Wednesday Evening Severe Weather Update

3:05am Update:  A few stronger cells have developed in Whiteside county early this morning and are currently moving northeast along I-88.  Areas impacted with be Prophetstown, Morrison, Sterling and Dixon.  These storms will be moving through central Lee county by 4am. 

2:50am Update:  There have been a few storms that have redeveloped this morning extending from Janesville southwest near Winnebago, Ridott and Byron.  These storms will continue moving northeast with frequent lightning, a few stronger wind gusts as well as heavy rain.  At this time there is no severe weather.





Storm Reports:
Winnebago - 60mph wind gust
South Beloit - 60mph wind gust
Belvidere - 55mph wind gust


1:13am Update: A High Wind Warning has been issued for Winnebago, Ogle, Lee, Boone, McHenry, and DeKalb until 3am. Winds of 60mph+ will be possible as storms continue to be scarce across northern Illinois.

12:45am Update: A gust front is developing ahead of storms to our west and moving quickly into areas from Janesville into Rockford. A gust front is a line of strong winds moving out ahead of the storm. On the radar, it's the greyish line just west of Rockford. Winds will be strong (50-60mph) and could cause some minor damage and power outages over the next couple minutes.

12:37am Update: A Severe T-Storm Warning is in effect for eastern Rock and western Walworth Counties in Wisconsin until 1:45am. Another warning remains in effect for Rock and Green until 12:45am. These storms are capable of winds up to 70mph and quarter-sized hail. The rest of the Stateline remains fairly quiet with a few scattered cells, including one moving into Ogle County.

11:57pm Update: Radar still showing storms off to our west, but some are now starting to push in the far northwest parts of the viewing area (Jo Daviess County).

No warnings at the moment, but the Stateline continues to be under a Severe T-Storm Watch until 3am. SPC says strong winds and heavy rain are still possible, even if they don't reach severe limits.

10:45pm Update: Strong storms are lining up to our west, but nothing in the Stateline just yet. Storms are moving mostly to the east with a little bit of a northerly component, so it will be a few more hours before these storms really push into the heart of the viewing area.

Most of the viewing area is under a Severe T-Storm Watch until 2 or 3am (depending on whether you're in Wisconsin or Illinois, respectively). The main threat will be strong winds up to 60 or 70mph, but some small hail has been reported with storms in Iowa.

Our live chat is up if you have any questions or storm reports. Stick with the First Warn Weather Team for the latest on any severe weather updates.

Hot conditions and storm chances continue

Wednesday will be another hot and humid day out there.  A Heat Advisory will be in effect from 11am until 10pm across most of Illinois and southern Wisconsin as a warm front lifts northeast over the area.  Temperatures will start out in the 70s during the early morning hours, but will quickly rise going into the afternoon, reaching near or just over 100 degrees.  The heat index is expected to reach into the 100-110 degree range.

After the warm front lifts northeast over the area, we will be watching a cold front out to our west start to push east towards the stateline as the area of low pressure moves across southern Minnesota and central Wisconsin.  This will bring another chance of rain/thunderstorms going into Wednesday evening and overnight into Thursday.  The front should clear out of the area by Thursday afternoon, which means the chance of storms could last through Thursday morning before the skies begin to clear out heading into the weekend.


Taking a look at the convective outlook put out by the Storm Prediction Center, some of the storms late this afternoon and through the late evening hours could be on the strong to severe side, as we are in a slight risk area for severe weather.  The biggest threats from these storms would be heavy rains, strong winds, and possible hail.  The risk of severe weather will be reduced going into Thursday morning as the cold front passes through the area late Wednesday night.  The chance of storms will be reduced heading into weekend as high pressure moves into the region on Saturday.

Ryan Kinnison - WTVO Intern

Recap of storms Tuesday morning

Right around 5am a line of strong thunderstorms moved across southern Wisconsin and northern Illinois knocking down trees and power lines causing several thousand to lose their power. 

These storms originated northwest of here in Minnesota late yesterday evening and began to gain a little momentum as they moved southeast.  A stationary front to the south helped provide the instability needed for these storms sustain themselves through not only Illinois but Indiana and Ohio as of late this morning.  Dry air aloft is something meteorologists look for when storms develop on the radar.  This is because some of that dry air, as well as stronger winds, can be transported down to the surface and can typically cause stronger winds along the leading edge of the thunderstorm.  Also, the fairly tight front edge reflectivity gradient (where the radar color changes) was noticeable also indicating that there were strong winds aloft likely being transported down to the surface. 

