Dr. Jeff Masters' WunderBlog

Volcanic Winter

Posted by: Dr. Jeff Masters, 01:18 PM GMT del 24 Aprile 2009

"The sun was dark and its darkness lasted for eighteen months; each day it shone for about four hours; and still this light was only a feeble shadow; the fruits did not ripen and the wine tasted like sour grapes." As this Michael the Syrian quote regarding the weather of 536 A.D. demonstrates, a climate catastrophe that blots out the sun can really spoil your day. Procopius of Caesarea remarked: "During this year [536 A.D.] a most dread portent took place. For the sun gave forth its light without brightness. and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear." Many documents from 535 - 536 A.D.--the time of King Arthur in Britain--speak of the terrible "dry fog" or cloud of dust that obscured the sun, causing widespread crop failures in Europe, and summer frosts, drought, and famine in China. Tree ring studies in Europe confirm several years of very poor growth around that time, and ice cores from Greenland and Antarctica show highly elevated levels of atmospheric sulfuric acid dust existed.

Though some scientists believe the climate calamity of 535-536 A.D. was due to a comet or asteroid hitting the Earth, it is widely thought that the event was probably caused by the most massive volcanic eruption of the past 1500 years. This eruption threw so much sulfur dioxide (SO2) gas into the stratosphere that a "Volcanic Winter" resulted. Sulfur dioxide reacts with water to form sulfuric acid droplets (aerosol particles), which are highly reflective and reduce the amount of incoming sunlight. The potential eruption that led to the 535 - 536 A.D. climate calamity would have likely been a magnitude 7 event on the Volcanic Explosivity Index (VEI)--a "super colossal" eruption that one can expect to occur only once every 1000 years. The Volcanic Explosivity Index is a logarithmic scale like the Richter scale used to rate earthquakes, so a magnitude 7 eruption would eject ten times more material than the two largest eruptions of the past century--the magnitude 6 eruptions of Mt. Pinatubo in the Philippines (1991) and Novarupta in Alaska (1912).

Figure 1. An 18 km-high volcanic plume from one of a series of explosive eruptions of Mount Pinatubo beginning on 12 June 1991, viewed from Clark Air Base (about 20 km east of the volcano). Three days later, the most powerful eruption produced a plume that rose nearly 40 km, penetrating well into the stratosphere. Pinatubo's sulfur emissions cooled the Earth by about 1°F (0.5°C) for 1 - 2 years. (Photograph by David H. Harlow, USGS.)

Super-colossal eruptions
There has been only one other magnitude 7 "super-colossal" eruption in the past 1500 years--the massive eruption of the Indonesian volcano Tambora in 1815. The sulfur pumped by this eruption into the stratosphere dimmed sunlight so extensively that global temperatures fell by about 2°F (1°C) for 1 - 2 years afterward. This triggered the famed Year Without a Summer in 1816. Killing frosts and snow storms in May and June 1816 in Eastern Canada and New England caused widespread crop failures, and lake and river ice were observed as far south as Pennsylvania in July and August. The Tambora eruption was about 40% smaller than the 535 - 536 A.D. event, as measured by the number of sulfur aerosol particles deposited in Greenland ice cores.

In an article published in 2008 in the American Geophysical Union journal EOS, Dr. Ken Verosub of the University of California, Davis Department of Geology estimated that future eruptions capable of causing "Volcanic Winter" effects severe enough to depress global temperatures by 2°F (1°C) and trigger widespread crop failures for 1 - 2 years afterwards should occur about once every 200 - 300 years. Even a magnitude 6 eruption, such as the 1600 eruption of the Peruvian volcano Huaynaputina, can cause climatic change capable of killing millions of people. The Huaynaputina eruption is blamed for the Russian famine of 1601-1603, which killed over half a million people and led to the overthrow of Tsar Boris Godunov. Thankfully, the climatic impacts of all of these historic magnitude 6 and 7 eruptions have been relatively short-lived. After about two years, the sulfuric acid aerosol particles have settled out of the stratosphere, returning the climate to its former state.

