Is is common for tornadoes to form in front of cold fronts?

Answer 1

Cold fronts act as a natural trigger for thunderstorm development. the cooler air pushes the warm air up enhancing lift and can lead to thunderstorm development. Under the right set of conditions (namely wind shear, CAPE ect) supercell thunderstorms can pop up in front of the cold front/squall line.

That doesnt mean tornadoes dont also form near and along warm fronts, for example the northern illinois tornado event of April 20 2004 and the very large outbreak of March 12 2006 (which produced tornadoes along both the cold and warm front)

"On the afternoon of March 1, 1997, 16 tornadoes tore through Arkansas, devastating portions of southwest, central, and northeast Arkansas (figure 1). Four of the tornadoes were responsible for all the fatalities and most of the injuries and property damage. All of the tornadoes were produced by four supercell thunderstorms (supercell thunderstorms are rotating storms that are long-lived and typically go through weakening and strengthening phases), and the four killer tornadoes were spawned by two of the supercell thunderstorms which formed ahead of a cold front."

Answer 2

Actually, it isn't common for tornadoes to form at all!

Basically a cold front provides lift, which is necessary for thunderstorms. They need something to push the air up until it can rise on its own. You also need good wind shear, which is the change in speed and direction of winds with height.

Sometimes a cold front is too much of a linear forcing for tornadoes. Basically, if the cold front is moving quickly, it will form a line of storms rather than discrete cells, which have a better chance of going tornadic.

Tornadic storms also form along dryline (separates moist air from dry air), warm fronts, and stationary fronts. Or sometimes they form from others sources of lift. In some systems that spawn tornadic storms, the cold front is a non-player, especially if there is a dryline.

Kevin B's 1 March 1997 case is an interesting example. I'm actually modeling that case now. It was a cold front, but it was very slow moving, almost stationary. Since it was so slow, there was not much linear forcing and discrete cells formed.

Also keep in mind that cold fronts often form storms that never go tornadic. Lift is necessary, but you also need moisture, instability, cap, and wind shear.

Here is a good FAQ put out by the Storm Prediction Center if you want to learn more about tornadoes. http://www.spc.noaa.gov/faq/tornado/

Answer 3

It is possible,but not always.Cold fronts have a slope of 1/40 to 1/80 compared to the warm fronts which have a value of 1/100.This gives a good lift acting as a trigger. A well marked wind shift of 45 degrees to 180 degrees,heavy rain or snow, frequent thunderstorms, severe turbulence, line squalls and icing are possible along a cold front. If the front is moving very fast,the vertical motion will also be more vigorous and the conditional instability of the uplifted warm air will be greater.Cloud systems precede the front and gusty winds will be noticed in the rear.

Answer 4

Yes, this is where the highest Storm Relative Helicity (SRH) values are. This in combination with warm and moist air, the lift from the cold front, and wind shear (necessary for supercell development), will make an area with the highest threat for tornadoes. If there is also warm and moist air coming from the Rear Flank Downdraft (RFD) in a storm, then the threat is even higher for more and stronger tornadoes.

Landspouts can also form in areas where there is a boundary because of the vertical vorticity associated with it. When this vertical vorticity is stretched out by a rapidly developing updraft, it strengthens and spins very quickly making the landspout.

Answer 5

Kevin B has answered your question well. For the reasons he listed, tornadoes can definitely form out ahead of a cold front. They can form along a number of boundaries. Supercells often form over the Great Plains off the Dryline as well. It has happened twice since April 1st of this year.

Answer 6

When the cooler air of a cold front clashes with the warm air before it and along a line ahead of the cooler air... T-storms and tornadoes are common. Especially in the south and mid-west.

Answer 7

Where a warm and cold front meets, in the instability.

Answer 8

No there has to be an accumulation of the both hot air and cold.

Answer 9

yes

Answer 10

no