Dr. Jeff Masters' WunderBlog

Afternoon, all. We are having some nasty weather here - have been since Sunday night - with heavy downpours and even some bouts of thunder/lightning. This is really weird wx for late February, when we are used to balmy breezes, sunny skies, and temps in the mid / upper 70s. I can't help but wonder what the summer will have in store, given the current patterns......

Quoting atmoaggie:

A rough day, certainly, but not quite in the level of the 1973 outbreak:

WOW! That was quite an outbreak!

A hurricane-spawned tornado boom
Cyclones striking Gulf Coast in recent years have generated more twisters that those that hit the region in the mid-20th century

Hurricanes and tropical storms striking the Gulf Coast region since 1995 have spun off more twisters than those that hit during the mid-20th century, mostly because the more-recent storms have been broader and therefore have covered more area, a new study suggests.

Most tropical storms and hurricanes trigger tornado outbreaks upon striking land, says Judith A. Curry, an atmospheric scientist at the Georgia Institute of Technology in Atlanta. And even though most cyclone-spawned tornadoes are weak, they can cause significant death and destruction: The 117 tornadoes associated with Hurricane Ivan’s landfall in 2004, for example, killed seven people, injured 47, and caused nearly $97 million in property damage. Now, an analysis by Curry and her colleagues reveals that landfalling cyclones have become more prolific tornado producers than they used to be.
http://www.sciencenews.org/view/generic/id/47284/title/A_hurricane-spawned_tornado_boom


http://en.wikipedia.org/wiki/File:NOAA_ACE_index_1950-2004_RGB.svg

103:

Couldnt that be because of higher population along the coastal areas?

Rough day for the golfers:


PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
141 PM EST WED FEB 24 2010

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

1235 PM HAIL PALM CITY 27.17N 80.27W
02/24/2010 E1.50 INCH MARTIN FL EMERGENCY MNGR

*** 2 INJ *** TWO GOLFERS INJURED BY HAIL AND BLEEDING
FROM HEAD HAIL SIZE ESTIMATED.

Quoting tornadodude:
103:

Couldnt that be because of higher population along the coastal areas?

Yes

Quoting tornadodude:
103:

Couldnt that be because of higher population along the coastal areas?

Many factors. Back than they had not the information/media emergency bulletins and buildings might have been not that good.

Quoting drg0dOwnCountry:

Many factors. Back than they had not the information/media emergency bulletins and buildings might have been not that good.

yeah, thats true. might have been the same number of tornadoes, but not as many would have been reported

Quoting atmoaggie:

A rough day, certainly, but not quite in the level of the 1973 outbreak:

That map just blows my mind.... couldn't imagine being under siege like that...

Quoting drg0dOwnCountry:

Many factors. Back than they had not the information/media emergency bulletins and buildings might have been not that good.

Yup exactly right-- more eyes to witness, and more technology to detect nowadays

Quoting Levi32:


That's why I said "if" it's accurate. That year obviously could have rivaled 2005.

Yes I'm not that great at history, having only been around since the 90s lol. Writing my outlook for last year and this year was some of the only quality time I have really spent researching past hurricane seasons.

Levi, until 2005, that WAS the record year for numbers, etc. A lot of pple back in 05 were debating whether '33 was not actually worse than 2005, given the "blank 1/3 of the map" atmo drew our attention to in an earlier post.

The years between 1925 and 1935 were some of the worst for Bahamian hurricane history - I think we had more majors through here in those 10 years than we did in the next 40 or 50.....

Sure hope we aren't going to have another year like 1926, 1928, or 1933.....

Plus Doppler radar wasnt as powerful back then. So radar had a hard time depicting rotation like it does now, not all tornado's show a hook echo on radar, some are hidden in clouds and heavy rain shields.

Probably the only way they got those estimates was from actually walking the storm paths.

Good afternoon all

It looks like we will get a nice downpour here in the Caymans real soon. We do need it. Only .20 of an inch for feb and not much more than that since last year. The dry season is in full swing here now.

GOM AVN Flash loop

Quoting MississippiWx:


I saw that too. Really strange since the 6z run was really the first time it cranked up that low in the Central GOM, causing it to suck down plenty of cold air and causing another snowstorm way far south into the Gulf Coast region. Going to be interesting to see if the 6z run was picking up on something and the 12z run was just a bad run. Have any idea what the 12z European had?

Here it is...12Z ECMWF.