Mega-colossal eruptions
Even more extreme eruptions have occurred in Earth's past--eruptions ten times more powerful than the Tambora eruption, earning a ranking of 8 out of 8 on the Volcanic Explosivity Index (VEI). These "mega-colossal" eruptions occur only about once every 10,000 years, but have much longer-lasting climatic effects and thus are a more significant threat to human civilization. According to the Toba Catastrophe Theory, a mega-colossal eruption at Toba Caldera, Sumatra, about 74,000 years ago, was 3500 times greater than the Tambora eruption. According to model simulations, an eruption this large can pump so much sulfur dioxide gas into the stratosphere that the atmosphere does not have the capacity to oxidize all the SO2 to sulfuric acid aerosol. The atmosphere oxidizes as much SO2 as it can, leaving a huge reservoir of SO2 in the stratosphere. This SO2 gradually reacts to form sulfuric acid as the OH radicals needed for this reaction are gradually produced. The result is a much longer-lasting climate effect than the 1 - 2 years that the magnitude 6 and 7 events of 535, 1600, 1815, and 1991 lasted. A magnitude 8 eruption like the Toba event can cool the globe for 6 - 10 years (Figure 3), which may be long enough to trigger an ice age--if the climate is already on the verge of tipping into an ice age. Rampino and Self (1992) argued that the sulfur aerosol veil from Toba was thick and long-lasting enough to cool the globe by 3 - 5°C (5 - 9°F), pushing the climate--which was already cooling and perhaps headed towards an ice age--into a full-scale ice age. They suggested that the response of Canada to the volcano played a particularly important role, with their model predicting a 12°C (22°F) reduction in summer temperatures in Canada. This would have favored the growth of the Laurentide ice sheet, increasing the reflectivity (albedo) of the Earth, reflecting more sunlight and reducing temperatures further. The controversial Toba Catastrophe Theory asserts that the resulting sudden climate change reduced the Earth's population of humans to 1,000 - 10,000 breeding pairs. More recent research has shed considerable doubt on the idea that the Toba eruption pushed the climate into an ice age, though. Oppenheimer (2002) found evidence supporting only a 2°F (1.1°C) cooling of the globe, for the 1000 years after the Toba eruption. Zielinski et al. (1996) argued that the Toba eruption did not trigger a major ice age--the eruption merely pushed the globe into a cool period that lasted 200 years. Interestingly, a previous super-eruption of Toba, 788,000 years ago, coincided with a transition from an ice age to a warm period.

Figure 2. The 100x30 square kilometer Toba Caldera is situated in north-central Sumatra around 200 km north of the Equator. It is comprised of four overlapping calderas aligned with the Sumatran volcanic chain. Repeated volcanic cataclysms culminated in the stupendous expulsion of the Younger Toba Tuff around 74,000 years ago. The lake area is 100 square kilometers. Samosir Island formed as a result of subsequent uplift above the evacuated magma reservoir. Such resurgent domes are typically seen as the concluding phase of a large eruption. Landsat Enhanced Thematic Mapper Plus (ETM+) browse images for path/row 128/58 (6 September 1999) and 129/58 (21 January 2001) from http://landsat7.usgs.gov/. Copyright USGS. Image source: Oppenheimer, C., 2002, "Limited global change due to the largest known Quaternary eruption, Toba 74 kyr BP?"Quaternary Science Reviews, 21, Issues 14-15, August 2002, Pages 1593-1609.

Figure 3. Total mass of sulfur dioxide and sulfate aerosol in the stratosphere (heavy solid and dotted lines, respectively) modeled for a 6 petagram stratospheric injection of SO2. Observed SO2 and aerosol mass for the 1991 Pinatubo eruption are shown for comparison. The much larger amount of SO2 in the Toba simulation soaks up all available oxidants in the stratosphere leading to a much longer lifetime of SO2 and, in turn, prolonging the manufacture of sulfate aerosol. Data from Read et al. (1993) and Bekki et al. (1996). Image source: Oppenheimer, C., 2002, "Limited global change due to the largest known Quaternary eruption, Toba 74 kyr BP?"Quaternary Science Reviews, 21, Issues 14-15, August 2002, Pages 1593-1609.

