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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AL, 99, 2011112018, , BEST, 0, 232N, 532W, 25, 1009, LO,
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
Does anyone know why chemtrails are being released from Air Force planes all over central Texas today?
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I find it odd that the EPac pullled this off during a La Nina.
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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.


Member Since: September 9, 2008 Posts: 6 Comments: 3414
Rock Hill Tornado Debris Found 20 miles away in Ballantyne
See more info at this site:
Link
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BULLETIN
TROPICAL STORM KENNETH ADVISORY NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP132011
100 PM PST SUN NOV 20 2011

...A RARE LATE SEASON TROPICAL STORM FORMS IN THE EASTERN PACIFIC...


SUMMARY OF 100 PM PST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...11.5N 105.6W
ABOUT 525 MI...845 KM S OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES
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Read the comment section also...

Global warming a hoax for political gain, Larry Bell tells Round Table
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Quoting TropicalAnalystwx13:
As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.



thats the percentage forecast for wind damage u got there lol
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Tropical Storm Kenneth

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Quoting Neapolitan:
Just four days away from Thanksgiving, and we've got a tropical storm in the Eastern Pacific, and a good candidate in the Atlantic. If the Atlantic storm gets classified, too, anyone know whether there has ever been an active named storm in both basins simultaneously this late into the year?




this 10 days too go
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
Just four days away from Thanksgiving, and we've got a tropical storm in the Eastern Pacific, and a good candidate in the Atlantic. If the Atlantic storm gets classified, too, anyone know whether there has ever been an active named storm in both basins simultaneously this late into the year?
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SHORT TERM FORECAST
NATIONAL WEATHER SERVICE RENO NV
1128 AM PST SUN NOV 20 2011

CAZ071-072-202100-
LASSEN-EASTERN PLUMAS-EASTERN SIERRA COUNTIES-
GREATER LAKE TAHOE AREA-
INCLUDING THE CITIES OF...PORTOLA...SUSANVILLE...WESTWOOD...
SIERRAVILLE...LOYALTON...SOUTH LAKE TAHOE...TAHOE CITY...
TRUCKEE...MARKLEEVILLE
1128 AM PST SUN NOV 20 2011

.NOW...
A NARROW BAND OF LAKE EFFECT SNOW HAS DEVELOPED NORTH OF LAKE
TAHOE THIS MORNING. THIS NEARLY STATIONARY BAND IS LOCATED BETWEEN
HALLELUJAH JUNCTION AND CARNELIAN BAY. SNOWFALL RATES OF 1 TO 2
INCHES PER HOUR ARE POSSIBLE UNDERNEATH THIS BAND. A SPOTTER ALONG
HIGHWAY 395 IN HALLELUJAH JUNCTION RECENTLY REPORTED 3 INCHES OF
NEW SNOW IN A 90 MINUTE PERIOD. MOTORISTS ALONG HIGHWAY 395 AND
INTERSTATE 80 SHOULD BE PREPARED FOR RAPID CHANGES IN VISIBILITY
AND SNOW COVERED ROADS
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
Quoting Snowlover123:

In his intitial analysis, Spencer used the least sensitive climate models, and the most sensitive climate models, so it is not cherry picking in any given way.

Quote Roy Spencer,

I view my job a little like a legislator, supported by the taxpayer, to protect the interests of the taxpayer and to minimize the role of government "

And all this time, we thought you were a scientist Roy. Weird.

Roy, PLEASE put your toy model down

I doubt he will!

Roy Spencer's six trillion degree warming

Wow. Now that's global warming!
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99L certainly looks like a near-tropical multi-vortex cyclonic low. Why are there nearly no discussions out there of vortex meteorology?!

Also, the fish-storm-versus-non-fish-storm-designation-categ ory argument is partly moot. 99L's extratropical low will likely affect the Azores, and offshoots of the greater cyclonic region will likely impact Europe, and later combine with a cross-Atlantic trough from the Caribbean to Sandanavia.