Maybe the 12Z GFS was a bad run.

Quoting tornadodude:


yeah, thats true. might have been the same number of tornadoes, but not as many would have been reported

That is why we have scientist who research this ;)
And they say today that storms get more intense and bigger.

Tropical storms to be more intense but less frequent: climate study

I think they will be more frequent.
Hurricanes Now Stronger and More Frequent Than Anytime in Past 1,000 Years
At least, according to one study.

If you see storms, the are increasing, for example this 2 winter blizzards in the US statisticly only happen once in 700 years. We will find out ;)

Hey, Kman. We're having one of our rainier Febs so far, Though I don't think the numbers for the winter are up overall....

Quoting kmanislander:
Good afternoon all

It looks like we will get a nice downpour here in the Caymans real soon. We do need it. Only .20 of an inch for feb and not much more than that since last year. The dry season is in full swing here now.

GOM AVN Flash loop

Impressive Convection with this storm system...

Quoting IKE:
This website is having issues loading today or is simply down for service. Take your pick.

Looks like the 12Z GFS backed w-a-y off on next weeks GOM storm. Good news.

Excerpt from EXTENDED FORECAST DISCUSSION


OVERALL...12 UTC GUIDANCE CONTINUED TO SUPPORT A
SIMILAR LARGER SCALE PATTERN DEVELOPMENT FOR MUCH OF THE
PERIOD...BUT FORECAST SPREAD DID INCREASE SUBSTANTIALLY BY DAYS
6/7 WITH SYSTEM DEEPENING/TRACK OUT FROM THE SRN/SERN US/GULF OF
MEX TO THE WRN ATLANTIC. THE 12 UTC GFS/UKMET SEEM OUTLIERS WITH A
FAR SOUTHWARD SUPPRESSED OFFSHORE TRACK NOT SUPPORTED BY
CONTINUITY...12 UTC GFS ENSEMBLES...12 UTC CANADIAN...OR
ESPECIALLY THE 12 UTC ECMWF THAT STILL SUPPORTS DEEP COASTAL STORM
POTENTIAL.

Quoting BahaHurican:
Hey, Kman. We're having one of our rainier Febs so far, Though I don't think the numbers for the winter are up overall....

Send some this way :-)

Dry as a bone here and my cistern is three quarters empty. I sure don't want to start watering the yard with mains water !!

Quoting drg0dOwnCountry:
Cyclones striking Gulf Coast in recent years have generated more twisters that those that hit the region in the mid-20th century

Hurricanes and tropical storms striking the Gulf Coast region since 1995 have spun off more twisters than those that hit during the mid-20th century, mostly because the more-recent storms have been broader and therefore have covered more area, a new study suggests.

They're crazy. In locations that get the eyewall winds, there are 2 ways to figure if a tornado happened. Eye witness and radar signature. Debris patterns are tough to use where the hurricane winds were very strong.

So, given that we know well that population density had a lot to do with reported visible confirmations of tornadoes and tornado damage, I think we could discount that as a viable means to determine tornadoes in the mid-20th century and now.

Wiki: "In 1953, Donald Staggs, an electrical engineer working for the Illinois State Water Survey, made the first recorded radar observation of a "hook echo" associated with a tornadic thunderstorm.[3]

Between 1950 and 1980, reflectivity radars, which measure position and intensity of precipitation, were built by weather services around the world. The early meteorologists had to watch a cathode ray tube. During the 1970s, radars began to be standardized and organized into networks. The first devices to capture radar images were developed. The number of scanned angles was increased to get a three-dimensional view of the precipitation, so that horizontal cross-sections (CAPPI) and vertical ones could be performed. Studies of the organization of thunderstorms were then possible for the Alberta Hail Project in Canada and National Severe Storms Laboratory (NSSL) in the US in particular.

The NSSL, created in 1964, began experimentation on dual polarization signals and on Doppler effect uses. In May 1973, a tornado devastated Union City, Oklahoma, just west of Oklahoma City. For the first time, a Dopplerized 10-cm wavelength radar from NSSL documented the entire life cycle of the tornado.[4] The researchers discovered a mesoscale rotation in the cloud aloft before the tornado touched the ground : the tornadic vortex signature. NSSL’s research helped convince the National Weather Service that Doppler radar was a crucial forecasting tool.[4] The Super Outbreak of tornadoes on April 3–4, 1974 and their devastating destruction might have helped to get funding for further developments."

