Understanding Tornados

Iv been pondering for a few months now weather or not to make a thread about what causes tornados and how often they hit the midwest

, also on a side note i had wanted to point out where they have been known to hit but for other places its rather rare .

for example Upstate new york had a tornado hit back in 03 or 04 . then we hear that they hit other places like organ , or even in the mountains in germany ...

so i will do my best to cover as much about them as possible begining with history of them in the US

In July 1643 Governor John Winthrop described a sort of wind gust that could have possibly been one of the first recorded tornadoes in history. Winthrop, who was ever conscious of the weather, recorded that there was a sudden gust in northeastern Massachusetts and costal New Hampshire. According to Winthrop this “gust” blew down many trees, filled the air with dust, lifted up a meetinghouse in Newbury, and killed one Indian. Because there was no weather technology in that time period we have no way of knowing whether this “gust” was a true tornado or not.

www.tornadochaser.net...

At this point in time, formation of tornadoes are not fully understood by scientists. They usually form in a giant rotating thunderstorm called a supercell. Supercells form when cold polar air meets warm tropical air. The result is a great instability caused by the rising warm air. A squall line, or narrow zone of cumulonimbus clouds forms, giving life to the tornadoes. Lightning flashes, and heavy rains and hail begin to fall. Soon after, the easiest recognizable part of the tornado, the funnel, seems to descend from the base of the cloud. In actuality, it does not, but rather the pressure within the cloud drops due to the increasing wind speeds. This is known as Bernoulli's principle. As the pressure drops, it causes moisture in the air to condense. This action continues down the spiral, giving the impression that the funnel is descending from the cloud base. In addition to the visible funnel, there is also a hissing sound, which turns into a loud roar when the tornado touches the earth.

library.thinkquest.org...
tornados in organ...

now for what causes them.. what i was tought in school was that they are normally forms when hot and cold air merge with each other causeing a vortex in the sky

Tornado conditions are caused when different temperatures and humidity meet to form thunderclouds. In the United States, warm, wet winds from the Gulf of Mexico move northward in spring and summer, meeting colder, dry Canadian winds moving southward. The place where these two winds meet is called a dry line. High, dry air coming from the north piles on top of low-moving, moist Gulf air at a height of over 10,000 feet. The warm southern winds try to rise, but the cold northern air blocks them. This clash causes the warm, trapped air to rotate horizontally between the two air masses. At the same time, the sun heats the earth below, warming more air that continues to try and rise. Finally, the rising warm wind become strong enough to force itself up through the colder air layer. When this occurs, the cold air on

library.thinkquest.org...
www.weather.com...
[yvid][/yvid]
to be able to see how amazing Tornadoes are .

Thanks for making this, Great info and i look forward to seeing this thread develop,

Small Tornado Hits Santa Rosa As Wild Storm Strikes Bay Area

sanfrancisco.cbslocal.com...

SANTA ROSA (CBS SF) – A small tornado destroyed a wood and corrugated metal shed at a business in Santa Rosa Friday morning, just hours before the powerful storm prompted a Tornado Warning for San Mateo County and knocked out power to many local PG&E customers.

The National Weather service said Friday that an Enhanced Fujita 1 tornado hit the area shortly before 10 a.m. An EF1 is characterized by a three-second burst of wind between 86 and 110 mph., which is roughly what witnesses describe hitting the Sequoia Landscaping Materials facility.

Another funnel cloud was spotted above Ocean Beach as the same system passed over San Francisco.

We don't normally get tornadoes here!

my thread
www.abovetopsecret.com...

reply to post by berkeleygal


as a native californian i didnt think it was , just asked anyway

Another headline
Tornado Tears Roof Off Building In Santa Rosa

See raw video and more to the story here
www.ktvu.com...

Well, it's approaching peak season in the spring for US's "tornado alley" With all of the other natural disasters happening, I'm kind of hoping that we won't have any devastating outbreaks on top of everything else that's been going on lately.

"Tornado Alley is a nickname given to an area in the southern plains of the central U.S. that consistently experiences a high frequency of tornadoes each year. Tornadoes in this region typically happen in late Spring and occasionally the early fall. The Gulf Coast area has a separate tornado maximum nicknamed "Dixie Alley" with a relatively high frequency of tornadoes occurring in the late fall (October through December)."

Some basic info:
www.ncdc.noaa.gov...