DEVELOPING STORY: KARK-TV is reporting three people dead and 25 people injured in Scotland, Arkansas from nighttime tornadoes. Numerous tornado warnings continue in that state at the present time. Our threat of severe is over. A few rumbly showers will occur between now and 2am. Sunshine expected Saturday. -ES

Tornado and severe weather threat is rapidly diminishing. General showers with embedded thunder and lightning will continue through 10pm. Any severe weather will be confined to the Chicago area around 10pm. -ES

Tornado Watch extended until 10pm for Boone, Walworth, and DeKalb Co.

NWS will be dropping the watch for Winnebago, Boone, Ogle and Lee but extending it to 10pm for the remaining counties and also add more counties further east across the Chicago Metro area.

Evening Update: SPC may be issuing a new Tor/Severe Watch for areas along and east of I-39 because the current watch expires at 8pm. Storm threat will gradually continue east with nightfall although isolated severe is possible (mainly east of the Rock River through 10pm). -ES

Meteorologists Aaron Brackett and Cyndi Kahlbaum are chasing this storm and will be providing us with live updates from our chase vehicle. At 4:15pm, they are headed west on US20 and the plan is for them to go south on IL26 toward Dixon. Join us on 13News at 5 & 6 for their live reports from the road!

Tornado Watch in effect for isolated tornadoes through 8pm this evening. However the main threat will be damaging straight-line wind at the onset of these storms. Areas most likely to see severe weather through 6pm will be northwest of Rockford. -ES


Posted under severe weather

This post was written by Eric Sorensen on April 30, 2010

blog_stormreports1(6:07:00 PM) nwsbot: LOT issues Severe Thunderstorm Warning [wind: 60 MPH, hail: <.50 IN] for Lee, Ogle, Winnebago [IL] till 6:45 PM CDT

6:01:56 PM)
nwsbot: DVN issues Severe Thunderstorm Warning [wind: 60 MPH, hail: <1.00 IN] for Bureau, Carroll, Henry, Stephenson, Whiteside [IL] till 7:00 PM CDT

(4:23:21 PM) nwsbot: MKX issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 1.00 IN] for Green, Rock [WI] till 4:45 PM CDT

(3:03:05 PM)
nwsbot: DVN cancels Severe Thunderstorm Warning for Jackson [IA] and Carroll, Jo Daviess, Stephenson [IL]

(2:27:37 PM)
nwsbot: MKX issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 1.00 IN] for Green, Iowa, Lafayette [WI] till 3:00 PM CDT

(2:24:35 PM) nwsbot: DVN issues Severe Thunderstorm Warning [wind: 60 MPH, hail: 1.00 IN] for Clinton, Dubuque, Jackson [IA] and Carroll, Jo Daviess, Stephenson [IL] till 3:30 PM CDT

Tornado Watch in effect for all areas through 8pm tonight. -ES


Posted under severe weather

This post was written by Eric Sorensen on April 30, 2010

Severe weather possible Tonight


outlook1230pm Update: The Storm Prediction Center in Norman, OK has updated the slight risk to a moderate risk  for parts of the viewing area for severe thunderstorms later this afternoon and into the evening hours. Strong Damaging Winds and Moderate Size Hail will be the primary threats. The storms that become well organized also obtain the threat for isolated tornadoes. That is only with the discrete, well-organized storms.
Scattered thunderstorms have already developed around central parts of Iowa and Missouri.   Early evening( 4-5pm) and later is when the threat will spread into Illinois. That is when the threat for damaging winds, heavy rainfall and large hail will be our main concern, as a possible line of strong/severe storms push through.
Thunderstorms are expected to push east out of the Rockford area and Northern Illinois after 1am.
The 13 Weather Authority will keep you updated with any watches or warnings throughout the day.

Notice, I put “possible” and not likely. It still remains to be seen whether the atmosphere can get charged enough to promote extreme thunderstorm development but it needs to be watched closely. Our 13FutureTrack Severe Weather Index shows intense thunderstorms over the Kansas City, SW Iowa area tonight. These storms could translate eastward and near the Mississippi River by daybreak Friday in a dying phase.