(nice how everything went in a circle, here)
Radar clearly didn't have the capability that it does now to detect rotation. Before the WSR-88D, we had little profile information and, usually, no radial velocity data. And without the algorithms that look for rotation in the data, we would be dependent on a human observer with eyelids stapled back over a CRT. Forget it.

So, just how could they figure on tornadoes in hurricanes before good coverage from WSR-88D radars? They modeled it. We cannot successfully produce a computer-modeled tornado using the physics we have today without inducing one, but we are supposed to believe they can accurately figure tornadoes in hurricanes?

Sorry. That sounds loco.

And to say that we know that hurricanes lately have become larger is absurd, too. I don't believe anyone can say they are confident in hurricane RMW or TS-force extents for hurricanes before the 70s, considering the difference in measurement systems through the years. (see Landsea paper)

118 Stormchaser

It almost looks as if a surface low is trying to form on the SW side of that blow up. Very unusual to see convection that heavy in the NW Caribbean this time of year. Typically we get rain ahead of a front but in a passing shower.

Quoting IKE:


Here it is...12Z ECMWF.

Maybe the 12Z GFS was a bad run.

Oh wow...ECMWF has it pretty strong in the Central Gulf. I knew it had been advertising this for a few days now. If that plays out, it could be a monster storm. I must admit, I won't mind seeing one more snow here before winter winds down. We've had three snows here in Hattiesburg this year (third one happened this morning...heavy snow off and on for about an hour and a half). Today's didn't accumulate but it was still beautiful.

Quoting nrtiwlnvragn:


Excerpt from EXTENDED FORECAST DISCUSSION


OVERALL...12 UTC GUIDANCE CONTINUED TO SUPPORT A
SIMILAR LARGER SCALE PATTERN DEVELOPMENT FOR MUCH OF THE
PERIOD...BUT FORECAST SPREAD DID INCREASE SUBSTANTIALLY BY DAYS
6/7 WITH SYSTEM DEEPENING/TRACK OUT FROM THE SRN/SERN US/GULF OF
MEX TO THE WRN ATLANTIC. THE 12 UTC GFS/UKMET SEEM OUTLIERS WITH A
FAR SOUTHWARD SUPPRESSED OFFSHORE TRACK NOT SUPPORTED BY
CONTINUITY...12 UTC GFS ENSEMBLES...12 UTC CANADIAN...OR
ESPECIALLY THE 12 UTC ECMWF THAT STILL SUPPORTS DEEP COASTAL STORM
POTENTIAL.

Thanks. Looks like they threw the 12Z GFS out.

Q4 down around Boca is showing signs of rotation. Could be a brief tornado with that cell.

Quoting kmanislander:
118 Stormchaser

It almost looks as if a surface low is trying to form on the SW side of that blow up. Very unusual to see convection that heavy in the NW Caribbean this time of year. Typically we get rain ahead of a front but in a passing shower.

Interactive Goes

I'd say your are correct you can see the northwest side trying to wrap around and it is building some serious convection on the northeastern side.

Quoting atmoaggie:

They're crazy.
Sorry. That sounds loco.

And to say that we know that hurricanes lately have become larger is absurd, too.

You use NOAA as your source. NOAA said 2008
NOAA Says Hurricanes Becoming Less Frequent, More Intense
http://www.contingencyplanning.com/articles/63340/

Now in 2010 scientist come to a consensus that storms weill be more intense.

What about your grafic atmo, please cite the source. Currently it is from tinypic ...

Quoting IKE:


Thanks. Looks like they threw the 12Z GFS out.

Appears to be a low confidence forecast... the GFS may end up being correct, too early to know. HPC is a lot like NHC in they will usually not make large changes in their forecasts, but gradually. The continuity thing...

Quoting tornadodude:


yeah, thats true. might have been the same number of tornadoes, but not as many would have been reported

1971-94 was the last lull period too...

Quoting tornadodude:
103:

Couldnt that be because of higher population along the coastal areas?

i think 3 of the 7 people killed were in panama city area and only one was on the coast. two were in a little rural isolated town on east bay called allenton. one guy hid in the closet with the hot water heater and when the tornado hit he was scalded to death. an elderly woman was killed when the tornado picked up her block house and set it back down on her in a rain of broken concrete. a box of momentos from her attic was found fifty miles away on the roof of a house in gulf county.