Here's the 12z GFS showing Tammy-B south of the Azores at 228h after Tammy-A tracks through the Azores at 72h.
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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


Uh...what? What part of "fully out to sea" could the path be that would have a zero percent chance of encountering a ship? Ships have very good weather avoidance radar and computers now and rarely get caught unawares by a storm of any kind. Atlantic shipping regularly travels through much worse storms than 99L is likely to ever be. Fish storm seems to be a reasonably good description of a tropical storm that has little to no chance of striking any land area.
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Quoting TropicalAnalystwx13:
As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.



Indeed. 99L is definitely of secondary importance right now compared to the SPC outlooks for those of us in the southern Plains and the South. So far, it looks like the best chance for spin-up tornados is in the ARK-LA-TEX region, but how fast the front travels compared to how much unstable air we have in place will make all the difference. Right now, the MLCAPE energy isn't too impressive, but we also have no warm air cap in place, which usually limits our lapse rates. Tuesday will be a nailbiter for sure.

BTW, we had a 75 yard wide tornado that had a path of .9 miles, and was on the ground for two minutes last Wednesday. For some reason, Birmingham NWS gave it an EF-1 rating, even though there was no major structural damage done and no injuries. I wonder what the record is for the shortest time on the ground for an EF-1 tornado?
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Quoting sar2401:


There lies the question. Whatever 99L develops into, it will be a fish storm. Before satellites, the only reports would have been from ships at sea, and the area that 99L is in has never been a heavily traveled shipping route. Even with ship reports, vigorous low pressure systems in the central and north Atlantic have never been rare as we head for winter. I suspect we'll see more of these late season storms, but only because satellites are showing us things we haven't seen before.




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
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
Slow day today...
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Quoting AstroHurricane001:
A strong-looking hybrid-subtropical near-TS strength 50% INVEST low in the open central Atlantic in mid-to-late November! This has to be a rare phenomenon, unless it was common when satellite technology was nonexistant.



Reminds me of TS Peter from 2003.



There lies the question. Whatever 99L develops into, it will be a fish storm. Before satellites, the only reports would have been from ships at sea, and the area that 99L is in has never been a heavily traveled shipping route. Even with ship reports, vigorous low pressure systems in the central and north Atlantic have never been rare as we head for winter. I suspect we'll see more of these late season storms, but only because satellites are showing us things we haven't seen before.
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This just in:

EP, 13, 2011112018, , BEST, 0, 114N, 1050W, 35, 1005, TS, 34, NEQ, 100, 0, 0, 0, 1012, 200, 100, 0, 0, E, 0, , 0, 0, KENNETH, M,
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Quoting Seastep:


There's quite a few in there. Looks like that one is being pulled in. Moving fast NNE.

Link

They seem to be rotating around a broader center, similar to Lee.
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Main circ appears to be around 24N/52.5W to me.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting AstroHurricane001:


Is that a naked swirl I see to 99L's south?


There's quite a few in there. Looks like that one is being pulled in. Moving fast NNE.

Link
Member Since: September 9, 2008 Posts: 6 Comments: 3414
I am going through Steelers withdrawal.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting WeatherNerdPR:


Is that a naked swirl I see to 99L's south?
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Thanks Astro.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
A strong-looking hybrid-subtropical near-TS strength 50% INVEST low in the open central Atlantic in mid-to-late November! This has to be a rare phenomenon, unless it was common when satellite technology was nonexistant.



Reminds me of TS Peter from 2003.

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20/1745 UTC 23.4N 53.1W TOO WEAK 99L -- Atlantic
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
Remains as TD13-E according to ATCF at 18z update.

EP, 13, 2011112018, , BEST, 0, 114N, 1050W, 30, 1005, TD
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Sorry about the late post. I see the convo has shifted.

Had missed that post before.

Carry on.

Don't have a link on this 'puter.

Warm core or cold with 99L?
Member Since: September 9, 2008 Posts: 6 Comments: 3414
Quoting TropicalAnalystwx13:

I'm jumping into this conversation for a second, and I may be dead wrong, but how is the past irrelevant? The past deals a lot with the future.


Irrelevant to testing the theory. Very relevant to constructing the theory. That is the stage we are in. Theory has been put forth, now we observe to see if it is a valid one.

If the predictions from 2000 verify as true, then it goes a long way towards solidifying the theory.

