A hot, steamy, active weather pattern

A  huge hot high pressure dome continues to be well anchored over areas to our south.  The Stateline is situated on the northern edge of a large area of blistering heat.  Our region is in the zone of the so called "Ring of Fire".  Our dew points have risen into the 70's, and it looks as if they will remain there for the entire work week. So, disturbances that move along the periphery of the high have a tremendous amount of moisture to work with.  A thunderstorm complex fired up over southeastern South Dakota, eastern Nebraska, and western Iowa earlier this evening.  It quickly evolved into a "Derecho" or "Bow Echo".  Bow echoes typically produce wind damage.  This feature has been moving almost due east across the northern two thirds of Iowa between Interstate 80 on the south edge and the Minnesota border on the north edge causing wind damage  as it moves to the east at a fairly rapid chip of 45 miles and hour.  A new SEVERE THUNDERSTORM WATCH has been issued for portions of the Stateline until 5 am.  Counties included in the watch include, Jo Daviess, Stephenson, Carroll, and Whiteside.  As of 11 pm cdt the bow echo continues to push eastward arching across Mason City, just to the west of Waterloo, through Marshalltown, and then back to the southwest through Des Moines.  It appears to be holding it's intensity as it continues to move toward northwestern Illinois producing thunderstorm winds gusting to more than 60 miles an hour.  The FirstWarn Weather Team will continue to monitor the evolving thunderstorm  complex as it gets closer to the Stateline.
By Meteorologist
Eric Nefstead