Updated: 07/22/2009 5:21 PM KSTP.com | Print Story
By: Dave Dahl

Funnels everywhere!

After a quiet start to our severe weather season, things are starting to heat up a bit.  It has been our coolest summer in over a decade, which usually keeps severe weather to a minimum.  Even though we're still generally on the cool side of normal, the jet stream has moved just far enough to the north to put most of southern Minnesota and western Wisconsin right in the active zone.  The air aloft is still quite cool for this time of the year, but with the sun angle at its highest and the daylight still quite lengthy, the surface heats up regardless of what's going on aloft. 

This makes the atmosphere very unstable, producing violent updrafts and occasional heavy thunderstorms.  A few of the storms have been producing some weak rotation as well, which results in some very small but impressive funnels.  These are called "cold air funnels".  The mechanism that produces these funnels is much less dynamic than the ingredients that produce tornadoes, which results in much weaker rotation and storms that are much smaller in scope.  They rarely reach the ground and if they do they rarely produce any damage at all.  Many times they are associated with vigorous thunderstorms and can sometimes be mistaken as an actual tornado, but they aren't.  As with any thunderstorm, damaging winds, lightning, and hail can still be very dangerous with little if any warning, so caution is always advised!

Have a great day!

Meteorologist

Dave Dahl