I came across this fascinating article
EXTREME WEATHER FORENSICS
which makes a good attempt at explaining the link between global warming and extreme weather events
A question that many people including myself ask

EXTREME WEATHER FORENSICS
https://www2.ucar.edu/atmosnews/attribution/extreme-weather-forensics

An Extract from the article (Dole , Trenberth and Stott )
Research examples
DOLE
July temperatures across western Russia over the last century show large natural variability, but we cannot find evidence of climate trends during that period that would cause a heat wave on par with the disaster that struck Moscow in 2010. [research summary]
TRENBERTH
On average, the most intense rain events—like 2011’s Hurricane Irene across the mid-Atlantic—can be expected to produce 5–10% more rain than before, because there is up to 7% more water vapor in the air for every 1°C rise in temperature (4% for every 1°F). [research summary]

STOTT
It’s likely that the accumulation of human-produced greenhouse gases to date has at least doubled the odds of a heat wave in Europe as intense as the one in 2003, when tens of thousands of people perished. [research summary]


Thought it would be good to have a thread to discuss extreme weather events and some of the weather dynamics that caused the event generally and
global warming and links to extreme weather anomalies

The water vapour argument is only valid over the ocean and does not apply to continental rainfall - by similar reasoning the continents will be drier except where moisture transports occur from oceanic areas. (Trenberth, IPCC AR4, 2007). Trenbeth also is a moisture guy, so not sure if he is in a good position to comment on hurricanes (and we have already seen the reaction to his comments on tornadoes).

As crikey has created this thread on extreme weather I thought I should provide a few examples from the past.
So some extreme weather events in the UK from the 13th century at the height of the benign Medieval Warm period.
Of course if you want some examples of really extreme weather events then try the 1300 to 1399 period found here on Met index
And i should point out that this is just for England only without any reference to places on the continent or even Ireland and Scotland


1200-1219: (era) An exceptional series of great North Sea floods, mainly on the Dutch and German coasts. Great losses of land and people in the marshlands between Hamburg and Jutland. Some of these storm floods are believed also to have affected the English coast (almost certain I would have thought given the geography).

1201
& 1202 Two consecutive 'wet' years (but see end this entry). In 1201 specifically, the summer is thought to have experienced severe thunderstorms, notable hail in the London area - mid/late June (some sources have June 25th(OSP)).
In contrast to the foregoing, some sources have 1201 experiencing a notable "heat & drought" episode, but with no location details: harvest over on June 24th(OSP) in 1201 (where?); drought continued through July & August.
LWH

1203
(annual) A year of heavy rains in London. (Year not certain - might be one of the previous years, q.v.)

1204/05
(Winter) This winter was one of the severe winters of history and most rivers including the Thames were frozen completely; the frost prevented ploughing and all agricultural work was suspended from 14th January to 22nd March, the winter seed was destroyed and there was widespread famine.

1209 Old London Bridge built - because of its construction it allowed build-up of water up-river, particularly when debris clogged the gaps. Even without such problems, high water levels could lead to a significant difference between up-river & down-river sides: 'several feet' are mentioned. Conversely, tidal rise / fall was dampened by the bridge - decreasing the chance of tidal flooding above the bridge. However, the bridge increased the chance of fluvial flooding upstream. Bermondsey (London) is noted as having experienced flooding in this year.

1209/1210
(Winter) A severe winter. (Europe - Easton, in CHMW/Lamb). Severe frost in January and early February (London/South).

1212
(summer) A dry summer; a great fire in London.

1214
(summer) Another dry summer in which the Thames was so low in London that women and children could wade across it.

1216/1217
(Winter) A cold winter in western Europe / implied parts of Britain. (Easton, in CHMW/Lamb)

1218 Man killed by lightning at Stepney on 2nd February.
Severe thunderstorm with heavy rain on the 29th November.

1218/1219
(Winter) A cold winter in western Europe / implied parts of Britain. (Easton, in CHMW/Lamb)

18th October 1220 (or 1221) A violent northeasterly gale did much damage in London; the exact year/date is uncertain.

1222 Dry. Hot/dry summer in London/South.

1223 A very wet year with much flooding.

1224? A great drought in winter (of 1223/4 or 1224/5?: see also entry below.)

1224/25
or 1225/26
(Winter) A severe winter. (Easton, in CHMW/Lamb .. Ref. 1 .. 1224/25)
Severe Winter (London/South .. Ref. 8 .. 1225/26).
Difficult to know if these are the same events, with the year mis-attributed, or two events.