When can we expect the next mega-colossal eruption?
Given the observed frequency of one mega-colossal magnitude 8 volcanic eruption every 1.4 million years, the odds of another hitting in the next 100 years is about .014%, according to Mason et al., 2004. This works out to a 1% chance over the next 7200 years. Rampino (2002) puts the average frequency of such eruptions at once every 50,000 years--about double the frequency with which 1-km diameter comets or asteroids capable of causing a similar climatic effect hit the Earth. A likely location for the next mega-colossal eruption would be at the Yellowstone Caldera in Wyoming, which has had magnitude 7 or 8 eruptions as often as every 650,000 years. The last mega-colossal eruption there was about 640,000 years ago. But don't worry, the seismic activity under Yellowstone Lake earlier this year has died down, and the uplift of the ground over the Yellowstone caldera that was as large as 7 cm/yr (2.7 inches/yr) between 2004 - 2006 has now fallen to 4 cm/yr, according to the Yellowstone Volcano Observatory. The USGS states that "the Yellowstone volcanic system shows no signs that it is headed toward such an eruption. The probability of a large caldera-forming eruption within the next few thousand years is exceedingly low".

What would happen if a magnitude 8 mega-colossal eruption were to occur today?
If a mega-colossal eruption were to occur today, it would probably not be able to push Earth into an ice age, according to a modeling study done by Jones et al. (2005). They found that an eruption like Toba would cool the Earth by about 17°F (9.4°C) after the first year (Figure 3), and the temperature would gradually recover to 3°F (1.8°C) below normal ten years after the eruption. They found that the eruption would reduce rainfall by 50% globally for the first two years, and up to 90% over the Amazon, Southeast Asia, and central Africa. This would obviously be very bad for human civilization, with the cold and lack of sunshine causing widespread crop failures and starvation of millions of people. Furthermore, the eruption would lead to a partial loss of Earth's protective ozone layer, allowing highly damaging levels of ultraviolet light to penetrate to the surface.

Not even a mega-colossal eruption of this magnitude would stop global warming, though. The level of greenhouse gases in the atmosphere would not be affected by the volcanic eruption, and warming would resume where it left off once the stratospheric dust settled out in a decade. With civilization crippled by the disaster, greenhouse gas emissions would be substantially reduced, though (small solace!) If we really want to say goodbye to civilization, a repeat of the only magnitude 9 eruption in recorded history should do the trick--the magnitude 9.2 La Garita, Colorado blast of 27.8 million years ago (Mason et al., 2004).

Figure 4. Annual near-surface temperature anomalies for the year following a mega-colossal volcanic eruption like the Toba eruption of 74,000 years ago, if it were to occur today. Most land areas cool by 22°F (12°C) compared to average. Some areas, like Africa, cool by 29°F (16°C). Image credit: Jones, G.S., et al., 2005, "An AOGCM simulation of the climate response to a volcanic super-eruption", Climate Dynamics, 25, Numbers 7-8, pp 725-738, December, 2005.

What would happen if a magnitude 7 super-colossal eruption were to occur today?
An eruption today like the magnitude 7 events of 535 A.D. or 1815 would cause cause wide-spread crop failures for 1 - 2 years after the eruption. With food supplies in the world already stretched thin by rising population, decreased water availability, and conversion of cropland to grow biofuels, a major volcanic eruption would probably create widespread famine, threatening the lives of millions of people. Wars over scarce resources might result. However, society's vulnerability to major volcanic eruptions is less than it was, since the globe has warmed significantly in the past 200 years. The famines from the eruptions of 1600 and 1815 both occurred during the Little Ice Age, when global temperatures were about 1.4°F (0.8°C) cooler than today. Crop failures would not be as wide-spread with today's global temperatures, if a suer-colossal eruption were to occur. Fifty years from now, when global temperatures are expected to be at least 1°C warmer, a magnitude 7 eruption should only be able to cool the climate down to year 2009 levels.