As a cold front sweeps through Iowa on Friday, intense thunderstorms may develop from Waterloo, Iowa, points south. These storms will race east-northeast and could be bearing down on us late in the afternoon into the evening. From the onset of the storms through 9pm storms will have a potential for large hail and isolated tornadoes. After 9pm the threat for tornadoes will wane, but a threat for damaging straight-line wind goes up. Where the storms are at this point remains a mystery. We’ll just have to see where they form during the afternoon hours of Friday. Once again, storms will likely develop just east of I-35 in Iowa during the mid to late afternoon.

Our storm threat will completely go away once the front passes around midnight Friday night. -ES


Posted under severe weather

This post was written by Eric Sorensen on April 29, 2010

A spreading oil disaster might eventually threaten Florida

This is a guest blog entry from Morgan Palmer, a Meteorologist with WBBH-TV, NBC2 in Ft. Myers, Florida
Satellite view of the Gulf of Mexico oil slick taken earlier this week

Satellite view of the Gulf of Mexico oil slick taken earlier this week

The large oil spill from the demise of the Transocean drilling rig Deepwater Horizon briefly affected Southwest Florida earlier this week with a petroleum-like smell mainly affecting coastal residents and visitors.

Since the April 20th explosion and subsequent sinking of the rig, thousands of barrels of oil have been leaking into the Gulf of Mexico.

More than 200,000 gallons per day of oil is now reported to be spewing forth from the site in the northern Gulf, and the wind and wave action is now slowly carrying the slick primarily to the northwest toward the fragile coastlines of Louisiana and possibly Mississippi.

Through early next week, that’s where the oil slick will be driven — toward the northern Gulf Coast.

Capping the wells

The disaster from the rig explosion and collapse has already released more than two million gallons of crude oil into the Gulf of Mexico.  In a crude oil leak, some of the heavier elements of the leak will sink in the waters of the Gulf, while much of it will be “lighter” and will float, creating the “slick” we’re hearing so much about.

If the leaks cannot be capped in the coming days, it’s possible a “relief well” might have to be drilled to eventually shut off the flow of oil.  That could take weeks to accomplish.

Possible future threat to Florida

If the well cannot be capped, and the flow not stopped soon, then a significantly larger oil release could threaten many other areas along the Gulf of Mexico coast, possibly even Florida.

It’s very important to note that there is no imminent threat to our coastlines.

However, if there is a protracted spill — one that continues for weeks or months — many other areas in the eastern Gulf of Mexico could potentially see impacts.

The Loop Current is a warm current of water that flows through the Yucatan Channel between Mexico and the western tip of Cuba and into the Gulf offshore of Southwest Florida.

That current shifts position somewhat from time to time, but generally flows north, then west well offshore Louisiana, then southeast and east exiting through the Florida Keys and the Florida Straits into the Atlantic Ocean where it is then generally known as the Gulf Stream.

The present position of the northern extent of the Loop Current isn’t that far away from the spill area.  A movement of the oil slick to the southeast a hundred miles or so would possibly place oil in that “river of water” moving toward the southern tip of Florida and the Keys at three to six feet per second, about two to four miles per hour.

The present forecast is that southeasterly winds will persist in the northern Gulf of Mexico through the weekend, pushing the oil farther away– well away from the northern edges of the Loop Current.  It’s hoped that the spill can be contained or stopped before wind currents change in coming weeks.

Impacts to Southwest Florida from a protracted spill

I think it’s very fortunate that this spill did not happen even one month earlier, when wind and wave action could have driven it directly toward Florida.

However, any oil that eventually could get into the Loop Current could get this problem closer to our shores — within a hundred miles or less in a bad scenario.

Now that we’re entering our normal summertime weather pattern, winds will typically have a southerly component.  In most cases, that wind direction could direct wave action away, or at least parallel from our coastline, would protect us from any threat.

We are going to be entering the hurricane season soon, however.  A disturbance, tropical storm, or hurricane could impact a sheen of oil contaminants greatly, and that unlikely — yet possible — factor is impossible to predict.


Posted under weather, wildlife

This post was written by Eric Sorensen on April 29, 2010

Weather Update

windyWinds across the area will increase through out the day. Our Wind Advisory is in effect for all of Northern Illinois from 1pm to 7pm today. Expect South winds sustained up to 20-30 mph, frequent gusts up to 40 mph and random gusts around 45 mph. The winds can affect your driving especially on East/West bound roads. Also, watch out for objects being blown across the roadways. The windy conditions are a result of the storm system off to our West that will also give us a round of strong to sever storms by Friday late afternoon. Some of these storms, if they become well organized could produce large hail and damaging winds. sevwxThe Storm Prediction Center in Norman, OK still has us under a slight risk for tomorrow. We will definitely keep you updated with any new information when it becomes available.


