Tuesday Weather Update

1:00pm Update:  The complex of thunderstorms that moved through this morning continues to exit east early this afternoon.  The associated cloud cover has helped to keep our atmosphere fairly stable while where the sunshine has been in full force out in Iowa the atmosphere is becoming more and more unstable.  Temperatures right now are in the upper 60s where in Iowa the 70s and even upper 80s can be found.  I am expecting our cloud cover to thin some as we go into this afternoon.

There is a mid-level shortwave (or disturbance) moving through Wisconsin and that will continue to dive southeast through the afternoon and evening.  The remainder of the afternoon will probably remain quiet, but some of our short term models are wanting to develop storms around 4pm or 5pm this evening.  The area that we'll watch through the day will be across southwest Wisconsin and northeast Iowa; this is likely where the storms will initiate.  The threat will be there for large hail and strong winds but an isolated tornado can't be ruled out, especially along the warm front.  Although this threat may reside a little further to the northwest.  As always, stay with us throughout the day and we'll continue to post updates right here.



Rainfall, heavy at times, will continue across northern Illinois and southern Wisconsin.  Already the upper level disturbance is moving into eastern Iowa and that has allowed new storm development between Cedar Rapids and Dubuque.  The general motion is to the southeast with these but with the rain falling on already saturated ground there may be some localized flooding concerns across northwest Illinois 

This image depicts the 850 mb moisture transport.  Basically it's where moisture is being transported within the lower level of the atmosphere.  The pink shaded area is generally associated with high rain events and notice how it covers northern Illinois and southern Wisconsin.  The amount of moisture we have in the atmosphere remains fairly high to our northwest so as this upper level low moves through there could be more heavy rainfall on the way.