Seguimento América do Norte - 2011



ecobcg

Super Célula
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Sitio das Fontes e Carvoeiro (Lagoa - Algarve)
Saraivada do tamanho de bolas de baseball, em Oklahoma:

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Video aqui
 

Vince

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23 Jan 2007
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Ontem à noite quando coloquei as as animações satélite do post anterior já suspeitava que estas tempestades seriam mortíferas. Uma depressão destas em plena época de Tornados a gerar forçamentos verticais brutais teria que acabar mal.


Tornadoes rip Alabama, Misssissippi; 17 dead in 2-day outbreak


Dozens of tornadoes and dangerous severe thunderstorms tore through the Southeast U.S. on Friday, bringing a second day of severe weather havoc to the nation. The death toll from the two-day severe blitz now stands at seventeen, with up to 100 people injured and tens of millions of dollars in property damage. NOAA's Storm Prediction Center logged 98 tornado reports yesterday, bringing the two-day total for the outbreak to 120 tornadoes. These preliminary reports are usually a 15% over-count of the actual number of tornadoes, which still means over 100 tornadoes have probably touched down during the past two days. The deadliest tornado of the outbreak hit near Prattville, Alabama at 10:55pm CDT last night, killing three people in a mobile home, and injuring four others. One of the most damaging tornadoes occurred just west of Jackson, Mississippi, when a tornado touched down just south of I-20, crossed the expressway, flipping cars and semis, then plowed through the town of Clinton. At least nine people were injured in Clinton, and extensive damage characteristic of an EF-2 tornado is apparent in damage photos.

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Figure 1. Radar reflectivity image of the Clinton, Mississippi tornado at 10:57am CDT as the twister crossed I-20 and hit the town. Note the classic hook-shaped echo of the parent mesocyclone in the rotating severe thunderstorms that spawned the tornado.

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Figure 2. Doppler radar velocity image of the Clinton, Mississippi tornado at 10:57am CDT.

On Thursday, tornadoes and deadly severe thunderstorms tore through Oklahoma and Arkansas, killing at least nine people. A EF-3 tornado hit the small town of Tushka, Oklahoma, population 350, ripping off the roof of the local high school and destroying dozens of buildings in Tushka. Two people were killed and 25 injured. The tornado moved over farmland and dissipated a short time later, but the squall line that spawned the tornado moved into Arkansas overnight, spawning severe thunderstorm winds that killed seven more people.

Virginia, North Carolina, and South Carolina under the gun today

The action shifts eastwards to southern Virgina and eastern North Carolina and South Carolina today, which NOAA's Storm Prediction Center have placed under its "moderate risk" region for severe weather. This is the same level of risk as we've seen for the past two days for this storm system, and it is very unusual for this portion of the U.S. to experience such a high severe weather risk. Tornado watches have already been posted for portions of Georgia, South Carolina, and North Carolina. You can follow today's severe weather using our severe weather page and interactive tornado map. This map now shows links to Youtube storm chaser videos of tornadoes, plus any wunderphotos taken of the storm.

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Figure 3. Satellite image from 23:32 UTC (7:32pm CDT) April 15, 2011, showing the strong low pressure system over the middle of the country that brought yesterday's severe weather outbreak. Image credit: NASA/GSFC.

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Figure 4. Water vapor satellite image from 23:15 UTC (7:15pm CDT) April 15, 2011, showing a dry, eye-like feature in the strong low pressure system over the middle of the country. This eye-like feature persisted for many hours, but was not visible on infrared or visible satellite images. According to an analysis done by Scott Bachmeier at the University of Wisconsin, the stratosphere, which has very dry air, sunk down to the 600 mb height at the center of the storm, and it is possible that dry air from the stratosphere is responsible for this eye-like feature. This is a different mechanism than how hurricanes develop eyes, and yesterday's storm had only a shallow area of low clouds with light rain near the center--nothing like an eyewall of a hurricane. Image credit: NOAA.
http://www.wunderground.com/blog/JeffMasters/article.html



 
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Quebec

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24 Fev 2011
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Boston - USA
Boa noite!!!
Por aqui volta a nevar com flocos enormes e muito vento, já ontem caíram uns bem grandes por volta das 17pm, que deixaram uns 2 cm no chão, infelizmente estou sem baterias no sensor e não sei a temperatura:( .
Este ano a neve não nos quer deixar e as árvores ainda estão sem folhas.
Que saudades de um dia de praia em Portugal!!!
 