Posted under weather

This post was written by Cyndi Kahlbaum on April 29, 2010

Severe ingredients for Friday night

jetstreammuggysevereindexThe Storm Prediction Center’s “day three outlook”  ominously suggested a severe weather outbreak for much of Eastern Iowa and Northern Illinois for Friday.

However, I’m not sold on this just yet. Let’s look at a few factors that come into play for this event. First, the jetstream. Models are showing a speed-max over the K.C. area Friday evening. Storms usually form out ahead of the jetstream, which puts us in a favorable spot.

Dewpoints are another factor in determining severe development. Models are all in line in bringing copious amounts of Gulf moisture up here. Getting dewpoints in the 60s will be quite a feat considering our current dewpoint is 28°. We’ll see where we stand on Thursday.

Finally, our exclusive Severe Index model is putting most of the strong/severe stuff downstate on Friday evening which brings me to another thing: This is coming through during the evening/overnight. While overnight severe events are more common in the summertime, this time of year we really lack a lot of instability during the night…and the models are already showing puny amounts of CAPE (convective potential energy), the stuff you need to get storms to form. Right now it appears that straight-line wind will be the main threat with a very low threat of hail and tornadoes.

I am going to side with our FutureTrack model right now as it seems the most convective energy will be lagging in South-Central Illinois. Crazy things have happened and will continue to monitor the latest model guidance tonight and tomorrow. -ES


Posted under severe weather

This post was written by Eric Sorensen on April 28, 2010

Possible Severe Weather

day3otlk_0730A couple of the latest observation models are handing us all the right ingredients for the potential to have severe weather late Friday into Friday night. As the next system rolls in, south surface winds will pick-up, increasing our moisture and that will lead our dew point into the low to mid 60s. This will cause our atmosphere to become moderately unstable into Friday afternoon. Storms will start to form in the warm sector (see surface map) and along the leading edge of the approaching cold front.

Surface Map

Surface Map

The main threats we’re seeing as of now include large hail, damaging winds and possibly tornadoes with the most organized storms. The 13 Weather Authority will keep you up to date with the latest information about Friday’s severe weather.


Posted under weather

This post was written by Cyndi Kahlbaum on April 28, 2010

How one TV station dealt with disaster

This is a documentary video of how the NBC station in New Orleans dealt with Katrina.


Posted under tropical weather

This post was written by Eric Sorensen on April 27, 2010

How does frost form?

frost2frostA Frost Advisory is in effect for all of Northern Illinois and Southern Wisconsin tonight. With clear skies and light wind, frost is almost a certainty in the region tonight. But have you ever really wondered why frost forms to begin with? What we don’t see in the air that we breathe is the water vapor/molecules. We term this as humidity in the weather department. On any given day, water molecules are moving all around us. In warmer days, the molecules are moving faster. In colder days, the molecules are slower. When temperatures get down to freezing the molecules freeze on contact with the ground to form frost.

What’s interesting about this process is that it can happen even when temperatures aren’t officially at or below freezing. Our official temperatures are taken in cotton region shelters which are 5-10 feet above the ground. Cold air is more dense than warm air so it sinks, meaning that with a 37° air temperature, we can have 32° temperatures at ground-level.

Any frost will go away immediately with the presence of sunshine Wednesday morning so if you’re covering plants make sure to remove the protection as soon as the sun comes up.


Posted under cold blast

This post was written by Eric Sorensen on April 27, 2010

Wildlife & Weather

Spring is in full force and there’s no better time to get outside, enjoy the weather, and do some wildlife watching! And you don’t have to live in the country to do it. There’s an amazing diversity of wildlife in the suburbs — and even in the inner city. Fill a bird feeder, plant some flowers, or put out a birdbath and you’ll attract all sorts of birds, butterflies and other backyard wildlife. If you don’t have your own garden space, just head to the local city park to discover your wild neighbors. You can get more tips on wildlife watching from National Wildlife Federation at


Wildlife and Weather April 2010 Video


Posted under weather, wildlife

This post was written by Eric Sorensen on April 27, 2010