Extreme weather and climate change: a new IPCC report

By: Dr. Jeff Masters , 3:48 PM GMT on November 18, 2011

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Extreme weather events are already being affected by human-caused climate change, and will increase in destructive power during the coming decades as huge cost, reported the United Nations Intergovernmental Panel on Climate Change (IPCC) today. The IPCC issues reports on the state of the scientific knowledge of climate change every six years, with the next full report due out in 2013. However, concern over the possible impact climate change may already be having on extreme weather events like heat waves, floods, and droughts prompted the IPCC to release their first-ever Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). The SREX report was divided into two sections: how human-caused climate change has already affected extreme weather events, and predictions on how these events will change during the rest of the century. Here are some highlights on how the climate has already changed, according to the SREX report:

- Globally, cold days and nights have decreased, and warm days and nights have increased (90 - 100% chance).

- In many but not all regions of the globe, the length or number of heat waves has increased.

- Some areas have seen more intense and longer droughts, in particular, southern Europe and West Africa. However, droughts have become less frequent, less intense, or shorter in some areas, such as central North America and northwestern Australia.

- Heavy precipitation events have changed in some regions. There is at least a 2-in-3 probability that more regions have seen increases than decreases in heavy precipitation events.

- The historical data base on hurricanes and tropical cyclones is not good enough to tell if they have changed.

- The jet stream has shifted towards the poles, meaning that the tracks of rain-bearing low pressure systems have also shifted towards the poles.

- Rising sea levels have led to an increase in extreme coastal flooding events (66 - 100% chance).

- Damage from extreme weather events has increased. Increases in population and wealth, and the fact more people are living in vulnerable areas, is a major cause of this increase in damage. It is uncertain if climate change is partially responsible for the increase in damage.


Figure 1. Predicted return periods for 1-day extreme precipitation events that occurred, on average, only once every 20 years between 1981-2000. A decrease in return period implies more frequent extreme precipitation events (i.e., less time between events on average). For Eastern North America, a 1-in-20 year heavy rain event is predicted to become a 1-in-7 to 1-in-9 year event by the end of the century, according to these climate model predictions. The box plots show results for regionally averaged projections for two time horizons, 2046 to 2065 and 2081 to 2100, as compared to the late-20th-century, and for three different emissions scenarios--a scenario where humans emit relatively little CO2 and other heat-trapping gasses (B1, blue bars), and two higher-emission scenarios (A1B and A2, green and red bars). Humanity is currently on a pace to emit more CO2 than the highest emission scenario shown here. Results are based on 14 climate models that contributed to the 2007 IPCC report. The level of agreement among the models is indicated by the size of the colored boxes (in which 50% of the model projections are contained), and the length of the whiskers (indicating the maximum and minimum projections from all models). Values are computed for land points only. The “Globe” inset box displays the values computed using all land grid points. Averaged over all areas of the globe, a 1-in-20 year heavy rain event is predicted to become a 1-in-8 to 1-in-12 year event by the end of the century. Image credit: The IPCC Special Report on Managing the Risks of Extreme Events and Disasters (SREX), 2011.

Here are some highlights of the forecasts for the future from the 2011 SREX report:

- A 1-in-20 year hottest day is at least 66% likely to become a 1-in-2 year event by the end of the 21st century in most regions, except in the high latitudes of the Northern Hemisphere, where it is likely to become a 1-in-5 year event.

- For Eastern North America, a 1-in-20 year heavy rain event is predicted to become a 1-in-7 to 1-in-9 year event by the end of the century.

- For Eastern North America, a maximum high temperature that occurred only once every 20 years during 1980 - 2000 is predicted to occur between once every three years and once per year by 2100.

- Extreme high temperature readings that occur once every 20 years will increase by 1°C to 3°C (1.8°F - 5.4°F) by mid-21st century and by about 2°C to 5°C (3.6°F - 9°F) by late-21st century.

- It is at least 66% likely that the frequency of heavy precipitation or the proportion of total rainfall from heavy falls will increase in the 21st century over many areas of the globe. This is particularly the case in the high latitudes and tropical regions, and in winter in the northern mid-latitudes. There is medium confidence that, in some regions, increases in heavy precipitation will occur despite projected decreases of total precipitation in those regions.