1230 St. Pauls damaged by lightning.
1232
& 1233 November (both years) - thundery (in a month that is not normally noted for thunderstorms inland). In 1232, London experienced 15 days of thunderstorms.

1233 Wet summer - heavy rains led to severe and widespread flooding over most of England. Severe thunderstorms on the 10th February [ accompanied by a 'gale' ] & thunder occurred on several days in November (see above). This sort of weather would have had major effects upon a mostly rural population, with possible famine, disease.

1233/34
(Winter) Long & severe frost from Christmas to 2nd February/Candlemas(OS) (London/South).

1235/1236
(Winter) A severe winter in western Europe / implied parts of Britain. (Easton, in CHMW/Lamb): this is suspiciously close to the event for 1233/34 .....

1236 Very heavy rain January to March: two floods in London in 1236. The first, which flooded Westminster Palace early in the year, was due to heavy prolonged rain.
The second was produced by a high (storm-surge) tide in November, drowned many people and a great number of cattle in the Woolwich area. An inundation in Norfolk by the sea destroyed flocks of sheep & herds of cattle, tore up trees and demolished houses. In one village alone about 100 people died. This must have been a major wind-driven event, caused by a violent depression, very low pressure & high winds.
However, the summer of this year was noted as dry/hot in London/South.

1237
(February) Heavy rains in February; the Thames flooded great stretches of the country (presumably roughly downstream of Oxford?).

1238
(Summer) Hot & dry. GPE

1240 Dry from January to March. (London/South).
(Spring,
Summer &
early Autumn) March - October, a prolonged drought. Dry/hot from 25th March(OSP) to 28th October(OSP). (London/South)

1242
(November) Heavy rain and thunderstorms on 19th November(OS) and on many days thereafter; the Thames flooded at Westminster & Lambeth.

1244 Dry autumn. (London/South).

1249 Gale on 28th October (London/South?).

1250
mid-1200's onwards Analysis of agricultural records of the time suggest that after the mid-1200's, harvests were increasingly subject to failures for various reasons (drought, cold/wet etc.).

October 1250 Major North Sea/English Channel storm/flood. Winchelsea on the Sussex coast suffered badly with 300 houses and a number of churches destroyed in a storm on the 1st October, 1250. More generally on this date, a major North Sea gale & sea flood caused great damage to adjacent parts of England, Holland & Flanders.(see also November 1570)

19th May 1251 Several houses in Windsor, including one occupied by the Royal Family ( Henry III ) were struck by lightning during a severe thunderstorm.

1252 & 1253 Both dry years - considered by some (e.g. Brooks), as the driest pair of consecutive years known in the record. The summer (& possibly the spring in London/South) of 1252 was outstandingly dry/hot, with the ensuing drought ruining crops & many people died from the excessive heat.
Spring/Summer 1253 was also noted as dry/hot London/South.

1252 & 1253
(Octobers) However (in contrast to entry above), significant flooding also occurred: the 1252 flood (in October) was due to heavy rain & the 1253 one (also in October) was tidal (storm-surge?).

1254 Severe frost January to March (London/South).

1255 Drought in spring & summer (London/South).

1256-1258 Three wet years .... extensive flooding, which led to harvest failures & high grain prices: shortage & starvation / distress for poor people.

1258
(June) June 24th(OSP), River Severn storm flood - many drowned. Not clear if this is heavy rain-water (i.e. a pluvial) event, or a wind-driven storm-surge event - hence no categorisation. LWH

1258 Notably cold/very wet overall: combination of cold/backward spring & heavy autumn rains gave rise to a very poor harvest. (see also above)

1259 Dry autumn (London/South).

1260
(Summer) Frequent & heavy thunderstorms during the summer produced hailstones with a diameter of about 5 cm (2 inches).
However, as often noted with such phenomena, there was a 'drought' in the summer London / South - this is not necessarily counter-intuitive as there are many cases of dry seasons throwing up localised severe storms.

1261 Frost/snow during February (London/South).

1264
(May) Gale on 13th May (London/South). [ It is just possible there is a link between this event and the one below .. but very unsure about this.]