Quoting nrtiwlnvragn:


Appears to be a low confidence forecast... the GFS may end up being correct, too early to know. HPC is a lot like NHC in they will usually not make large changes in their forecasts, but gradually. The continuity thing...

See what the next GFS run shows.

Tracks for all storms reaching category 4 or 5 intensity, for the control and the warmed 18-model ensemble conditions, as obtained using the GFDL/NWS hurricane model.

*Intriguingly, while normal El Niños tend to suppress Atlantic hurricanes, so-called Modoki El Niños are actually positively correlated with them, and as the planet warms it looks as though Modoki El Niños are becoming more common.

Relevant sections from the AR4 are below the fold:

From the IPCC AR4 WG1 section on tropical cyclones (“Box 3.5: Tropical Cyclones and Changes in Climate”):

In the summer tropics, outgoing longwave radiative cooling from the surface to space is not effective in the high water vapour, optically thick environment of the tropical oceans. Links to higher latitudes are weakest in the summer tropics, and transports of energy by the atmosphere, such as occur in winter, are also not an effective cooling mechanism, while monsoonal circulations between land and ocean redistribute energy in areas where they are active. However, tropical storms cool the ocean surface through mixing with cooler deeper ocean layers and through evaporation. When the latent heat is realised in precipitation in the storms, the energy is transported high into the troposphere where it can radiate to space, with the system acting somewhat like a Carnot cycle (Emanuel, 2003). Hence, tropical cyclones appear to play a key role in alleviating the heat from the summer Sun over the oceans.

As the climate changes and SSTs continue to increase (see Section 3.2.2.3), the environment in which tropical storms form is changed. Higher SSTs are generally accompanied by increased water vapour in the lower troposphere (see Section 3.4.2.1 and Figure 3.20), thus the moist static energy that fuels convection and thunderstorms is also increased. Hurricanes and typhoons currently form from pre-existing disturbances only where SSTs exceed about 26°C and, as SSTs have increased, it thereby potentially expands the areas over which such storms can form. However, many other environmental factors also influence the generation and tracks of disturbances, and wind shear in the atmosphere greatly influences whether or not these disturbances can develop into tropical storms. The El Niño-Southern Oscillation and variations in monsoons as well as other factors also affect where storms form and track (e.g., Gray, 1984). Whether the large-scale thermodynamic environment and atmospheric static stability (often measured by Convective Available Potential Energy, CAPE) becomes more favourable for tropical storms depends on how changes in atmospheric circulation, especially subsidence, affect the static stability of the atmosphere, and how the wind shear changes. The potential intensity, defined as the maximum wind speed achievable in a given thermodynamic environment (e.g., Emanuel, 2003), similarly depends critically on SSTs and atmospheric structure. The tropospheric lapse rate is maintained mostly by convective transports of heat upwards, in thunderstorms and thunderstorm complexes, including mesoscale disturbances, various waves and tropical storms, while radiative processes serve to cool the troposphere. Increases in greenhouse gases decrease radiative cooling aloft, thus potentially stabilising the atmosphere. In models, the parametrization of sub-grid scale convection plays a critical role in determining whether this stabilisation is realised and whether CAPE is released or not. All of these factors, in addition to SSTs, determine whether convective complexes become organised as rotating storms and form a vortex.

While attention has often been focussed simply on the frequency or number of storms, the intensity, size and duration likely matter more. NOAA’s Accumulated Cyclone Energy (ACE) index (Levinson and Waple, 2004) approximates the collective intensity and duration of tropical storms and hurricanes during a given season and is proportional to maximum surface sustained winds squared. The power dissipation of a storm is proportional to the wind speed cubed (Emanuel, 2005a), as the main dissipation is from surface friction and wind stress eff ects, and is measured by a Power Dissipation Index (PDI). Consequently, the effects of these storms are highly nonlinear and one big storm may have much greater impacts on the environment and climate system than several smaller storms.

From an observational perspective then, key issues are the tropical storm formation regions, the frequency, intensity, duration and tracks of tropical storms, and associated precipitation. For landfalling storms, the damage from winds and flooding, as well as storm surges, are especially of concern, but often depend more on human factors, including whether people place themselves in harm’s way, their vulnerability and their resilience through such things as building codes.