Volcanoes also warm the climate
While volcanoes cool the climate on time scales of 1 - 2 years, they act to warm the climate over longer time scales, since they are an important source of natural CO2 to the atmosphere. Volcanoes add 0.1 - 0.3 gigatons (Gt) of carbon to the atmosphere each year, which is about 1 - 3% of what human carbon emissions to the atmosphere were in 2007, according to the Global Carbon Project. In fact, volcanoes are largely responsible for the natural CO2 in the atmosphere, and helped make life possible on Earth. Why, then, haven't CO2 levels continuously risen over geologic time, turning Earth into a steamy hothouse? In fact, CO2 levels have fallen considerably since the time of the dinosaurs--how can this be? Well, volcano-emitted CO2 is removed from the atmosphere by chemical weathering. This occurs when rain and snow fall on rocks containing silicates. The moisture and silicates react with CO2, pulling it out of the air. The carbon removed from the air is then washed into the sea, where it ends up in ocean sediments that gradually harden into rock. Rates of chemical weathering on Earth have accelerated since the time of the dinosaurs, largely due to the recent uplift of the Himalaya Mountains and Tibetan Plateau. These highlands undergo a tremendous amount of weathering, thanks to their lofty heights and the rains of the Asian Monsoon that they capture. Unfortunately, chemical weathering cannot help us with our current high levels of greenhouse gases, since chemical weathering takes thousands of years to remove significant amounts of CO2 from the atmosphere. It takes about 100,000 years for silicate weathering to remove 63% of the CO2 in the atmosphere. Thus, climate models predict that chemical weathering will solve our greenhouse gas problem in about 100,000 - 200,000 years.

For further information
PBS TV special on the 535-536 A.D. disaster.
Newspaper articles on the 535-536 A.D. disaster.
Volcanic winter article from wikipedia.
Realclimate.org has a nice article that goes into the volcano-climate connection in greater detail.

References
Bekki, S., J.A. Pyle, W. Zhong, R. Toumi, J.D. Haigh and D.M. Pyle, 1996, "The role of microphysical and chemical processes in prolonging the climate forcing of the Toba eruption", Geophysical Research Letters 23 (1996), pp. 2669-2672.

Jones, G.S., et al., 2005, "An AOGCM simulation of the climate response to a volcanic super-eruption", Climate Dynamics, 25, Numbers 7-8, pp 725-738, December, 2005.

Rampino, M.R., and S. Self, 1993, "Climate-volcanism feedback and the Toba eruption of 74,000 years ago", Quaternary Research 40 (1993), pp. 269-280.

Mason, B.G., D.M. Pyle, and C. Oppenheimer, 2004, "The size and frequency of the largest observed explosive eruptions on Earth", Bulletin of Volcanology" 66, Number 8, December 2004, pp 735-748.

Oppenheimer, C., 2002, "Limited global change due to the largest known Quaternary eruption, Toba 74 kyr BP?"Quaternary Science Reviews, 21, Issues 14-15, August 2002, Pages 1593-1609.

Rampino, M.R., 2002, "Supereruptions as a Threat to Civilizations on Earth-like Planets", Icarus, 156, Issue 2, April 2002, Pages 562-569.

Read, W.G., L. Froidevaux and J.W. Waters, 1993, "Microwave Limb Sounder measurements of stratospheric SO2 from the Mt. Pinatubo eruption", Geophysical Research Letters 20 (1993), pp. 1299-1302.

Verosub, K.L., and J. Lippman, 2008, "Global Impacts of the 1600 Eruption of Peru's Huaynaputina Volcano", EOS 89, 15, 8 April 2008, pp 141-142.

Zielinski, G.A. et al., 1996, "Potential Atmospheric Impact of the Toba Mega-Eruption 71,000 Years Ago", Geophysical Research Letters, 23, 8, pp. 837-840, 1996.

Portlight moves to provide relief for South Carolina wildfires
South Carolina's biggest wildfire in more than three decades --a blaze four miles wide--destroyed dozens of homes near Myrtle Beach yesterday. Portlight Strategies, Inc. is preparing to respond to this disaster, focusing on providing drinks and sanitary products to firefighters, particularly to rural volunteer fire departments and other first responders which do not have the same resources as some of the larger paid departments. To help out, visit the Portlight South Carolina fire relief web page. Thanks!