1264
(between May & October) 1. Eleanor of Provence (Queen-Consort to Henry III) was frustrated by 'bad weather' (dates not known, but has to be late summer / early autumn 1264) in her attempt to bring troops to the aid of her husband's cause. The Queen's fleet was trapped by frequent spells of high wind at Sluis, Flanders (modern-day Netherlands, near the Belgian border) before it could cross to the Kent coast. According to Lamb, the 13th century experienced the highest number (by some margin) of "severe sea floods" along North Sea & English Channel coasts. Although the climate across NW Europe was still generally benign (indeed, the peak of warmth of the Medieval Age may have occurred in this century), from the middle of the 13th century, an increase in 'unsettled' weather events has been detected by some researchers; the first signs of the descent into the 'Little Ice Age'. It is indeed possible that the increased storminess was concentrated in the second half of the 13th century, so it was unfortunate that Eleanor attempted the passage of the Dover Strait at this time. (Lamb)

1269/70
(Winter) A bitter frost persisted for about 10 weeks during this severe winter; the Thames froze solid (thick enough for 'men & beasts' to cross over) and was closed to shipping, so that merchandise had to be transported overland between the Channel ports and London. Accounts of this winter included reference to glazed frost; the thaw, when it arrived, was accompanied by heavy rain and flooding. A flood on the Thames noted in February - presumably a combination of heavy rain / inland snow-melt etc., after the events referred to above.

1271 Gale; no date given. The bell tower of the church of St. Mary-le-Bow was blown down and killed several people. Also this year, from Norwich ecclesastical records a 'great flood' in this year, also lightning damaged the cathedral steeple.

1276 Dry from April to July (London/South).

1279
(May) England (location and exact date not known) ... severe thunderstorm, trees uprooted, buildings destroyed or flattened, lakes dried up (?). Possible T4 tornado event (could have been higher given those effects!)

1280 Considerable damage etc., across East Anglia due to floods & storms. (Norwich cathedral records).

October 1280 On the 9th(OSP), heavy snow fell in London. In modern-day dating, I suppose we're talking about mid-month, which would be remarkable in the 21st century.

1281/82
(Winter) During this notable winter, the frost (noted as a 'Great Frost' in contemporary records for January 1282) & snow persisted from Christmas to March; the Thames was frozen so hard that people could walk across the river (between Lambeth & Westminster certainly) and the force of the ice damaged five of the arches of London Bridge - some references say the arches 'collapsed'.

1282 (month not known, but after the snow above, and some reports of a 'destructive thaw' in this year, it would suggest sometime in early / mid-spring); Severe floods in 1282 when a great Gale brought much destruction & loss of life to Lincolnshire & East Anglia.

1283 Wet summer & autumn in London.

1285 Dry/hot summer (London/South).

1286
(May) 9th May, 1286 (corrected to new-style calendar) .. thunderstorm with large hail ('as big as stones'?). Crops levelled, houses damaged, branches of trees broken etc. Squally winds (and a possible tornado, but not certain - though the mention of the large hail tends to support mechanics available for such.)

1287 A 'terrible' indundation in the East Anglia (particularly Norfolk) coastal areas in December 1287 [probably due to a storm surge]. Houses destroyed, and in the village of Hickling the water was so deep that it overflowed the high altar of the priory by a foot or more. Some 500 people perished in this most fatal of all British floods.

[ The year 1287 is noted by Lamb [Ref. 23] as being one with 'many storm floods' along the East Anglian, Kent and Sussex (and adjacent continental) coastlines. ]

1288
(January) Tidal flooding on the Thames in January (but whether 1288 or 1289 is open to doubt).

1288
(Summer) Summer: dry/hot (London/South).

1288/89
(Winter) Severe winter (London/South).

1290 Wet summer & autumn in London.

1291 Dry summer London/South.

May 1294 On the 14th May(OS), heavy snow fell in London: the equivalent date in the modern calendar would be some 8 or 9 days later.

1294
(October) The Thames flooded Rotherhithe, Bermondsey, Tothill & Westminster on the 18th October(OSP). No details as to whether this is rainfall-related or a tidal surge.

We shoud also consider Australain events seeing as we live here.
Biggest rain events on record were in the 1890's.
Stongest cyclone is most likely 'Mahina' which produced a storm surge of up to 12M(nearly 3 times the height of 'Yasi'). Worst drought on record is either the one just gone or perhaps the federation drought.
1918 produced twin cat5 cyclones hitting the queensland coast(Innisfail and Mackay).
Also should consider that the last 30-40 years have actually been very quiet as far as extreme events go right at the time when they should have been more and more common and this trend has only been broken with the arrival of a strong Nina period.
Hottest temp recorded in australia 2nd jan 1960. Well before the real jump in warming took place.