From the AR4 WG2 section on tropical cyclones:

Variations in tropical and extra-tropical cyclones, hurricanes and typhoons in many small-island regions are dominated by ENSO and decadal variability which result in a redistribution of tropical storms and their tracks, so that increases in one basin are often compensated by decreases in other basins. For example, during an El Niño event, the incidence of tropical storms typically decreases in theAtlantic and far-western Pacific and the Australian regions, but increases in the central and eastern Pacific, and vice versa. Clear evidence exists that the number of storms reaching categories 4 and 5 globally have increased since 1970, along with increases in the Power Dissipation Index (Emanuel, 2005) due to increases in their intensity and duration (Trenberth et al., 2007). The total number of cyclones and cyclone days decreased slightly in most basins. The largest increase was in the North Pacific, Indian and South- West Pacific oceans. The global view of tropical storm activity highlights the important role of ENSO in all basins. The most active year was 1997, when a very strong El Niño began, suggesting that the observed record sea surface temperatures (SSTs) played a key role (Trenberth et al., 2007). For extratropical cyclones, positive trends in storm frequency and intensity dominate during recent decades in most regional studies performed. Longer records for the North Atlantic suggest that the recent extreme period may be similar in level to that of the late 19th century (Trenberth et al., 2007).

In the tropical South Pacific, small islands to the east of the dateline are highly likely to receive a higher number of tropical storms during an El Niño event compared with a La Niña event and vice versa (Brazdil et al., 2002). Observed tropical cyclone activity in the South Pacific east of 160°E indicates an increase in level of activity, with the most active years associated with El Niño events, especially during the strong 1982/1983 and 1997/1998 events (Levinson, 2005).Webster et al. (2005) found more than a doubling in the number of category 4 and 5 storms in the South-West Pacific from the period 1975–1989 to the period 1990–2004. In the 2005/2006 season, La Niña influences shifted tropical storm activity away from the South Pacific region to the Australian region and, in March and April 2006, four category 5 typhoons occurred (Trenberth et al., 2007).

In the Caribbean, hurricane activity was greater from the 1930s to the 1960s, in comparison with the 1970s and 1980s and the first half of the 1990s. Beginning with 1995, all but two Atlantic hurricane seasons have been above normal (relative to the 1981-2000 baseline). The exceptions are the two El Niño years of 1997 and 2002. El Niño acts to reduce activity and La Niña acts to increase activity in the North Atlantic. The increase contrasts sharply with the generally below-normal seasons observed during the previous 25-year period, 1975 to 1994. These multi-decadal fluctuations in hurricane activity result almost entirely from differences in the number of hurricanes and major hurricanes forming from tropical storms first named in the tropical Atlantic and Caribbean Sea.

In the Indian Ocean, tropical storm activity (May to December) in the northern Indian Ocean has been near normal in recent years. For the southern Indian Ocean, the tropical cyclone season is normally active from December to April. A lack of historical record-keeping severely hinders trend analysis (Trenberth et al., 2007).
http://thingsbreak.wordpress.com/2010/01/22/tropical-cyclones-climate-and-consensus/
http://www.ipcc.ch/

Interesting times coming for the climate models. I wonder how they will change without the homogenization or extrapolation that is in place today? Interesting that they would even consider it......

February 24, 2010
Met Office: we must check 150 years of climate data

Met office proposal

"The proposed activity would provide a set of independent assessments of surface temperature produced by independent groups using independent methods."

Quoting drg0dOwnCountry:

You use NOAA as your source. NOAA said 2008
NOAA Says Hurricanes Becoming Less Frequent, More Intense
http://www.contingencyplanning.com/articles/63340/

Now in 2010 scientist come to a consensus that storms weill be more intense.

What about your grafic atmo, please cite the source. Currently it is from tinypic ...

I am very familiar with that GFDL/NOAA study, thanks.
Here is my post about it in the climate change blog (hint,hint)

Quoting atmoaggie:
While the dog has fleas, considering they use the IPCC AR4 GCM projections (hey, what else could they do?), this is interesting, nonetheless.

Responses to general questions concerning that latest hurricane intensity/AGW report: http://www.gfdl.noaa.gov/21st-century-projections-of-intense-hurricanes/

Plot:

Try not to get too terribly excited about a hurricane intensity study completely dependent on climate model projections. (GIGO) But try out the link in my quote, far better than any other I have seen on the matter.

? My graphic is from the link posted with it. It was published in the EOS newsletter of the American Geophysical Union by Chris Landsea of NOAA's Atmospheric Oceanographic and Meteorological Laboratory (AOML).