- Heavy rainfalls associated with tropical cyclones are at least 66% likely to increase with continued warming, and the maximum winds will increase. The total number of these storms is likely to remain about the same or decrease.

- There is medium confidence that droughts will intensify in the 21st century in some seasons and areas. Southern Europe and the Mediterranean region, central Europe, Central North America, Central America and Mexico, northeast Brazil, and southern Africa are at particular risk.

- In some regions, the main driver for increased damages from extreme weather events will not be climate change, but increases in population and wealth and vulnerability.

Intoducing climatecommunication.org
For those of you seeking detailed information on the research linking extreme weather events to climate change, I recommend a new website dedicated to improving communication of climate change information to the public, media, and policy makers, climatecommunication.org. The group is led by Susan Joy Hassol, a veteran climate change communicator, analyst, and author known for her ability to translate science into English, making complex issues accessible to policymakers and the public. Climatecommunication.org has put together an overview of extreme weather and climate change that I find a helpful resource when I am looking for the latest research results on the subject. I serve on their advisory board, along with a number of leading climate scientists.


Figure 2. Still image of the Bangkok, Thailand floods of October - November, 2011, as seen on the inaugural episode our new bi-monthly Extreme Weather video series.

Wunderground launches new Extreme Weather video series
Wunderground now features a new, twice-monthly Extreme Weather video series from GREEN.TV, with the latest reports and analysis on extreme weather around the world. From droughts to hurricanes to blizzards to flooding, Extreme Weather will cover the story and the science behind the events to try to understand their causes and consequences. The Extreme Weather series is sponsored by Vestas, the world's leading wind turbine manufacturer. The inaugural episode, launched yesterday, features video of the great Thailand flood, destructive floods in Italy, the $3 billion Northeast U.S. snowstorm of October 29 - 30, the massive Bering Sea, Alaska blizzard of November 9, the Texas drought, and the launch of a new polar-orbiting weather satellite. Look for a new video every two weeks on our Climate Change Videos page.

Resources
For those of you who haven't seen it, my top "must-read" post of 2011 is called, 2010 - 2011: Earth's most extreme weather since 1816?. Back in June, I went through the ridiculous barrage of extreme weather events the planet saw in 2010 and early 2011, and concluded: But it is highly improbable that the remarkable extreme weather events of 2010 and 2011 could have all happened in such a short period of time without some powerful climate-altering force at work. The best science we have right now maintains that human-caused emissions of heat-trapping gases like CO2 are the most likely cause of such a climate-altering force.

Wunderground's climate change blogger, Dr. Ricky Rood, has some thoughtful observations on the communication of the extreme weather/climate change link published in earthzine magazine titled, Changing the Media Discussion on Climate Change and Extreme Weather.

Jeff Masters

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Quoting Some1Has2BtheRookie:


Hello, Grothar.

I see that you are honing your painting skills. Just remember that Pottery does not like you painting the yellows and reds around his area. ;-)


I heard he told the same thing to van Gogh!
Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting GeoffreyWPB:
Ugg...Doing my online X-mas shopping. Put in your requests now.


Good! Glad you stopped by. Uh, I will take a dose of sanity with a side order of patience. Rare, please. I will finish cooking it myself.
Member Since: August 24, 2010 Posts: 0 Comments: 4772
Kenneth is likely intensifying.

Link
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Ugg...Doing my online X-mas shopping. Put in your requests now.
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Quoting Grothar:


Hello, Grothar.

I see that you are honing your painting skills. Just remember that Pottery does not like you painting the yellows and reds around his area. ;-)
Member Since: August 24, 2010 Posts: 0 Comments: 4772
Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting Seastep:
Please, Scott, show me how it is not true that there has been no significant temp increase since 2000.

Are you asserting otherwise?
It's climate change, not 2000 to 2011 temperature change.

Try and take your own advice by using the "scientific method" for once. Embarrassing.

Quoting Seastep:
Bedtime.

Scientific method. Observe.
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Quoting ScottLincoln:


GCRs = galactic cosmic rays. Some research has suggested that galactic cosmic rays from the sun may help form clouds. But the mechanism by which this happens is not direct, and several things must happen.
1. GCRs must help form aerosols, then
2. The aerosols must grow to a size that is suitable as cloud-condensation nuclei
3. The condensation nuclei must then form cloud droplets.