Extreme weather events tend to happen in clumps. That connot be denied. In Australai these are obviousy related to ENSO and happen in moderately regular cycles. The strength of these clusters varies but overall they seem fairly uniform to me. TO be honest the ones I woud really like to get an answer on are the conditions during the 1890's and the twin cat 5 cyclones. Reason being if either of these events happened today both would be blamed on AGW but the fact is these events happened well before AGW would have had any effect on our weather. Explaining these events and finding a reason as to why they were so severe would go a long way to explaining many severe weather events.

That actually is very correct. For example - we have not had a cyclone crossing SEQ or Nth NSW since the 70's. This actually occurred quite regularly before. I think that in the 1890's Brisbane was affected by nearly a dozen cyclones - and some only a couple of weeks appart (1893).

Here are two 35 year periods worth of cyclone tracks. I think that we have got off easy in the last 30-40 years:

But...the oceans are warming, so we should be seeing more cyclones heading further south. How can it be? Bloody sceptic BOM!

Untill this month no floods on the Hawkesbury river since 1992

I agree with most of the above. The prime reason for my joining BoM in the early 60's and spending a few decades there was a school project relating to the 1893 Brisbane flood. And as my career continued there was more study in Qld based extreme events and in retirement these studies continue.

Part of the problem with the GW debate is that a whole generation has grown up without PERSONALLY experiencing many extreme weather events, such as the sudden quietening of TC activity since the mid to late 70's ( PDO shift ?? ) and being more or less that way till just recently when the PDO has shifted back again and more extreme events are once again occurring, so the current generation says " Gee-these things have not happened before ".

I go back to the 40's and my list of personal experiences is lengthy, from the 1954 TC Cat 2/3 crossing near Brisbane which wiped out local jetties.

Noting the continual flooding over much of the eastern half of the continent through the 50's,( highest solar max in history 1957 ).

Seeing ther Nerang River resume its natural entry to the sea in 1955 at where Narrow Neck now is( since filled in and a road is on top of it ).

Having to leave local theatre during a Saturday afternoon matinee as a storm surge associated with a passing TC caused Moreton Bay to spill across the Manly Esplanade and start entering the theatre in 1956.

Experiencing a tornado in Manly ( Dec 1960) which wiped out local shopping centre and Memorial Park, lifted a house off its stumps and dumping it in Cambrige Pde Manly, and caused grandstand at Manly pool to collapse into the said pool.

Saw a TC actually FORM off Caloundra Jan 1963 and hit the coast, another forming a year later in the same area.

Huge ECL in July 1965 off Brisbane causing a record 24 hour July rainfall and record lowest ever maximum temperature for Brisbane of only 11 degs.

Noted a satellite photo in March 1967 of 7 TC's active at once ( 3 in the Qld region - one in the Gulf, 2 off the coast ).

Later in 1967 - 3 ECL's in 2 weeks, the big one being over Queens Birthday weekend in June causing still to be broken 24 hour and many monthly June totals, the same ECL causing huge erosion in Surfers Paradise with the then surf life saving club at the end of Cavill Avenue being left on a sand island ( no high rises there yet ).

Watching the sea spill across the then Kirra caravan park across the then Pacific Highway and into Gilltraps Auto Museum during a TC in 1971.

Getting stuck driving the inland way to Melbourne through the Riverina with the Murray and tributaries in high flood in 1973-74 ( and happening again this year )- and the list goes on, including another Brisbane tornado in the Salisbury area in 1981.......but things then quietened down somewhat.

Now all of the above I have PERSONALLY experienced ( and much more ) througout that last " wet era ", and in more recent times in Townsville coinciding with the latest PDO shift - 6 straight above average wets ( with this year shaping up to be number 7 although not as big as others ), including record Feb rain in 2009, 2009/10 annual totals being either side of 2000mm. And of course Yasi which I went through.

Now the current generation, to which a lot of the recent happenings are new, as saying ' Haven't seen these things before-it must be GW..

And so on.

And to answer an earlier poster who commented on 3 TC's in the Brisbane area in 1893, ( an earlier one was there too in Dec 1892 ) the then highest barometric pressure in the world was recorded in eastern Russia in Dec 1892 which most likely contributed to a " super " monsoonal surge extending way further south that usual over the coming weeks and most likely contributed to the 3 TC's forming and their subsequent damages....

Sensational post RWM... thanks

Yeah, good post RWM.

