climate models..... A decrease of 1- 2 storms per decade is predicted for the Caribbean and Gulf of Mexico, and an increase of 1 - 2 storms per decade in the waters of the mid-Atlantic, and along the East Coast of Florida. This occurs primarily because of an increase in westerly winds over the Central Atlantic, and to a lesser degree, an eastward change in genesis location closer to the coast of Africa. Both of these factors would tend to increase the number of recurving storms.
"

What is the cause of the eastward change?


That part is easy to explain.

If yo look at a SST map of the atlantic, such as on Satellite during peak hurricane season, the cold waters and winds from the north push the SST down on the eastern side of the Atlantic.

Under GW, since the poles would be warmer, the cooling effect would be weakened on the eastern side of ocean basins, which means that the water temperatures would become more in line with what you see on the western side of the basins.

In short, over the long term, the water temperatures in the Eastern Atlantic will rise faster than the water temperatures in the Western Atlantic.
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Dr. Greg Forbes Torcon Index-added Friday

Wednesday April 18
All areas - less than 2

Thursday April 19
KS east - 2 to 3
MO west, north - 2 to 3
OK southwest - 2 to 3
OK north-central - 2 to 3

Friday April 21
AR southwest - 2 to 3
LA northwest - 2 to 3
TX east (east and north of San Antonio) - 2 to 3
Member Since: August 19, 2006 Posts: 13 Comments: 16225

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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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