Wednesday morning weather

5:50am Update:  Non-severe thunderstorms will continue to move through Wisconsin and Illinois this morning.  Severe weather will not be a threat but there could be a few heavier downpours which may cause some ponding on roadways early this morning.

A line of thunderstorms will continue to move east/southeast early this morning entering into western Jo Daviess county around 3:30am.  As of this update the only severe thunderstorm warning is for Lafayette county in southwest Wisconsin.  This storm will continue to move east around 15 to 20 mph and begin to affect western sections of Green county around 4am.  The storms that moved through late Tuesday evening have decreased the instability across the immediate area but some of the storms will still be capable of producing pea to quarter sized hail along with wind gusts greater than 50 mph.

There is also a noticeable gust front ahead of the main line of storms and this is just beginning to cross the Mississippi River in southwest Jo Daviess county and portions of northwest Carroll county.  Winds may pick up before the main line of storms moves through in those areas...generally southwest of Rockford.

Severe Wx Update 9-4-12

10:48pm Update: Severe T-Storm Warning allowed to expire for Winnebago, Boone, and Ogle counties. Severe T-Storm Warning still in effect for eastern Lee and southern DeKalb counties until 11:45pm. 60mph winds possible.

10:37pm Update:

Severe T-Storm Warning for DeKalb, Lee, and McHenry until 11:45pm. 60mph winds possible.

10:32pm Update: Main line of storms starting to push south. Lee and southern DeKalb counties now under the gun. Severe T-Storm Warning continues until 10:45pm.

Storm Reports:
Belvidere: Windows blown out of building.
Rockford: Power lines down at Wal-Mart on Riverside.
Woodstock: Downed tree partially blocking Banford Road, half mile west of Queen Anne.

9:58pm Update: Storm reports so far:
Freeport: 45mph wind gust
Winnebago: 45mph wind gust
Rockford: 45mph wind gust
Rockford Airport: 65mph wind gust
Burlington Airport (Walworth CO. WI): 46mph wind gust

9:48pm Update: Severe T-Storm Warning for Boone, DeKalb, Lee, McHenry, Ogle and Winnebago until 10:45pm. 60mph winds possible.

9:33pm Update:Winds gusting up to 45mph through parts of Stephenson and Winnebago Counties ahead of storms. No warnings at this time.

9:15pm Update:

...SPECIAL WEATHER STATEMENT...

AT 913 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
STRONG OUTFLOW WINDS FROM THUNDERSTORMS EXTENDING FROM 28 MILES 
NORTH OF RICHMOND TO 15 MILES NORTHWEST OF HEBRON TO DURAND TO 10 
MILES WEST OF LAKE SUMMERSET. THIS GUST FRONT WAS MOVING SOUTHEAST 
AT 45 MPH AND WILL PROCEED THE HEAVY RAIN AND THUNDERSTORMS AND 
COULD PRODUCE WIND GUSTS OF 40 TO 50 MPH. 

CITIES AND TOWNS AFFECTED...
  ROCKTON...            SOUTH BELOIT...       DURAND...
  LAKE SUMMERSET...     ROSCOE...             MACHESNEY PARK...
  ROCKFORD...           POPLAR GROVE...       PECATONICA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS MAY CAUSE SMALL BRANCHES TO BE BLOWN DOWN...AND LOOSE
OBJECTS TO BLOW AROUND.  SEEK SHELTER IN A STURDY STRUCTURE UNTIL
THESE STORMS HAVE PASSED.

9:10pm Update: Severe T-Storm Warning for Walworth (WI) until 10:30pm. Storms capable of quarter-sized hail/70mph winds.

8:47pm Update: Severe T-Storm Watch for Whiteside, Winnebago, Boone, Carroll, DeKalb, Jo Daviess, Lee, McHenry, Ogle, Stephenson until 2am.

8:38pm Update: Severe T-Storm Warning for Rock and Walworth (WI) until 9:30pm. Storms capable of quarter-sized hail/70mph winds.


8:17pm Update: Severe T-Storm Warning for Green and Rock County (WI) until 9:15pm. Storms capable of quarter-sized hail/70mph winds.

Severe T-Storm Warning for south Green (WI) until 9:15pm. Storms capable of quarter-sized hail/70mph winds.

Severe T-Storm Watch in effect for southern Wisconsin and Jo Daviess in Illinois until 11pm.

Big time heat could lead to big time storms

7:55pm Update: A Severe Thunderstorm Watch remains for Green county in Wisconsin and Jo Daviess county in Illinois until 11pm.  Severe storms crossed the Mississippi River early this evening and are now entering into southwest Wisconsin with numerous severe thunderstorm warnings along with a tornado warning for Grant county in Wisconsin.  The general motion of these storms will be to the east/southeast.  While they may weaken some it's possible they may begin to bow out closer to the stateline.  Damaging wind gusts would be primary concern especially for northwest Illinois.  Look for storms to enter into Green and Rock counties by 8:30pm and far northern Illinois by 9pm.


A Severe Thunderstorm Watch has been issued for Jo Daviess county until 11pm tonight.  The watch extends up through Wisconsin and Minnesota.  Big storms will likely remain north this evening.

2:00pm Update:  A severe thunderstorm watch will likely be issued for sections of western Wisconsin, Minnesota and northeastern Iowa as storms are expected to develop around 3pm or 4pm.  The atmosphere continues to destabilize ahead of a weak front and with such an unstable environment I wouldn't be surprised to see storms develop fairly quickly this afternoon to the north.   We'll continue to track any development to the north for a potential impact on the immediate area later this evening and overnight.