Having condensation nuclei does not necessarily imply clouds will form. Some parts of the globe are saturated with nuclei, yet no clouds form due to insufficient moisture. Most GCRs also do not make it through the atmosphere.

The hypothesis is that increased cosmic rays lead to more cloud cover (cooling) and decreased cosmic rays lead to less cloud cover (warming). As one can see, several things must line up for this to work for clouds in a particular area, let alone the entire globe. It should also be noted that studies have shown very little trend in GCRs over the last several decades, and the slight trend found in some studies has actually been toward more GCRs (cooling) - the opposite of what would be required to cause the observed temperature changes.
http://www.skepticalscience.com/a-detailed-look-a t-galactic-cosmic-rays.html

For GCRs to be the dominant driver of climate change over the last several decades, proving the GCR mechanism would not be enough. One would also have to invalidate multiple lines of evidence from up to a century of research showing that greenhouse gases regulate the earth's temperature, and the dominant driver of climate today is greenhouse gases.
Thanks Scott, haven't heard of the GCR thing before
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Good Night everyone, 99L is giving me a headache.
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Quoting Snowlover123:
I have never heard anyone claim that warming temperatures would LOWER the Dew Point. Could you explain the mechanism in order for this to occur?
You haven't?

I suppose that claim is not entirely true, but the basic concept is a warmer atmosphere can hold more water, therefore when the atmosphere is warmer, relative humidity drops and so do dew points. The reason why this isn't necessarily true, however, is that when the atmosphere is warmer more evaporation occurs putting more water in the atmosphere.
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Lower-Level winds

Upper Level winds

Shear Tendency
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Quoting Seastep:
This will come back to bite, imo, and is saved. All periods are about 6-10 years. Pay special attention the the last one.

Anyone nervous? ;)

If the trend continues for 30-40 years?

We will find out and there is no rush. The perceived/created rush is the main, general, problem in getting an intellectually honest discussion on the matter.


Why in the world would I be worried if temperatures leveled off or even dropped slightly in the next 30-40 years?

...I'd be glad if anything.

No one ever claimed they know the future, all we have right now are climate models which are currently predicting that we will continue to warm. What we can say is that we have been warming and contributing.
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Quoting SPLbeater:


maybe cuz the environment around it has become less conducive? NHC did mention 'marginal' conditions, so that might be it

Subtropical Storms can develop even when there's high shear.
Member Since: Posts: Comments:
649. j2008
20/2345 UTC 23.6N 52.5W EXTRATROPICAL 99L -- Atlantic
Well this is a new development.......so it went from STS to TOOWEAK and now to EXTRATROPICAL, I guess 99 wants to visit all the types.
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Quoting TropicalAnalystwx13:

No it isn't.
your right. i hadnt looked at it other then the categorical outlook. you showed the probabilistic outlook, for probability of seeing severe weather within a 25 MILE POINT. lol. sorry my bad there:)
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99L is in an area of about 20-40kt wind shear from the west...next few hours forecast to decline slightly. Mid-level shear aint no problem. Very dry air to its S, SW, W. othet then these things i dont see an issue with 99L. other then the 7 PM outlook needs changing to 50% lol
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Quoting SPLbeater:


thats the percentage forecast for wind damage u got there lol

No it isn't.
Member Since: July 6, 2010 Posts: 113 Comments: 32802
Quoting WeatherNerdPR:
Down to 40%. Strangely, it's convection has gotten deeper and it's center has become slightly better defined than earlier.

A LOW PRESSURE SYSTEM LOCATED ABOUT 700 MILES NORTHEAST OF THE
LEEWARD ISLANDS CONTINUES TO PRODUCE AN AREA OF SHOWERS AND
THUNDERSTORMS MAINLY TO THE NORTH AND EAST OF ITS CENTER. ALTHOUGH
THIS SYSTEM IS FORECAST TO STRENGTHEN AND PRODUCE GALE-FORCE WINDS
OVER THE NEXT COUPLE OF DAYS...IT IS MORE LIKELY TO BE FRONTAL IN
NATURE RATHER THAN TROPICAL OR SUBTROPICAL. THE LOW HAS A MEDIUM
CHANCE...40 PERCENT...OF BECOMING A TROPICAL...OR MORE LIKELY
SUBTROPICAL...CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
NORTH-NORTHEASTWARD AT 10 TO 15 MPH. ADDITIONAL INFORMATION ON
THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE
NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO
HEADER FZNT01 KWBC.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BERG


maybe cuz the environment around it has become less conducive? NHC did mention 'marginal' conditions, so that might be it
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Quoting Articuno:

You can say that again.