Jeff Masters

Categories: Climate Change Volcano

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2201. KEEPEROFTHEGATE (Mod) 03:27 AM GMT del 29 Aprile 2009
so pat my good bud sir are you awaiting the 00z gfs run this evening Member Since: Luglio 15, 2006 Posts: 143 Comments: 40442

2202. hahaguy 03:28 AM GMT del 29 Aprile 2009
Quoting KEEPEROFTHEGATE: so pat my good bud sir are you awaiting the 00z gfs run this evening Oh god LMAO Member Since: Agosto 12, 2007 Posts: 2 Comments: 2838

2203. Patrap 03:28 AM GMT del 29 Aprile 2009
Chic' Masks fore the Fashion minded Flu crowd. Member Since: Luglio 3, 2005 Posts: 370 Comments: 111244

2204. KEEPEROFTHEGATE (Mod) 03:29 AM GMT del 29 Aprile 2009
Quoting Orcasystems: IF.... If they make it to my name... I have been invited to The Keys... Tampa and Destin... hmm I wonder where I will go :) i don't see orca or fish on the list Member Since: Luglio 15, 2006 Posts: 143 Comments: 40442

2205. Orcasystems 03:30 AM GMT del 29 Aprile 2009
Quoting KEEPEROFTHEGATE: i don't see orca or fish on the list Noooo, but Sam is :) Member Since: Ottobre 1, 2007 Posts: 77 Comments: 26077

2206. Patrap 03:31 AM GMT del 29 Aprile 2009
By time the GFS runs.. I'll be Gone Found Slumber easily. I never track Ghosts. Theres a-plenty of them in dem Machines Lad's. The real Ones are the Challenge. Not no Foo-Foo Storms from "Craig" Heads servers crunching alpha Bits. Member Since: Luglio 3, 2005 Posts: 370 Comments: 111244

2208. CatastrophicDL 03:35 AM GMT del 29 Aprile 2009
Quoting StSimonsIslandGAGuy: Link Thank you so much for sharing that. What an awesome experience that must have been. One of those once in a lifetime experiences. Fabulous and great pictures! Member Since: Settembre 3, 2007 Posts: 3 Comments: 1519

2211. KEEPEROFTHEGATE (Mod) 03:41 AM GMT del 29 Aprile 2009
that top one looks like a kangaroo face pat get your kangaroo mask here but really my property manger gave me a 100 dollar mask today in the event i have an outbreak in the building black with two purple filters on it top of the line air in thougt filters out though bottom works good he also deliver a protocol work sheet to follow and who to report to any suspicus cases of sickness i may come across also order 10 cases 20 cans of lysol diseficant and 10 bottles of dettoil they are really worried here but i think there makin more of it then is needed but its a job and like he said i am exposed to 2000 to 3000 people daily with everyone in the building its just like sars all over again Member Since: Luglio 15, 2006 Posts: 143 Comments: 40442

2213. Patrap 03:44 AM GMT del 29 Aprile 2009
What is SkinWear? Now you can protect yourself from germs at home, work or play, in school, while traveling, eating out or just about anywhere with SkinWear. Germs are everywhere and impossible not to pick up. Eighty percent of all infectious diseases are passed along by human contact, either direct or indirect, viruses like pneumonia, salmonella and the common cold. Beyond the people you and your family come in contact with, what can you do about all the door handles, faucets, desktops, telephones and more you touch everyday? This is where SkinWear comes in. Member Since: Luglio 3, 2005 Posts: 370 Comments: 111244

2215. moonlightcowboy 03:45 AM GMT del 29 Aprile 2009
Quoting Patrap: ...Not no Foo-Foo Storms from "Craig" Heads servers crunching alpha Bits. ...say it ain't so, Pat. We know this is gonna be a CAT 5 headed to NOLA - isn't it? ;) Member Since: Luglio 9, 2006 Posts: 179 Comments: 28117

2216. weatherblog 03:46 AM GMT del 29 Aprile 2009
The GFS is showing Ana and Bill forming over the next couple of weeks. That's crazy. It's been consistent... Member Since: Luglio 10, 2006 Posts: 27 Comments: 1623

2217. CatastrophicDL 03:47 AM GMT del 29 Aprile 2009
StSimons, good to know. So far I've been taking my kids on my trips, but the more extreme ones I want to do without them. How do you watch 7 kids on the Incan Trail? :o) I need to join a travel club or get a friend who wants to go the same places I do. Member Since: Settembre 3, 2007 Posts: 3 Comments: 1519

2220. Orcasystems 03:53 AM GMT del 29 Aprile 2009
Quoting StSimonsIslandGAGuy: I would recommend Havana Cuba before the embargo is lifted and it is still quaint and not overrun with tourists. I think thats where we might go this year.. give us a chance to try the new upgrades they are doing waiting for the embargo to lift. Member Since: Ottobre 1, 2007 Posts: 77 Comments: 26077