A strong cold front will move through early Wednesday afternoon not only bringing an end to the heat and humidity but also could bring a few big thunderstorms.  The flow within the jetstream remains quick from west to east across the Plains and Midwest this afternoon.  With ample sunshine today and plenty of moisture in place instability will continue to build across Wisconsin, Minnesota, Iowa and Illinois.  While the main weather player remains in the northern Plains, there are a few weak and subtle disturbances moving within the jetstream  The first looks to move through southern Minnesota and western Wisconsin later this afternoon bringing the threat for severe storms to that area around 6pm or 7pm.  There are some indications that those storms may move south and affect parts of southern Wisconsin and northern Illinois around 9pm tonight.  Further development with storm activity will be likely in the Plains late this evening ahead of the main low and cold front and could be just to the west by sunrise Wednesday as an MCS (cluster of storms) develop. 

As the front moves east Wednesday morning the threat for storms will increase by the afternoon across northern Illinois.  Despite being removed from the main forcing with the upper level low storms will remain capable of damaging wind gusts as well as hail across the immediate area. 

One important note to make is there have been a few smaller scale models that have been advertising stronger storms to the north in Wisconsin near the upper level low and in central Illinois closer to the deeper moisture.  If this were to pan out it would mean the worst would be just to the north and south of us.  Updates will continue tonight as well as Wednesday morning.  Be sure to tune in tonight to catch Meteorologist Brandon Arnold's forecast on the WTVO News at 5, 6 and 10pm and on FOX at 9pm. 

Slipping away

With Labor Day weekend behind us our eyes are set on cooler fall afternoons.  Unfortunately, it doesn't appear as if this will be happening for the next few days.  One thing, however, is for certain and that's the fact that we're losing daylight hours.  The sun rose this morning at 6:25 am and will set at 7:24 pm tonight.  By the end of September the sun will rise at 6:53 am and set at 6:39 pm.  We will have lost over an hour of daylight with a few short weeks! 

Heat and humidity return with a few storms

The Labor Day weekend usually marks the 'unofficial' end to summer but it's not going to feel like fall any time soon.  After a fairly humid Sunday expect more of the same this afternoon.  Starting the day off with full sunshine will allow temperatures to quickly rise into the middle 80s by noon and near 90 degrees later today.  While most of the day should remain quiet we'll be watching a week disturbance moving through Iowa, Minnesota and Wisconsin later this afternoon and evening.  A few pop up storms formed earlier this morning between Rochester and Minneapolis, MN with another cluster of storms developing west of Des Moines, IA.  There remains a weak area of high pressure over northern Illinois and far southern Wisconsin so that should keep most of the storm activity at bay through late afternoon.  Storms may begin to fill in from Des Moines northeast into Wisconsin by 3pm or 4pm as the mid-level disturbance moves through.  The Storm Prediction Center has highlighted sections of southern Wisconsin, northwest Illinois, Iowa, Missouri and southeastern Nebraska under a slight risk for severe weather.  If storms were to move through the area it likely wouldn't be until this evening and overnight. 

Some Fog Overnight... Very Warm & Humid Labor Day

The remnants of Isaac are moving into southern Indiana this evening. It will be warm and humid overnight under mostly clear skies. There could be some patchy fog development after midnight especially in those low lying areas outside of cities. The low will be around 67 degrees. On Labor Day it will be very warm and humid with high temperatures in the upper 80's. A few places in northern Illinois may touch on 90 degrees. A disturbance could cause some scattered showers and thunderstorms on early on Monday night.  It will be warm and humid again overnight with a low in the middle to upper 60's.  On Tuesday weak high pressure will take control of Stateline weather.  After some early morning fog, skies will be partly cloudy.  It will be hot and humid in the afternoon with a high around 90 degrees.  If the temperature reaches 90 degrees on Tuesday, there is a good chance that will be the last 90 degree or higher temperature recorded this long hot summer.  A strong cold front will swing across the area on Wednesday with a good chance of showers and thunderstorms. 
(The  extended range outlook calls for normal to slightly below average temperatures. After that, even with a warm up, it will be difficult to top 90 degrees when the average high is in the middle 70's. It is possible, but not likely)
The high on Wednesday will be in the middle 80's.  Cooler and less humid air will move into the area on Wednesday night and Thursday.  The overnight low on Wednesday night will drop into the upper 50's, and the high on Thursday will be around 78 degrees.  A couple of disturbances that drop down in the northwest flow on Friday and Saturday may cause some scattered showers and thunderstorms. By Saturday the high will only be in the low 70's.  On Sunday it will be sunny and pleasant with a high around 74 degrees.

Very Little (or NO) Rain for Northern Illinois

The remnants of Isaac are on the move. A large part of central, eastern, and southern Illinois will continue to get some good rainfall amounts overnight into Sunday morning as the low moves from near St. Louis, Missouri as of 11 pm Saturday night across southern Illinois into southern Indiana. The Stateline will be lucky if any rain falls at all overnight because the system will be passing too far to or south. Our region will be on the very northern periphery to the system with clouds from the remains of Isaac, but rainfall will  be very light. It will be mostly cloudy, and warm and humid on Sunday with a high of 83 degrees.  It will become partly cloudy on Sunday night with a low in the mid to upper 60's.  It will be very warm under partly skies on Labor Day with a high in the upper 80's.  The pattern will become more zonal after the remains of Isaac move off to the east.  There will be a good chance of showers and thunderstorms on Tuesday with a disturbance moving through the area, and a better chance on Wednesday with a cold front approaching from the plains.  The cold front will be all the way south to the Ohio river by early Thursday.  It be sunny, cooler and less humid on Thursday as high pressure moves from western Iowa early in the morning to Ohio by Friday morning.  It will be pleasant with a high in the upper 70's on Thursday and Friday.  Re-enforcing Canadian air will continue to provide very comfortable weather on Saturday.  It will be in the middle 70's on Saturday afternoon.