I don't like when Berg does the TWO.
Member Since: July 6, 2010 Posts: 113 Comments: 32802
Quoting TropicalAnalystwx13:

1.) I don't like when Berg does the TWO.
2.) I don't like when Berg does the TWO.
and 3.) I don't like when Berg does the TWO.

No clue what he is seeing, as it goes against the current situation the models' predictions.

You can say that again.
Member Since: Posts: Comments:
Quoting WeatherNerdPR:

What source is this? XD

Its from the 1970s, and the storm didn't come near land. So, the pressure was lower than indicated here, or the winds were lower than indicated here.
Member Since: July 6, 2010 Posts: 113 Comments: 32802
Quoting WeatherNerdPR:
Down to 40%. Strangely, it's convection has gotten deeper and it's center has become slightly better defined than earlier.

A LOW PRESSURE SYSTEM LOCATED ABOUT 700 MILES NORTHEAST OF THE
LEEWARD ISLANDS CONTINUES TO PRODUCE AN AREA OF SHOWERS AND
THUNDERSTORMS MAINLY TO THE NORTH AND EAST OF ITS CENTER. ALTHOUGH
THIS SYSTEM IS FORECAST TO STRENGTHEN AND PRODUCE GALE-FORCE WINDS
OVER THE NEXT COUPLE OF DAYS...IT IS MORE LIKELY TO BE FRONTAL IN
NATURE RATHER THAN TROPICAL OR SUBTROPICAL. THE LOW HAS A MEDIUM
CHANCE...40 PERCENT...OF BECOMING A TROPICAL...OR MORE LIKELY
SUBTROPICAL...CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
NORTH-NORTHEASTWARD AT 10 TO 15 MPH. ADDITIONAL INFORMATION ON
THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE
NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO
HEADER FZNT01 KWBC.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BERG

1.) I don't like when Berg does the TWO.
2.) I don't like when Berg does the TWO.
and 3.) I don't like when Berg does the TWO.

No clue what he is seeing, as it goes against the current situation the models' predictions.
Member Since: July 6, 2010 Posts: 113 Comments: 32802
Removed
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Quoting CybrTeddy:


Not as odd as Tropical Storm Omeka

Last year, formed on December 18th.. in the CPAC. Had an eye and everything.

Subtropical then tropical.


Yeah but the CPac does have a rep for oddities...but the EPac tends to stay in check.
Member Since: Posts: Comments:
Down to 40%. Strangely, it's convection has gotten deeper and it's center has become slightly better defined than earlier.

A LOW PRESSURE SYSTEM LOCATED ABOUT 700 MILES NORTHEAST OF THE
LEEWARD ISLANDS CONTINUES TO PRODUCE AN AREA OF SHOWERS AND
THUNDERSTORMS MAINLY TO THE NORTH AND EAST OF ITS CENTER. ALTHOUGH
THIS SYSTEM IS FORECAST TO STRENGTHEN AND PRODUCE GALE-FORCE WINDS
OVER THE NEXT COUPLE OF DAYS...IT IS MORE LIKELY TO BE FRONTAL IN
NATURE RATHER THAN TROPICAL OR SUBTROPICAL. THE LOW HAS A MEDIUM
CHANCE...40 PERCENT...OF BECOMING A TROPICAL...OR MORE LIKELY
SUBTROPICAL...CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES
NORTH-NORTHEASTWARD AT 10 TO 15 MPH. ADDITIONAL INFORMATION ON
THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE
NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO
HEADER FZNT01 KWBC.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BERG
Member Since: Posts: Comments:
Quoting WeatherNerdPR:

It'll still affect them, doesn't matter if it's warm or cold-core by the time it reaches them.
Also, lovemamatus is a troll. Ignore it before they think you're a troll for responding to his/her/it's comments.

