Meterology help?

Question

Describe atmospheric conditions conducive to tornado formation. What is the difference between a “tornado watch and torando warning

Answer 1

Favorable Conditions:

These things are favorable for tornado formation:

- Winds that change direction with altitude.  Specifically, they chance direction clockwise with increasing height.  Typically you'll see south winds (winds blowing from south to north) to southeasterly winds at the surface and westerly winds (west to east) higher up.  This allows for the rotation in a tornado.

- Temperature instability which creates updrafts.  When the temperature decreases very quickly with height, that is an unstable profile.  Very humid air at the surface can enhance the instability.

-  There are also signs they look for that indicate a certain class of thunderstorms called 'supercells,' are likely and there are some other criteria for that which might be more info than you want to read.  But seeing such conditions come together makes it more likely to see tornados.

So typically you see these conditions along and ahead of a surface cold front.  In the U.S., this often sets up east of the Rockies.  Ahead of a front, warm moist air is drawn north near ground-level from the gulf of Mexico (the warm-humid condition which leads to great instability).  Such storms are usually along the jet stream, which gives those westerly winds aloft with the southerly surface winds for the rotation.

Tornado Watch:

Means that conditions already are possible, or are becoming favorable (see above) for tornado formation now or in the next few hours.  They usually issues these for when conditions look good over the next 4-6 hours.  There may be no tornadoes at this point, but they (Storm Prediction Center) think they are, or will become possible or even likely.

Warning:

Means a tornado has been spotted by someone on the ground, or the radar is giving strong indication that a tornado/funnel has formed.  When storms are happening, the National Weather Service will look at the storms with radars. When they see certain things happening in the storm with the radar that indicate rotation above the ground in the storm itself, they will usually issue a tornado warning in the expectation that it will actually come down to the ground.  

It's usually a pretty short warning time from when they see it on radar since it doesn't take much time for a tornado to come down from the base of a cloud.

Also, by the time they see it with the radar, 6-10 minutes may have passed since the last radar sweep, so 10 mins. may have already passed since it started. The warning may only give you a few minutes to as long as 30-45 mins advance warning depending on how close you are to the storm with the tornado signature.

Note:  The Storm Prediction Center issues tornado watches, while local National Weather Service offices issue tornado warnings.

Answer 2

A tornado watch means that conditions exist for a tornado to form. It does not imply that a tornado has been seen or one has been formed  while  tornado warning means that a funnel cloud or tornado has formed and has been spotted in your area.

Answer 3

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1.

Tornado - Wikipedia, the free encyclopedia

... distance of the audible sound depends on atmospheric conditions and topography. ... the meteorological conditions conducive to their formation; however, the step ...

en.wikipedia.org/wiki/Tornadoes - 213k - Cached

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2.

tornado: Definition and Much More from Answers.com

The atmospheric conditions required for the formation of a tornado include great ... the meteorological conditions conducive to their formation; however, the step ...

www.answers.com/topic/tornado - 259k - Cached