(5:04:22 PM) nwsbot: Local Storm Report by NWS LOT: De Kalb [De Kalb Co, IL] trained spotter reports HAIL of half inch size (E0.50 INCH) at 04:50 PM CST --
(5:04:57 PM) nwsbot: LOT continues Tornado Warning [tornado: OBSERVED, tornado damage threat: CONSIDERABLE, hail: 1.75 IN] for Grundy, Kendall, La Salle [IL] till 5:30 PM CST
(5:18:34 PM) nwsbot: Local Storm Report by NWS DVN: 3 ENE Rock Falls [Whiteside Co, IL] trained spotter reports HAIL of golf ball size (E1.75 INCH) at 04:58 PM CST -- largest slightly larger than golf balls.
(5:19:19 PM) nwsbot: Local Storm Report by NWS LOT: Marseilles [La Salle Co, IL] amateur radio reports TORNADO at 05:06 PM CST -- at the intersection of ne 30th and e 25th. electrical tower down blocking road and multiple buldings damaged. house with roof blown off. power line down on road.
7:00pm Update: Tornado Watch canceled for Stephenson and Jo Daviess counties. Will likely see a few more of these canceled early with the severe threat winding down.
4:25pm Update: Tornado Warning canceled for Whiteside County, however, a NEW Severe Thunderstorm Warning has been issued for Carroll and Whiteside counties until 5:30pm.
A Tornado Watch has been issued for all of Northern Illinois until 10pm Tuesday evening. Thunderstorms have quickly developed ahead of an area of low pressure near the Quad Cities and along and south of a warm front riding along I-88.
With the rapid development of thunderstorms many of them have turned severe, including one storm that did produce a tornado in eastern Iowa and is currently moving into western Whiteside County. There is a Tornado Warning for Whiteside County until 5pm.
Non-severe thunderstorms have developed north of the boundary producing heavy rainfall and frequent lightning. Hail would be the primary threat with those storms as they have become slightly elevated over top of a more stable air mass.