My bad.
I just thought the "troll"'s sarcastic comment was funny.
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Quoting WeatherNerdPR:

What sorcery is this? XD


not a very reliable one... wikipedia
that just caught my attention
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Quoting trHUrrIXC5MMX:
how is this possible?

Hurricane Francene 1971
Duration July 18 %u2013 July 23
Intensity 115 mph (185 km/h) (1-min), 991 mb

What source is this? XD
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608 Seastep "If the trend continues for 30-40 years? We will find out and there is no rush.
The perceived/created rush is the main, general, problem in getting an intellectually honest discussion on the matter.
"

There's a grease fire on the stove. Will this trend continue through the kitchen to beyond? We will find out in 3-4 hours and there is no rush.
The perceived rush is the main, general problem in getting an intellectually honest discussion on the matter. Unfortunately, most folks would say it'd be smarter to smother the flames before the conflagration envelops the rest of their home.
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Quoting trHUrrIXC5MMX:
how is this possible?

Hurricane Francene 1971
Duration July 18 – July 23
Intensity 115 mph (185 km/h) (1-min), 991 mb


The environmental pressure around the storm must have been very high.
Member Since: September 6, 2007 Posts: 0 Comments: 6703
how is this possible?

Hurricane Francene 1971
Duration July 18 – July 23
Intensity 115 mph (185 km/h) (1-min), 991 mb
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This could be trouble in about a week..
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Quoting Articuno:

Well it is going out to sea..
Unless it hits the azores or something, but the water is way to cold for it to go all the way up there

It'll still affect them, doesn't matter if it's warm or cold-core by the time it reaches them.
Also, lovemamatus is a troll. Ignore it before they think you're a troll for responding to his/her/it's comments.
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Mid 80s and humid here, very warm autumn continues here
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Quoting lovemamatus:
Tammy is really starting to scare me. She looks potentially as dangerous as Jose.


Don't you mean Cindy, Franklin and Jose combined? That would be a disaster.
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Quoting lovemamatus:
Tammy is really starting to scare me. She looks potentially as dangerous as Jose.


Confirmed for trolling.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting lovemamatus:
Tammy is really starting to scare me. She looks potentially as dangerous as Jose.

LOL
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Quoting Tazmanian:




i wish you guys stop uesing the word fish storm fish storm is olny ues when it gos fully out too sea there may be ships in the way of this

Well it is going out to sea..
Unless it hits the azores or something, but the water is way to cold for it to go all the way up there
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Quoting Seastep:

Pay special attention the the last one.

Anyone nervous? ;)

You mean the one with the big drop in April/May 2010? The drop which is a based on only 47 stations, all in Antarctic.

It's called cherrypicking and is a well known tactic used by the deniers.

The tactic,

- Cherrypick a very small amount of data during which the short-term noise has dampened the long-term incline

- Ignore the long-term trend

- Refuse to examine the reasons behind the short-term change


Nervous? Are you? ;)
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Quoting CybrTeddy:


After 6 years, I still honestly couldn't tell ya..
I just noticed that..You have been posting here a long time. This next system might throw down some pretty rough stuff on Tuesday. I hope it is not too bad, we are still picking up from past storms in Middle Tennessee.
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Quoting interstatelover7165:
On a unrelated note, does anybody know how to copy & paste a still image from a youtube video?


After 6 years, I still honestly couldn't tell ya..
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Quoting interstatelover7165:
On a unrelated note, does anybody know how to copy & paste a still image from a youtube video?


Go into full screen mode. Press "Print Screen" on the keyboard (Prt Sc, Prnt Scr are the more common acronyms for it), load up Microsoft Paint (in the accessories section of the Start Menu program list), go into "Edit > Paste", and finally, save the picture.
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On a unrelated note, does anybody know how to copy & paste a still image from a youtube video?
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611 horsefeather "Does anyone know why chemtrails are being released from Air Force planes all over central Texas today?"

Contrails, not chemtrails
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Quoting wxgeek723:
I find it odd that the EPac pullled this off during a La Nina.


Not as odd as Tropical Storm Omeka

Last year, formed on December 18th.. in the CPAC. Had an eye and everything.

Subtropical then tropical.
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AL, 99, 2011112018, , BEST, 0, 232N, 532W, 25, 1009, LO,
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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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