Quebec

Cirrus
Registo
24 Fev 2011
Mensagens
21
Local
Boston - USA
Boa noite!!!
Por aqui volta a nevar com flocos enormes e muito vento, já ontem caíram uns bem grandes por volta das 17pm, que deixaram uns 2 cm no chão, infelizmente estou sem baterias no sensor e não sei a temperatura:( .
Este ano a neve não nos quer deixar e as árvores ainda estão sem folhas.
Que saudades de um dia de praia em Portugal!!!
 

Vince

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23 Jan 2007
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Braga
Tornado Season Intensifies, Without Clear Scientific Consensus on Why

KANSAS CITY, Mo. — All the warning sirens echoing across the Great Plains, Midwest and Southeast this month leave little doubt that the tornado season — which has plowed a trail of destruction through communities from Oklahoma to Wisconsin to Georgia — is off to an unusually busy start.

So far this year, tornadoes have killed 41 people and torn apart countless neighborhoods and, this weekend, one major airport.

Now, as the country braces for several more days of potentially violent weather, meteorologists say the number of April tornadoes is on track to top the current record. There have been, according to preliminary estimates, about 250 tornadoes so far this month and, in all likelihood, more are still to come, said Greg Carbin, the warning coordination meteorologist for the National Weather Service.

“It’s unusual but it does happen,” said Howard Bluestein, a meteorology professor at the University of Oklahoma who specializes in tornado research. “This isn’t a sign that the world is about to end.”

Those same experts note that drawing conclusions about the true size of, or reason for, an increase in tornado activity is difficult because historical statistics are unreliable due to changes in the way storms are tracked and measured.

Although the average number of April tornadoes steadily increased from 74 a year in the 1950s to 163 a year in the 2000s, nearly all of the increase is of the least powerful tornadoes that may touch down briefly without causing much damage. That suggests better reporting is largely responsible for the increase.

There are, on average, 1,300 tornadoes each year in the United States, which have caused an average of 65 deaths annually in recent years.

The number of tornadoes rated from EF1 to EF5 on the enhanced Fujita scale, used to measure tornado strength, has stayed relatively constant for the past half century at about 500 annually. But in that time the number of confirmed EF0 tornadoes has steadily increased to more than 800 a year from less than 100 a year, said Harold Brooks, a research meteorologist at the National Severe Storms Laboratory.

In April 1974, for example, there was a record 267 tornadoes reported, but the actual number that occurred is believed to be closer to 500.

“Today we seem to know about every single tree branch knocked down,” Mr. Carbin said. “We have eyes everywhere, and we have radar and satellite. It would be very difficult for a tornado to sneak through unnoticed.”

Tornadoes form when warm moist air combines with powerful dynamic winds inside a thunderstorm, sending a funnel cloud spinning toward the ground. They are most common in spring, typically peaking in May.

Though scientists believe that climate change will contribute to increasingly severe weather phenomena, including hurricanes and thunderstorms, there is little consensus about how it may affect tornadoes.

It remains unclear, partly because of the lack of historical data and partly because of their unpredictable nature, whether they will increase in number or strength or geographic range.

The large number of tornadoes so far may simply reflect normal variability, said Mr. Brooks.
http://www.nytimes.com/2011/04/26/us/26tornadoes.html?partner=rss&emc=rss
 

Vince

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Perspectivas de um final de dia e noite severa nalgumas regiões dos EUA, CAPE a chegar aos 5000J/kg, windshear muito forte, etc.

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Vince

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23 Jan 2007
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Está a ser um Abril violento, já é o 3º tornado outbreak (crise tornádica) do mês. Esta foi mais uma noite trágica.

