What information is required to provide advanced warnings of severe weather conditions?

Question

PLEASE answer. I just don't get this one.

Answer 1

To provide advanced warnings of severe weather, you have to understand what conditions are necessary to produce severe weather, then be able to predict when those conditions will be in place at the same time. By studying a severe weather event, and making note of all the conditions that are present, meteorologists are then able to look to the future and be able to predict a severe weather event when all those same conditions are present.

     Let's take a look at tornados.  To form a tornado, the atmosphere needs to be warm and moist at lower levels.  With an increase in height, the air may cool and become dryer as a layer of air moves over the lower windfield and effectively "caps" the warm low level airmass.  In addition, there needs to be winds from different directions with increasing height.  A strong southeast wind in the warm sector of a low pressure center might supply the low altitude warm moist air, a midlevel wind from the southwest might supply the cooler dry air cap, and a jet stream even higher in the atmosphere blowing from the west or northwest over the lower wind fields can be enough to cause shifting winds with height.  There also has to be lifting present.  Lift can be caused by a cold front that is wedging into the warm air mass ahead of it, or lift can be caused by thunderstorms which grow in intensity to become a supercell which punches through the midlevel cool dry cap and explodes high into the atmosphere.  

     If part of these conditions exist, meteorologists will look for the other contributing factors that are known to be present when tornados form.  Say for example, all of the conditions described above exist with the exception of the warm moist air in the lower atmosphere.  However, if daytime heating is expected to heat the air to the 80's later in the afternoon, and there is a source of moist air that is expected to be present, then the weather service may continue to monitor the conditions and then issue a severe weather watch as the day goes on and the conditions continue to develop.  

     So you see, it's the knowledge gained by observation of the conditions that cause severe weather that is the key information required to provide advance warnings of severe weather.  Meteorologists look for those conditions and issue the warnings as those conditions continue to develop.  

     I hope this helps, it's a very condensed explaination of a pretty broad and extensive subject.

     Good luck!!