thunderstorm, definition of

Local storm resulting from warm humid air rising in an unstable environment. Air may start moving upward because of unequal surface heating, the lifting of warm air along a frontal zone, or diverging upper-level winds (these diverging winds draw air up beneath them). The scattered thunderstorms that develop in the summer are called airmass thunderstorms because they form in warm, maritime tropical air masses away from other weather fronts. More violent severe thunderstorms form in areas with a strong vertical wind shear that forces the updraft into the mature stage, the most intense stage of the thunderstorm. Severe thunderstorms can produce large hail, forceful winds, flash floods, and tornadoes.

• Long Term Tornado Trends
  By Paul Homewood It seems that tornadoes, or the lack of them, are back in the news at the moment.  American Meteorological Society President, Dr Marshall Shepherd, seems to think it is unfair to mention low tornado numbers, saying it … Continue...
• Salton Sea Determined to be the Source of Rotten-Egg Stench Engulfing LA
  If you live in the greater Los Angeles area, you may have noticed a certain foul stench polluting the air over the last few days. There have been concerns over the cause, and the damage that it could do. But this week the source was finally pinpointed:...
• Willis on why Piers Corbyn claims such a high success rate
  (elevated from a comment on the Putting Piers Corbyn to the test thread ) Willis Eschenbach says: Submitted on 2012/07/15 at 9:26 am Martin Gordon says: July 15, 2012 at 5:31 am I note that Piers is declaring this period … Continue reading →
• Willis on why Piers Corbyn claims such a high success rate.
  (elevated from a comment on the Putting Piers Corbyn to the test thread ) Willis Eschenbach says: Submitted on 2012/07/15 at 9:26 am Martin Gordon says: July 15, 2012 at 5:31 am I note that Piers is declaring this period … Continue reading →
• Pollution enhanced thunderstorms warm the planet?
  From the DOE/Pacific Northwest National Laboratory, something that doesn’t make much sense to me. As shown in the diagram above, thunderstorms transport heat from the lower troposphere upwards. The heat source at the base of the atmosphere (at the...
• The weekday -vs- weekend weather effect
  Hailstorms and tornadoes are more common during the weekday due to human created aerosols. By Dr. Roger Pielke Sr. New Paper “Why Do Tornados And Hail Storms Rest On Weekends” By Rosenfeld and Bell 2011 There is a new paper which … Continue...