Friday Weather Update

Rain showers continue to push off to the east this morning with partial clearing taking place.  Dew points continue to rise into the low 60s with temperatures in the upper 60s close to 70°, so it's starting to feel a little muggy outside.  The cold front stretches back through southern Minnesota into central Iowa, but at the moment doesn't appear to be too strong.  Going forecast appears to remain somewhat on tap.  I believe a good part of the day should remain dry before the front moves through late this afternoon.  As it does, storms will likely begin to pop out towards eastern Iowa (where better moisture and instability sit) and then move east in the evening.  The tornado threat appears to remain low but we could see heavy rain and gusty winds with any of the storms that do develop.  The front will continue to move to the east and south tonight causing the storms to push east of the Rockford region.  By Saturday, it appears the front will stall to the south keeping the storm threat going throughout the day.  Another element we will be watching throughout tonight and tomorrow will be the heavy rain threat.  With the stalled front just to our south, a swath of heavy rain will be likely.  We'll have to see just how far south the front will sit but as of right now it looks like right along I-88 could see locally 2"+.  If the front moves a little further to the north, that would potentially put the heaviest rain band over North-Central Illinois.  Chief Meteorologist Ty Shesky will have an afternoon update for you, so be sure to check back. 

Severe Potential this Afternoon

Rain will continue on and off through the morning as a warm front lifts north into Wisconsin.  One thing we'll be watching through the late morning/early afternoon hours is just how much clearing we'll see behind the showers.  We're already starting to see some clearing in the clouds through central Iowa and that is anticipated to spread east as the warm front lifts north.  The amount of sunshine we see later today will play a big factor on whether or not we'll get thunderstorms in the afternoon.  The Storm Prediction Center has shifted the slight risk a little further south this morning where better instability may reside.  Another factor that will play a role in storm development later today will be the strength of the front as it moves through.  We'll continue to monitor things through the morning once the rain passes and I'll try to get an update for you mid-morning!

Storms this Evening

A line of strong to severe thunderstorms moved through northern Illinois and southern Wisconsin this evening, prompting severe thunderstorm warnings for Dane and Jefferson counties. Although this is just north of the WTVO viewing area, some of us experienced brief, heavy downpours and winds in excess of 40mph at the southern end of this line. In fact, a funnel cloud was sighted two miles south of Janesville at about 6:45pm. Another report of interest was a non-rotating wall cloud in Kane county at The Landings at about 8pm.

We could see a few more showers this evening, otherwise look for partial clearing and some patchy fog by tomorrow morning.  --TS

WOW!

I'm sure many of you have already seen this yesterday, but I just can't get over the size of this sinkhole!  Tropical Storm Agatha swept across Central America earlier this week killing over 100 people and opened a 60 meter deep sinkhole in Guatemala City.  Agatha, the first named storm of the 2010 Pacific hurricane season, dumped several feet of rain in parts of Guatemala, also hitting El Salvador and Honduras.  For more information click here.

Rain Moving Out

Just a quick update: Illinois Route 23 remains closed near DeKalb and LaSalle County Line due to heavy rain that fell overnight.  A Flash Flood Warning has been extended until 2:45pm for southern DeKalb County.

Rain showers have moved out east this morning with most locations picking up around a half an inch.  A little more fell to the south and a little less to the north.  Skies will remain mostly cloudy through the day with temperatures rising into the mid 70s.  There is a weak upper level disturbance moving through the central Plains this morning which may spark off a few more showers later this afternoon.  Otherwise just look for mostly cloudy skies.  We'll get one quiet day Thursday before the weather pattern turns a little more active towards the weekend.

Flash Flood Watch Early Wednesday Morning

The NWS office in Chicago has issued a Flash Flood Watch for the entire WTVO viewing area from midnight tonight through Wednesday morning. Rainfall amounts of an inch or more will be common by morning, with some localized amounts of three or more inches. Lines and clusters of thunderstorms developing in Nebraska and Iowa this evening will push eastward overnight. These separate areas of thunderstorms could unite into one big complex of heavy rain with embedded thunderstorms as it moves across our area early Wednesday morning. Strong winds of 60mph or higher will also be a possibility.  --TS

Severe Threat Tonight

The weather pattern will become a little more active over the next couple of days with the jetstream winds pretty much right over top the Midwest and Great Lakes.  This set up will allow storm systems, not only at the surface but above, to move pretty much directly overhead the next couple of days leading to thunderstorms and heavy rainfall.  While much of this afternoon should remain quiet storms currently in southern South Dakota and eastern Nebraska will begin to move east throughout the day.  Storms will also develop in western Iowa where better instability and moisture reside.  As a result, the Storm Prediction Center will likely issue a moderate risk for severe weather with their late morning update for parts of eastern Nebraka and western Iowa.  As the storms begin to move east through the early evening, the current thinking is that they will develop into a cluster or MCS and move right overhead tonight.  With these types of storms, heavy rainfall and damaging winds would be the primary threat through Wednesday morning.  We'll keep the thunderstorm chance going through Wednesday afternoon and into Thursday with another round of rain for the weekend.  As a result, some computer model guidance is dumping close to 4" of rain by Friday across parts of the viewing area which could potentially lead to flooding problems.  Be sure to keep checking back for the latest updates through the afternoon.