The latest from the pro-AGW set is to ascribe all "normal" weather as global warming induced "normal" weather. If rain occurs or if it is sunny, it would not have happened without global warming.

More rain is global warming. Less rain is global warming. Perfectly normal amounts of rain is global warming.

Any "normal" conditions are abnormal now with global warming.

----

Obviously, this is Garbage.

And when garbage is thrown at you and your fellow citizens, day after day, you have a duty, as a citizen, to stop the garbage throwing. And this means everyone. Even if you ascribe to the more significant impacts of global warming - garbage is garbage. And it has to stop.

If something is truly abnormal, one can point that out. But what the pro-AGW set has been pushing for years is Garbage. Do they think we are imbeciles.

I'm tired of it to be honest.

I will be going after anyone who posts garbage from now on (and so should you all).

And speaking of Garbage.

I particularly don't like this quote in trying explain the reasons for our extreme weather:


No! It's consistant with La Nina and a PDO cold phase shift!

This is also laughable:


How can they predict so far into the future (even to the extent of the size of rain drops) when they cant predict even a month from now with any degree of meaningful accuracy?

Garbage!

There are things I don't like either about the way that certain alarmists keep getting invited to meetings of weather organisations as well as having their predilections published in the relevant journals.

I think I am a reasonable person but this preponderance of bias forced me to leave every such group of which I had been a member.

Trying to stay on topic here and keeping away from the pro/anti AGW debate which gets fought out on other threads I believe in this thread we should really focus on individual events and discuss what may or may not have contributed to those climatic phenomena. LLets try and pick what we believe to be an extrordinary event and work through it. Just an idea but if you lot are keen I think it coud be really interesting.

How about the 2005 run of hurricanes in the US?

So whats your argument?

I would prefer Australian events but OK.
Here is some info from Wikipedia on it.
The 2005 Atlantic hurricane season was the most active Atlantic hurricane season in recorded history, shattering numerous records. The impact of the season was widespread and ruinous with an estimated 3,913 deaths and record damage of about $159.2 billion. Of the storms that made landfall, five of the season's seven major hurricanes—Dennis, Emily, Katrina, Rita, and Wilma—were responsible for most of the destruction. The Mexican states of Quintana Roo and Yucatán and the US states of Florida and Louisiana were each struck twice by major hurricanes; Cuba, the Bahamas, Haiti, Mississippi, Texas, and Tamaulipas were each struck once and in each case brushed by at least one more. The most catastrophic effects of the season were felt on the United States' Gulf Coast, where a 30 ft (10 m) storm surge from Hurricane Katrina caused devastating flooding that inundated New Orleans, Louisiana and destroyed most structures on the Mississippi coastline; and in Guatemala, where Hurricane Stan combined with an extratropical system to cause deadly mudslides.

The season officially began on June 1, 2005, and lasted until November 30, although it effectively persisted into January 2006 due to continued storm activity. A record twenty-eight tropical and subtropical storms formed, of which a record fifteen became hurricanes. Of these, seven strengthened into major hurricanes, a record-tying five became Category 4 hurricanes and a record four reached Category 5 strength, the highest categorization for hurricanes on the Saffir-Simpson Hurricane Scale. Among these Category 5 storms were hurricanes Katrina and Wilma, respectively the costliest and the most intense Atlantic hurricanes on record. This year was also notable because the list of storm names was used up and six Greek letter names had to be used

How will we accurately account for Hurricanes in prior periods? And we know that 2005 was in a period where any swirl identified by satelite was given a tropical storm tag... For if we can't, the 2005 year may not be a record and really just a feature of the AMO cycle... And nothing special.


Consider:

There is a known relationship between the state of the AMO and Atlantic hurricanes:


There is a greater hurricane crossing in prior to satelite records:


We know that near the last peak of the AMO, there was a similar "extreme" years.
http://en.wikipedia.org/wiki/1950_Atlantic_hurricane_season
http://en.wikipedia.org/wiki/1933_Atlantic_hurricane_season

And in the previous peak as well
http://en.wikipedia.org/wiki/1887_Atlantic_hurricane_season

What makes us sure that we did not miss any tiny tropical (or sub tropical) storms during these years? The above suggest that we can't discount this. And hurricane experts like Chris Landsea resigned over the politicisation of the fact that science can't accurately count past hurricanes leading to inflation in modern (satelite) era.

So - over to you vpprt. What is special about 2005?

I dunno just throwing ideas out there.

Trolling?