2221. KoritheMan 03:55 AM GMT del 29 Aprile 2009
Quoting weatherblog: The GFS is showing Ana and Bill forming over the next couple of weeks. That's crazy. It's been consistent... I still don't even think Ana is going to develop, in all honesty. I would give her a significantly higher chance than Bill, though. Last I saw, the GFS developed a tropical storm east of the Leeward Islands while Ana was meandering in the Caribbean. Bill quickly ended up getting ripped to shreds by strong vertical shear. The reason I'm so against the possible Bill developing is because we don't even have Ana yet, nor do we even know if we'll get Ana out of this Caribbean surge of moisture. In addition, I don't think there has ever been a tropical storm in the Atlantic basin historical record that has formed east of the Leeward Islands in May. Not even a tropical depression. Member Since: Marzo 7, 2007 Posts: 408 Comments: 15418

2223. Orcasystems 04:00 AM GMT del 29 Aprile 2009
Quoting StSimonsIslandGAGuy: Circumventing the embargo is easy. All you have to do is have a piece of paper for the Cuban customs people to stamp instead of your passport. We flew to Mexico City, and from there to Havana. Easy as pie. Or... be a Canadian :) Member Since: Ottobre 1, 2007 Posts: 77 Comments: 26077

2224. Orcasystems 04:00 AM GMT del 29 Aprile 2009
OK, the way I see it now.... Sam will track across the Southern tip of Florida.. then up the westcaost of Florida, causing massive surf (for SurfMom) in Tampa, prior to landfall... then back into the GOM to recover...and then off to Destin :) Member Since: Ottobre 1, 2007 Posts: 77 Comments: 26077

2227. weatherblog 04:03 AM GMT del 29 Aprile 2009
Quoting KoritheMan: I still don't even think Ana is going to develop, in all honesty. I would give her a significantly higher chance than Bill, though. Last I saw, the GFS developed a tropical storm east of the Leeward Islands while Ana was meandering in the Caribbean. Bill quickly ended up getting ripped to shreds by strong vertical shear. The reason I'm so against the possible Bill developing is because we don't even have Ana yet, nor do we even know if we'll get Ana out of this Caribbean surge of moisture. In addition, I don't think there has ever been a tropical storm in the Atlantic basin historical record that has formed east of the Leeward Islands in May. Not even a tropical depression. I know that. I just find it strange that the GFS is showing that this early. Whether or nor Ana or Bill forms, it's still interesting to see. If anything it's a good indicator that we may have a busy hurricane season coming up very soon. Member Since: Luglio 10, 2006 Posts: 27 Comments: 1623

2228. KoritheMan 04:05 AM GMT del 29 Aprile 2009
Quoting Orcasystems: OK, the way I see it now.... Sam will track across the Southern tip of Florida.. then up the westcaost of Florida, causing massive surf (for SurfMom) in Tampa, prior to landfall... then back into the GOM to recover...and then off to Destin :) Please don't construe our posts as needless drama and blatant overhype. That isn't what we're trying to do. Member Since: Marzo 7, 2007 Posts: 408 Comments: 15418

2229. KoritheMan 04:08 AM GMT del 29 Aprile 2009
Quoting StSimonsIslandGAGuy: Those are good points KoritheMan. There's always a first time, but before believing a forecast for something that has never happened before, the evidence...would have to be more compelling. On the other hand, Portland ME hit 92 today. They had never hit 90 in April before since records began in the late 1800s. So things that never happened before---can still happen! I'm not as strongly against Ana as I am Bill, because Ana's development could be in the Caribbean, which is the spot where we would normally expect to see tropical cyclogenesis during the month of May, not east of the Leewards. And as for the northeastern U.S. heat wave, it is rather remarkable, from a meteorological perspective. New York City was at 79F around 12:00 AM EDT two nights ago, which was warmer than Key West. That's not something that you would normally expect to see. Member Since: Marzo 7, 2007 Posts: 408 Comments: 15418

