A Severe Thunderstorm Watch has been issued for Jo Daviess, Stephenson, Carroll & Whiteside in IL until 4:00am Sunday morning. A Severe Thunderstorm Watch has been issued for Winnebago, Boone, Ogle, Lee, & DeKalb County in IL until 6:00am Sunday morning. The main threat these thunderstorms are heavy downpours, frequent cloud-to-ground lightning, and very large, damaging hail.
4:10am update: The threat for severe weather is quickly ending. Scattered showers and thunderstorms with some embedded small hail are moving through and exiting Rock, Winnebago, Boone & DeKalb County.
2:55am update: Thunderstorms are picking up in intensity but remain below severe limits. Heavy rain possible in Winnebago, Machesney Park, Roscoe, and South Beloit. Hail is possible near Lena and Pearl City.
2:50am update: Rain and thunderstorms are now approaching the Interstate 39 corridor south of Rockford.
2:15am update: Thunderstorms are located near Franklin Grove north to Byron. Those are moving southeast at 40mph. Another line of storms extends from Monroe through Davis and are moving southeast toward the Rockford metro area. These storms have a history of producing small hail and heavy rain.
2:00am update: Thunderstorms still capable of producing small hail were located in northern Stephenson and southern Green County. Another cell I’m watching will move through Stockton in Jo Daviess County within the next few minutes. Small hail is also possible along and south of US Route 30 in Lee County.
1:50am update: The Severe Thunderstorm Warning for Stephenson County has been cancelled. Non-severe thunderstorms were located near Forreston and just west of Orangeville and Monroe.
(1:34 AM) nwsbot: DVN: Freeport [Stephenson Co, IL] law enforcement reports HAIL of pea size (E0.25 INCH) at 01:30 AM CDT — hail was covering the road.
1:30am update: The thunderstorm in Stephenson County will also affect northern Ogle County an southwest Winnebago County.
1:20am update: A Severe Thunderstorm Warning is in effect for Stephenson County until 2:15am. This storm may produce hail greater than quarter-size. Locations affected include Pearl City, southern Freeport, Ridott, Baileyville, and German Valley.
1:05am update: Thunderstorms are now moving through Warren, Stockton, and Mount Carroll. A cell moving toward Pearl City city may contain pea-size hail.
12:45am update: The Severe Thunderstorm Warning has expired for northwestern Jo Daviess County.
12:30am update: The leading edge of rain and thunder is entering Jo Daviess, Carroll, and central Whiteside County.
12:00am update: A Severe Thunderstorm Warning has been issued for extreme northwestern Jo Daviess County until 12:45am.
11:30pm update: Most of the rain and thunder is west of the Mississippi River. The leading edge has entered western Whiteside County. The general track of the storms are east/southeast. Parts of eastern Iowa have experienced golf ball to tennis ball sized hail.
9:45pm: Scattered showers and thunderstorms have developed in eastern Iowa and are moving east/southeast along a frontal boundary. The main threat with any thunderstorm that develops will be very heavy downpours, frequent cloud-to-ground lightning, and very large, damaging hail.
This post was written by Joe Astolfi on March 31, 2012