Is any of that a problem for you?

Quoting drg0dOwnCountry:
From the IPCC AR4 WG1 section on tropical cyclones (%u201CBox 3.5: Tropical Cyclones and Changes in Climate%u201D)

Make sure you buy some sand on your next visit to a desert.

St. Petersburg, FL

57*F

Humidity: 81 %
Wind Speed: NW 24 G 30 MPH
Barometer: 29.77" (1008.0 mb)
Dewpoint: 51 °F (11 °C)
Visibility: 10.00 mi.

hi guys we going to get some rain and hope we get lots more I wish that the cold front dies and that surface trough turns in to a tropical wave and come over us and give more and more rain and some nice warm winds and way talk later around 5 or 6

Quoting BahaHurican:
Levi, until 2005, that WAS the record year for numbers, etc. A lot of pple back in 05 were debating whether '33 was not actually worse than 2005, given the "blank 1/3 of the map" atmo drew our attention to in an earlier post.

The years between 1925 and 1935 were some of the worst for Bahamian hurricane history - I think we had more majors through here in those 10 years than we did in the next 40 or 50.....

Sure hope we aren't going to have another year like 1926, 1928, or 1933.....

Yes I remember now discussing 1933 back in '05....like I said I was never very educated in hurricane history. I've only been tracking them for 5 years, so I'm still learning about some of the big years and historic storms back in the old days. It's hard to keep all the dates in my head the first time I look them up lol.

atmoaggie, Try not to get too terribly excited about a hurricane intensity study completely dependent on climate model projections.


Maybe you talk about something else, this study i refering to looked at peer-reviewed studys from past 4 years.

Tropical storms to be more intense
Known in the Atlantic as hurricanes and in eastern Asia as typhoons, tropical storms are driven by the raw fuel of warm seas, which raises the question about what may happen when temperatures rise as a result of greenhouse gases.

Tom Knutson and colleagues from the UN's World Meteorological Organisation (WMO) looked at peer-reviewed investigations that have appeared over the past four years, when the issue began to hit the headlines.

Their benchmark for warming is the "A1B" scenario, a middle-of-the-road computer simulation which predicts a global average surface temperature rise of 2.8 degrees Celsius (5.4 degrees Fahrenheit) over the 21st century.

"It is likely that the global frequency of tropical cyclones will either decrease or remain essentially unchanged," says the paper.

But storms could have more powerful winds -- an increase of between two and 11 percent -- and dump more water, it warns.

Rainfall could increase by 20 percent within 100 kilometres (62 miles) of the eye of the storm.

In addition, some storm basins will "more likely than not" see a big increase in the frequency of high-impact storms.
However, the panel said it was less confident in concluding whether the number of cyclones would decrease.

http://www.google.com/hostednews/afp/article/ALeqM5gwvgbRc4epCac4RjL99yTubj6mGA

Is the intensity of hurricanes increasing?

Several peer-reviewed studies show a clear global trend toward increased intensity of the strongest hurricanes over the past two or three decades. The strongest trends are in the North Atlantic Ocean and the Indian Ocean. According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), it is “more likely than not” (better than even odds) that there is a human contribution to the observed trend of hurricane intensification since the 1970s. In the future, “it is likely [better than 2 to 1 odds] that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical [sea surface temperatures].”
http://www.pewclimate.org/hurricanes.cfm#change

drgodOwnCountry... Neat post. As the the globe warms ( regardless if man has contributed to it or not ) I believe We will see a gradual change in the common weather patterns that we are familiar with. The idea that we may see less tropical cyclones but more intense ones is an interesting thought. I have always wondered if the weather patterns were just right over the Atlantic, how many major hurricanes could form in one season?

Quoting hydrus:
how many major hurricanes could form in one season?

The size, intensity and duration of even a single hurricane could be enough.

Quoting drg0dOwnCountry:

The size, intensity and duration of even a single hurricane could be enough.

I know that! :) What I am trying to say is that in the past there may have been weather patterns that were more proficient for spawning numerous intense hurricanes.

Afternoon,all,hope everyone is doing ok,up here in new england we have a tale of two storms in one.The western portion of new england getting dumped with 1to2 feet of snow,with power outages all over the place.Im in eastern Mass and getting almost 2 inches of rain.Brief lull tonight and anothe round of 2 inch rains tomorrow.