2230. weatherblog 04:14 AM GMT del 29 Aprile 2009
Quoting KoritheMan: I'm not as strongly against Ana as I am Bill, because Ana's development could be in the Caribbean, which is the spot where we would normally expect to see tropical cyclogenesis during the month of May, not east of the Leewards. And as for the northeastern U.S. heat wave, it is rather remarkable, from a meteorological perspective. New York City was at 79F around 12:00 AM EDT two nights ago, which was warmer than Key West. That's not something that you would normally expect to see. That's so crazy. Very strange. Member Since: Luglio 10, 2006 Posts: 27 Comments: 1623

2231. KEEPEROFTHEGATE (Mod) 04:20 AM GMT del 29 Aprile 2009
we made it to 83.1 yesterday normals are low 60's but back down into mid 50's for highs today so ya u could say its been a rollercoaster ride for sure Member Since: Luglio 15, 2006 Posts: 143 Comments: 40442

2232. Tazmanian 04:22 AM GMT del 29 Aprile 2009
commet there all way a 1st you no Member Since: Maggio 21, 2006 Posts: 5088 Comments: 111327

2234. quasigeostropic 04:25 AM GMT del 29 Aprile 2009
Computer models go through transitional periods between winter/summer(spring) and from summer to winter(fall). The equations in the computer models used for winter forecasting are different than the equations used for the summer regime. The result of such transitional periods are that models will spin up many false systems as they transition to a summer regime for example. Member Since: novembre 20, 2007 Posts: 21 Comments: 192

2235. moonlightcowboy 04:29 AM GMT del 29 Aprile 2009
Quoting quasigeostropic: Computer models go through transitional periods between winter/summer(spring) and from summer to winter(fall). The equations in the computer models used for winter forecasting are different than the equations used for the summer regime. The result of such transitional periods are that models will spin up many false systems as they transition to a summer regime for example. More "sound" reasoning! Thanks! Member Since: Luglio 9, 2006 Posts: 179 Comments: 28117

2236. CatastrophicDL 04:47 AM GMT del 29 Aprile 2009
I've got toturn in early tonight. See ya'll tomorrow. Take Care! Member Since: Settembre 3, 2007 Posts: 3 Comments: 1519

2237. Tazmanian 05:02 AM GMT del 29 Aprile 2009
the mode runs may be on too some in but am not sure if we can this get the wund shear to die down then we may have some in here but that is a big IF! hmmmm may be??? Member Since: Maggio 21, 2006 Posts: 5088 Comments: 111327

2238. HadesGodWyvern 06:41 AM GMT del 29 Aprile 2009
Joint Typhoon Warning Center Tropical Disturbance Summary (0600z 29APR) ============================================== An area of convection (96W) located at 14.4N 117.3E or 215 NM west of Manila, Philippines. Recent animated multispectral satellite imagery shows an elongated low level circulation center with deep convection near the center and broken convective banding wrapping into the southern periphery. A 2423z TRMM pass shows deep convective banding curving into the eastern flank of the system with broken convecting banding to the south. Upper level analysis shows the system is in an area of low vertical wind shear and located under the upper level ridge axis. Animated water vapor imagery shows good equatorward outflow and poleward outflow appears to be suppressed by surface ridging to the north. Maximum sustained winds near the center is 15-20 knots with a minimum sea level pressure of 1007 MB. The potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is FAIR. --- Philippines or Vietnam needs to stay on alert it is getting active in the southwestern part of the West Pacific. Member Since: Maggio 24, 2006 Posts: 43 Comments: 36686

2239. HadesGodWyvern 06:43 AM GMT del 29 Aprile 2009
Philippines Atmospheric Geophysical Astronomical Services and Administration Tropical Weather Special Advisory #2 ======================================= At 11:00 AM PhST, two low pressure areas was estimated at 220 kms east of Bicol region (13.5N 126.0E) and another low at 300 kms southwest of central Luzon (14.5N 117.0E). These two weather disturbane is expected to bring occasional rains over southern Luzon and Visayas becoming frequent over the provinces of Quezon, Camarines Norte, Comarines Sur, Catanduanes, Albay, Sorsogon, Marinduque, Masbate, and northern Sama which may trigger flash flooding. Residents in these areas are advised to take the necessary precautionary measurements. Member Since: Maggio 24, 2006 Posts: 43 Comments: 36686