Deadly Tornadoes: 82 Killed Across South, Including 61 Killed in Alabama

By LEEZEL TANGLAO and MICHAEL S. JAMES
April 28, 2011

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Deadly tornadoes, thunderstorms tore through the south Wednesday killing more than 80 people in four states, authorities said.

This is the latest round of storms to hit the region over past several days.

At least 82 deaths are being blamed on the severe weather, according to the Associated Press.

The majority of those deaths were reported in Alabama with 61 people killed – including 15 in the city of Tuscaloosa alone.

"They were telling us that it was going to be a pretty significant storm and that it has been. You can see that by the number of fatalities throughout the state," said Alabama Emergency Management Agency information manager Yasamie August.

Mayor Walter Maddox confirmed that 15 people died Wednesday in Tuscaloosa, Ala., a city of approximately 180,000 leveled by an estimated mile-wide tornado.

"I'm in my car at corner on McFarland. Milo's Hamburgers isn't there anymore," Tuscaloosa resident Phil Owen told ABC News affiliate WBMA. "Hobby Lobby [is the] only thing still standing at Woods Square Shopping Center. Big Lots, Full Moon Barbecue -- piles of garbage where those places were."

Maddox said at least a dozen city roads remain impassable and 83,000 homes were without power. Several city building including a fire station and a communication plant have been damaged.

"We have way over 100 injuries throughout the city of Tuscaloosa," Mayor Maddox said Wednesday. "We have hundreds of homes and businesses destroyed and hundreds more damaged."

Maddox said the National Guard were being dispatched to devastated areas across the state the Associated Press reported.

The University of Alabama is located in Tuscaloosa. Classes have been canceled for today.

Christopher England at the University of Alabama ran up to the roof of his building to video tape a massive tornado as it hit Tuscaloosa.

"We just saw this massive huge mile wide tornado and we didn't know where it was going. We didn't know if it was coming towards us or away from us or what," he said.

President Obama declared a state of emergency for the search and rescue response in Alabama, and Gov. Robert Bentley told WBMA he expected him to declare another one to help pay for the cleanup.

"It's very difficult to see this," Bentley told WBMA of the damage.

In confirming the state of emergency, President Obama said federal officials had their eye on the storms and would offer help as needed.

"Michelle and I extend our deepest condolences to the families of those who lost their lives because of the tornadoes that have swept through Alabama and the southeastern United States," he said in a written statement. "Our hearts go out to all those who have been affected by this devastation, and we commend the heroic efforts of those who have been working tirelessly to respond to this disaster."

August said the damage and destruction from on Wednesday's severe weather has left some Alabama residents with no place to go.

"We are opening shelters throughout the state to make sure folks who have nowhere to go, tonight, will have somewhere to go, out of the weather," said August.

Fatalities in Georgia, Mississippi and Tennessee

Crystal Paulk-Buchanan, a spokeswoman for Georgia emergency management in Atlanta, said at least nine people have been killed so far.

"We have nine confirmed statewide fatalities at this time. There are seven total in Catoosa County where tornadoes hit Ringgold, the town of Ringgold earlier. And two in Dade County," Paulk-Buchanan told ABC News Radio.

Paulk-Buchanan said officials have received more reports of damage in Merriweather, Polk and Pickens Counties.

"We've had several mobile home parks that have been reported to have received significant damage. In Pickens County, there were actually a couple of chicken houses that were destroyed and there are about 100,000 chickens that need to be rounded up," she said.

In addition, at least 11 were dead in Mississippi, ABC News confirmed.

One of the victims was an off-duty police officer in northern Mississippi, who died while shielding his daughter from a falling tree on a camping trip. She wasn't hurt.

The Associated Press reported at least one person killed in Tennessee Wednesday.

The weather system was expected to move into Georgia, Tennessee and Kentucky overnight and into the Carolinas by Thursday morning.

ABC News Radio, Mike Marusarz and the Associated Press contributed to this report.

http://abcnews.go.com/US/tornadoes-77-killed-south-including-61-killed-alabama/story?id=13474955