Warnings had been issued for southwestern Wisconsin around 3am, with warnings for Green county shortly after 4am.  As the storm continued southeast the leading edge began to bow out as in entered far northwest Winnebago county.  The strongest part of the storm moved from Beloit/South Beloit to the Roscoe/Rockton area with damaging wind gusts between 55-65 mph.  As the storm moved southeast it began to pick up a little momentum as it entered Boone and McHenry counties and winds were clocked over 65 mph in Harvard, IL.  At the same time there was further development along the southern edge of the storm as it moved through northern Ogle and DeKalb counties.  Wind gusts in those locations were also near 60 mph, if not higher.

The storms completely moved out of the viewing area around 6:30am as they continued east towards Chicago.  Some may classify this storm as a derecho, which is a long-lived wind producing storm.  In fact, the storm is now located in southern Ohio! 

For the remainder of the afternoon cloud cover may thin some with temperatures rising into the mid 80s.  With the stationary boundary still in place there may be an isolated storm or two later this afternoon, but a better chance arrives tonight, especially north, as the front lifts into Wisconsin by Wednesday morning.

Storm Photos

Marty Kasper: Sycamore

Marty Kasper: Sycamore



Marty Kasper: Sycamore

Marty Kasper: Sycamore

Patricia Cervantes: South Beloit






The following photos were taken from Harlem-Roscoe Fire Photographer Sheryl Drost

Tuesday morning updates continue

Trisha Humphreys: Belvidere

Remember to send in any severe weather reports or pictures to: weather@wtvo.com


A stalled out frontal boundary south of Rockford will act as the interstate for storms further upstream to follow.  Showers and thunderstorms near La Crosse, WI this morning will continue to travel southeast and should they hold together will move into northwest Illinois within the next couple hours.  The severe weather from earlier this morning has helped stabilize the atmosphere a little so what's coming in from the northwest isn't anticipated to be severe.

Tuesday morning weather

All severe thunderstorm warnings have expired for the viewing area.  There have been numerous reports of power outages across northern Illinois as well as reports of trees/tree branches down on roadways.  If you encounter an intersection that is without power remember to treat it as a four way stop. 


There are a few more showers/storms upstream moving out of Minnesota that may be here later this morning.  With the stalled boundary just to our southwest the storm threat will continue into the afternoon.   

(6:09:43 AM) nwsbot: Local Storm Report by NWS LOT: DE Kalb [Dekalb Co, IL] emergency mngr reports NON-TSTM WND DMG at 05:35 AM CDT -- tree and power lines down blocking intersection of bethany road and first street. winds estimated at 70 mph at kishwaukee hospital in dekalb.

(5:57:50 AM) nwsbot: Local Storm Report by NWS LOT: DE Kalb [Dekalb Co, IL] emergency mngr reports TSTM WND GST of M56 MPH at 05:40 AM CDT -- at northern illinois university.


5: 55am Update: Severe Thunderstorm Warning for Boone, Winnebago and Ogle counties has been expired.  However, the Severe Thunderstorm Warning continues for DeKalb and McHenry counties until 6:30am.  Strongest of the thunderstorms moving through through McHenry county where a 67 mph wind gust was reported in Harvard.  There have been several reports of tree branches down when the intial line came through.  Once this band passes skies will remain mostly cloudy with a few scattered showers through the morning.

(5:30:32 AM) nwsbot: LOT issues Severe Thunderstorm Warning [wind: 70 MPH, hail: <.50 IN] for Cook, De Kalb, DuPage, Kane, Kendall, Lake, McHenry, Will [IL] till 6:30 AM CDT





5:25am Update:  Strongest part of the storm now entering into western Boone county.  A Severe Thunderstorm Warning continues for Winnebago, Boone, McHenry, Ogle and DeKalb counties until 5:45am.  There have been numerous reports of wind gusts near 60 mph along with numerous reports of tree branches down.  Heads up near Belvidere, Capron, Caledonia and Poplar Grove.  These storms will continue to produce strong winds, frequent lightning and heavy rainfall.

(5:16:32 AM) nwsbot: MKX continues Severe Thunderstorm Warning [wind: 60 MPH, hail: 0.75 IN] for Walworth [WI] till 5:45 AM CDT

(5:05:39 AM) nwsbot: Local Storm Report by NWS MKX: 2 S Janesville Airport [Rock Co, WI] trained spotter reports TSTM WND GST of M52 MPH at 05:02 AM CDT -- peak gust before lost power.