Quoting drg0dOwnCountry: 132. drg0dOwnCountry 7:54 PM GMT on February 24, 2010

Some things to point out...

"*Intriguingly, while normal El Ninos tend to suppress Atlantic hurricanes, so-called Modoki El Ninos are actually positively correlated with them, and as the planet warms it looks as though Modoki El Ninos are becoming more common."

Modoki El Ninos are centered more westward over the central equatorial Pacific, and El Ninos will tend to behave this way when they form within a cold PDO. We have been beginning to head back down into a cold PDO for the last 10 years, and if you notice El Ninos have indeed become biased more often towards the central Pacific as opposed to the eastern Pacific.

"Clear evidence exists that the number of storms reaching categories 4 and 5 globally have increased since 1970"

Because the PDO was cold until 1978, after which it has been in its warm phase until the late 2000s. A cold PDO kept the world's oceans generally cold from the 1940s through the 1970s, but after going into its warm phase the world oceans warmed, increasing the number of intense hurricanes.

"Longer records for the North Atlantic suggest that the recent extreme period may be similar in level to that of the late 19th century "

The late 19th century would have been during the last intersection of a cold PDO and warm AMO, which is very conducive to active North Atlantic hurricane seasons.

"In the Caribbean, hurricane activity was greater from the 1930s to the 1960s, in comparison with the 1970s and 1980s and the first half of the 1990s.Beginning with 1995, all but two Atlantic hurricane seasons have been above normal (relative to the 1981-2000 baseline)."

Guess why? If you look at the AMO graph, the Atlantic was clearly warm from the 1930s to the 1960s. The AMO went cold from the mid-60s through the early 90s, and also combined with a warm PDO from the late 70s onward, hence the slack in activity compared to the previous 30 years. In 1995 guess what happened, the AMO went warm, increasing Atlantic (Caribbean) hurricane activity once again.

"The increase contrasts sharply with the generally below-normal seasons observed during the previous 25-year period, 1975 to 1994."

And once again we find that from 1975 to 1994 the AMO was cold and the PDO was warm, resulting in a colder-than-normal Atlantic Ocean and unfavorable conditions aloft, resulting in lowered hurricane activity. It's no surprise that after the AMO went warm in 1995 and the PDO is now going cold, hurricane activity will sharply increase over the North Atlantic basin.
~~~~~~~~~~~

So....Global Warming caused all this? I think not. Look at the PDO and AMO graphs and compare to all the quotes and dates I just listed from that paper. Look up the data yourself and see what was going on during the periods of low and high tropical cyclone activity world-wide. You'll be amazed at how much sense it makes.

Quoting Levi32:


Some things to point out...

We talk on 2 diffrent subjects here. First the IPCC report from 2007 and the new study looking at last 4 years of studys.

You just responded to the 2007 IPCC report on climate change and tropical storms.
I read your comments.

FYI...

It appears that a killer whale lived up to its name...

In front of a crowd, too... yikes

Quoting drg0dOwnCountry:

We talk on 2 diffrent subjects here. First the IPCC report from 2007 and the new study looking at last 4 years of studys.

You just responded to the 2007 IPCC report on climate change and tropical storms.
I read your comments.

I don't care what papers they are or if it's 2 papers or 1 it doesn't matter. What matters is people saying this:

"*Intriguingly, while normal El Niños tend to suppress Atlantic hurricanes, so-called Modoki El Niños are actually positively correlated with them, and as the planet warms it looks as though Modoki El Niños are becoming more common."

...Obviously referring to Global Warming, as I know you are a supporter of GW. I'm trying to point out why GW shouldn't be the automatically assumed cause of the result of these papers.

Trainer killed by killer whale at SeaWorld in Fla. Link

Quoting Levi32:


I don't care what papers they are or if it's 2 papers or 1 it doesn't matter. What matters is people saying this:

"*Intriguingly, while normal El Niños tend to suppress Atlantic hurricanes, so-called Modoki El Niños are actually positively correlated with them, and as the planet warms it looks as though Modoki El Niños are becoming more common."

...Obviously referring to Global Warming, as I know you are a supporter of GW. I'm trying to point out why GW shouldn't be the automatically assumed cause of the result of these papers.

I think this was not the point here. The point is that we can observe storms which last longer, drop more precipitation, cost more money etc. And this is from warmer waters/temperatures.
We need clean energy to prevent more warming.