While some may accept a theory before it is tested, I do not.

And, as I've always said and all I put forth is just that. Do I lean a certain way? Sure. As others lean the other way. Do I outright discount either way? Nope.

Have to see if it verifies.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
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EP, 13, 2011112012, , BEST, 0, 105N, 1041W, 30, 1005, TD
Member Since: May 21, 2006 Posts: 5092 Comments: 115710
It's been raining on and off all day.
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Quoting TropicalAnalystwx13:

They split "Tammy" into two, and develop the split part into something. I don't know if they make it an STS/TS or an Extratropical low though. Many also show another subtropical storm developing from a low pressure area that moves off the coast in 7-10 days.
I think if something does split off from Tammy and become it's own entity It'll be an interesting way to get Vince?.My game os on right now.I'll be back later on today.
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Quoting WeatherNerdPR:

Thanks.
EDIT: Interesting, subtropical for 12-18hrs? We'll see, we could beat 2010.

I think we'll beat it regardless of whether or not whatever splits from "Tammy" develops.
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Quoting yqt1001:


850mb Theta would suggest it is a extratropical non-mesocale cyclone.

Edit: looking at the Theta a bit closer, it may be subtropical for 12-18 hours...

Thanks.
EDIT: Interesting, subtropical for 12-18hrs? We'll see, we could beat 2010.
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Quoting TropicalAnalystwx13:
As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.


Wow, pretty much all of Mississippi in it
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Quoting TropicalAnalystwx13:

They split "Tammy" into two, and develop the split part into something. I don't know if they make it an STS/TS or an Extratropical low though. Many also show another subtropical storm developing from a low pressure area that moves off the coast in 7-10 days.

Whatever it is, it hits the UK. Tammy stays the same strength starting from 60hrs through 168hrs.
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Quoting WeatherNerdPR:
Notice the low to the north of "Tammy", it split from the storm...Is it Vince? Or non-tropical?


850mb Theta would suggest it is a extratropical non-mesocale cyclone.

Edit: looking at the Theta a bit closer, it may be subtropical for 12-18 hours...
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Quoting WeatherNerdPR:

12Z GFS 24hrs:

48hrs:

72hrs:

Notice the low to the north of "Tammy", it split from the storm...Is it Vince? Or non-tropical?

No clue.
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Quoting TropicalAnalystwx13:
Many of the models continue to make "Tammy" a hurricane.

12Z GFS 24hrs:

48hrs:

72hrs:

Notice the low to the north of "Tammy", it split from the storm...Is it Vince? Or non-tropical?
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Quoting washingtonian115:
Wasn't the models protraying two storms to develope?

They split "Tammy" into two, and develop the split part into something. I don't know if they make it an STS/TS or an Extratropical low though. Many also show another subtropical storm developing from a low pressure area that moves off the coast in 7-10 days.
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Anybody have a answer for post 559.
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Many of the models continue to make "Tammy" a hurricane.
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Quoting WeatherNerdPR:

000
ABNT20 KNHC 201738
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
100 PM EST SUN NOV 20 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THERE HAS BEEN LITTLE CHANGE IN THE ORGANIZATION OF SHOWER AND
THUNDERSTORM ACTIVITY ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
ABOUT 600 MILES NORTHEAST OF THE NORTHEASTERN LEEWARD ISLANDS
DURING THE PAST SEVERAL HOURS. ENVIRONMENTAL CONDITIONS APPEAR
MARGINALLY CONDUCIVE FOR THE DEVELOPMENT OF THIS DISTURBANCE DURING
THE NEXT DAY OR SO AS IT MOVES SLOWLY NORTHWARD. THIS SYSTEM HAS A
MEDIUM CHANCE...50 PERCENT...OF BECOMING A SUBTROPICAL OR TROPICAL
CYCLONE DURING THE NEXT 48 HOURS.

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

$$
FORECASTER KIMBERLAIN


would this storm eventually affect the Azores
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Quoting TropicalAnalystwx13:
As some users have been advertising for a few days now, there could be a big Severe Weather/Tornado outbreak on Tuesday.


Likely this system will rear its head today.
SPC convective outlooks
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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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