Wednesday Evening Weather Update

UPDATE:

7:50

Tornado Warning counties for Dekalb and Lee county. A confirmed tornado was located south of Paw Paw or 9 miles SW of Shabbona. Moving east at 30mph.

 

(7:40:39 PM) nwsbot: LOT continues Tornado Warning [tornado: OBSERVED, hail: <.75 IN] for De Kalb, La Salle, Lee [IL] till 8:15 PM CDT ...AT 739 PM CDT...A CONFIRMED TORNADO WAS LOCATED NEAR COMPTON...OR 10 MILES NORTH OF MENDOTA...MOVING EAST AT 15 MPH.
(7:40:39 PM) nwsbot: Local Storm Report by NWS LOT: Compton [Lee Co, IL] trained spotter reports TORNADO at 07:38 PM CDT -- tornado near shaw road with tree damage.

7:38pm
(7:38:35 PM) nwsbot: DVN issues Tornado Warning [tornado: RADAR INDICATED, hail: <.75 IN] for Bureau, Whiteside [IL] till 8:30 PM CDT ...AT 738 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO WAS LOCATED NEAR HOOPPOLE...OR 17 MILES SOUTH OF MORRISON... MOVING EAST AT 35 MPH.

7:35pm
(7:34:05 PM) nwsbot: DVN issues Tornado Warning [tornado: RADAR INDICATED, hail: <.75 IN] for Bureau [IL] till 8:00 PM CDT ...AT 733 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO WAS LOCATED 7 MILES WEST OF LA MOILLE...OR 11 MILES SOUTH OF WALTON...MOVING EAST AT 30 MPH.

LOT continues Tornado Warning [tornado: OBSERVED, hail: <.75 IN] for Lee [IL] till 7:45 PM CDT ...AT 721 PM CDT...A CONFIRMED TORNADO WAS LOCATED 8 MILES EAST OF AMBOY...OR 10 MILES NORTH OF MENDOTA...MOVING EAST AT 25 MPH.
Tornado Warning for Lee county until 7:45pm near the Amboy area. Storms have been forming a long a warm front. Watching just NNE of Sublette moving east 20mph


We are basically in a 'hold' right now with thunderstorm development.  There have showers developing to the west over Eastern Iowa, which is where we thought they would initially develop, but the progression of them have been a bit slow.

The rain from this morning basically put a 'lid' on our atmosphere for the afternoon.  With the increase in moisture (rise in dew points) and sunshine we did manage to see for a time today, that helped to remove that lid on our atmosphere.  The warm front is also lifting north into central Illinois and southeast Iowa.

There has been a growth in development of showers over eastern Iowa, but they haven't grown much in height over the past hour.  The image to the left is shows the potential energy in the atmosphere, but also where there is that lid (outlined in blue).  This is a meso-analysis from the Storm Prediction Center.  The red lines indicated the amount of potential energy in the atmosphere (measured in joules per kilogram) and the blue shading indicates how much of a cap we have on the atmosphere.

What's interesting is the fact the showers over eastern Iowa now moving into northwest Illinois have had a hard time growing in height.  This may be due in part to the cap still over northern Illinois.  There is better instability south of Rockford, closer tied to the wind shift near Sterling and the warm front over central Illinois.  The clouds have moved back in late this afternoon & evening but that could actually help to reinforce the warm front further to the south.