2240. KoritheMan 06:59 AM GMT del 29 Aprile 2009
Moisture is beginning to make its way into the Caribbean. However, as Taz pointed out, shear levels are still substantially prohibitive, as high as 50 knots in some areas of the southwest Caribbean, where our potential tropical cyclone could develop in the coming days. Shear does seem to be gradually decreasing in the region, however, but it is still nowhere near favorable levels. Member Since: Marzo 7, 2007 Posts: 408 Comments: 15418

2241. HadesGodWyvern 08:43 AM GMT del 29 Aprile 2009
The highest maximum temperature of 46.0°C (120ºF) was recorded at Barmer (Rajasthan). === Can't imagine it being so hot, by the way this is India. Member Since: Maggio 24, 2006 Posts: 43 Comments: 36686

2242. HadesGodWyvern 08:46 AM GMT del 29 Aprile 2009
God Patrap that surgical mask photo with the "anime-like" girl in black is freaking me out. Member Since: Maggio 24, 2006 Posts: 43 Comments: 36686

2243. stoormfury 10:10 AM GMT del 29 Aprile 2009
morning although the gfs is still showing cyclogenesis in the southwest caribbean, the odds are being stacked against this possibility. there is little vorticity in the area as well as high noeth easterly wind shear of about 50-60 knots. any system which tries to form in this area will be completly destroyed. i suspect we will have to wait for the middle of may for something to happen Member Since: Agosto 22, 2006 Posts: 0 Comments: 2303

2244. Stormchaser2007 10:34 AM GMT del 29 Aprile 2009
Quoting stoormfury: morning although the gfs is still showing cyclogenesis in the southwest caribbean, the odds are being stacked against this possibility. there is little vorticity in the area as well as high noeth easterly wind shear of about 50-60 knots. any system which tries to form in this area will be completly destroyed. i suspect we will have to wait for the middle of may for something to happen Shears supposed to drop dramatically. Member Since: Giugno 9, 2007 Posts: 4 Comments: 15243

2246. Cavin Rawlins 10:57 AM GMT del 29 Aprile 2009
The 6Z GFS continues to forecast tropical development in the SW Caribbean but I'm not 100% sure the development may take place in he Caribbean. However, with wind shear forecast to be between 10-20 knots, marginal SSTs and ample moisture and lift along with anomalously low pressure the area will become a breeding ground for anything that tries to develop. The monsoon trough is a notorious feature in tropical cyclogeneisis in the Eastern Pacific and occasional (as in this case) it extends across Central America in the SW Caribbean, typically in May, June and October. The area lacks model supports except for some models which show high rainfall surrounded by broad low pressure. It has been consistent with development but inconsistent in track. The factors that support the GFS outweighs the factors that don't. Member Since: Luglio 24, 2005 Posts: 407 Comments: 19076

2247. Cotillion 11:02 AM GMT del 29 Aprile 2009
A child in Texas is the first person known to have died of swine flu outside Mexico, where it may have killed as many as 159 people. Officials in Washington gave no other details of the patient. Federal health officials had been warning the virus would probably claim lives in the US. The US earlier confirmed it was treating 64 cases of the virus. Germany became the latest country to confirm cases of the H1N1 virus, reporting three sufferers. ..Link While tragic, perspective still needed.. people sadly die in their hundreds from influenza every year. Member Since: Agosto 23, 2008 Posts: 7 Comments: 5300

2249. beell 11:16 AM GMT del 29 Aprile 2009
The power of the internet! A google for "swine flu jokes" Results 1 - 10 of about 2,090,000 for swine flu jokes. (0.11 seconds) Member Since: Settembre 11, 2007 Posts: 124 Comments: 12859

2250. Cotillion 11:24 AM GMT del 29 Aprile 2009
Quoting JFLORIDA: But a new flu, highly contagious, to which most or all people have no resistance doesn't show up every year. While you are correct in that panic obviously is not advised I would be wary of developments surrounding this. It's a H1N1 strain... most of us do have some limited resistance to this due to the fact that's the usual strain that happens every year. Of course, it's likely to have mutated so we can't be sure. If it was the H5N1 strain, we might be in more trouble. Link Member Since: Agosto 23, 2008 Posts: 7 Comments: 5300

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