(5:07:40 AM) nwsbot: MKX: Unverified/Non-NWS Report -- from Tom Purdy (via spotternetwork.org) @ 05:06 AM CDT -- (S) Other -- -- Spotter is 1 miles NNE of Afton, WI (Rock county) [42.619/-89.063] -- Large power flash 1-2 miles north of current location, power is now out at current location. (SN#12549)

(5:09:05 AM) nwsbot: Local Storm Report by NWS MKX: Janesville Airport [Rock Co, WI] awos reports TSTM WND GST of M50 MPH at 05:08 AM CDT --


(4:55:53 AM) nwsbot: Local Storm Report by NWS DVN: 1 SSW Rock City [Stephenson Co, IL] trained spotter reports TSTM WND GST of E50 MPH at 04:45 AM CDT -- estimated 50+ mph


(4:58:10 AM) nwsbot: Local Storm Report by NWS DVN: Freeport [Stephenson Co, IL] trained spotter reports TSTM WND GST of E60 MPH at 04:56 AM CDT -- received from spotter st256 who was in freeport

(5:04:56 AM) nwsbot: Local Storm Report by NWS DVN: Freeport Albertus Airpo [Stephenson Co, IL] awos reports TSTM WND GST of M58 MPH at 04:55 AM CDT --

(5:05:17 AM) nwsbot: Local Storm Report by NWS DVN: 1 N Freeport [Stephenson Co, IL] trained spotter reports TSTM WND DMG at 05:01 AM CDT -- huge tree blocking west bound lane of rt 75 near intersection of highway 26
(5:00:50 AM) nwsbot: MKX issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 0.75 IN] for Walworth [WI] till 5:45 AM CDT
(4:47:52 AM) nwsbot: LOT issues Severe Thunderstorm Watch for Boone, Cook, De Kalb, DuPage, Kane, Kendall, Lake, Lee, McHenry, Ogle, Will, Winnebago [IL] and Lake, Porter [IN] till 9:00 AM CDT


(4:42:29 AM) nwsbot: LOT issues Severe Thunderstorm Warning [wind: 60 MPH, hail: <.50 IN] for Boone, De Kalb, McHenry, Ogle, Winnebago [IL] till 5:45 AM CDT
(4:33:40 AM) nwsbot: MKX issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 0.75 IN] for Rock [WI] till 5:15 AM CDT

(4:27:25 AM) nwsbot: LOT issues STRONG THUNDERSTORMS MOVING INTO NORTHERN ILLINOIS for Boone, De Kalb, Kane, Lake, McHenry, Ogle, Winnebago [IL] till 6:30 AM CDT

(4:27:21 AM) nwsbot: Local Storm Report by NWS DVN: 1 ESE Nora [Jo Daviess Co, IL] trained spotter reports TSTM WND GST of E50 MPH at 04:26 AM CDT -- gusts 40-50+ estimated

Severe Thunderstorm Warning for Stephenson and Jo Daviess Counties until 5:15 am


Severe Thunderstorm Warning continues for Green county until 4:45am.  Storms extend from Madison southwest to near Warren in far southern Stephenson county.  Heavy rainfall and brief, gusty winds will remain possible.








MKX issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 0.75 IN] for Dane, Green, Iowa, Lafayette [WI] till 4:45 AM CDT

A line of severe thunderstorms are currently moving through southwest Wisconsin and will continue to move southeast around 45 mph.  I expect the southern edge of this line to move through Jo Daviess and western Stephenson county within the next 45 minutes.  Wind gusts near 50 mph, or greater, heavy rain and frequent lightning can be expected.

Monday Evening Severe Weather Update

It's been a fairly quiet night around the Stateline so far, but we'll still expecting showers and thunderstorms as we roll through the rest of the overnight. Current radar (around 10pm) shows showers in Wisconsin and thunderstorms firing up in Minnesota. Everything is basically moving southeast, so it's the storms in Minnesota we're keeping an eye on. Obviously, it will take some time for these storms to make to the Stateline, so it will be well after midnight before we start to see any significant activity.

While there are no watches or warnings with these storms, the possibility is still there. The Storm Prediction Center still has us under a slight risk for severe weather through the morning. The main concern is strong winds with some hail and heavy downpours which could cause some flooding concerns.

Stay with the First Warn Weather Team through the night for the latest on any developing severe weather.