WGN Weather Center Blog

It was 18 years ago when 90-degree heat in combination with stifling humidities --
including tropical rain-forest level 80-degree dew points -- tangled with a cold front
and abnormally strong upper level winds to produce one of the Chicago area's deadliest
tornadoes in southwest suburban Plainfield. The storm, which hit around 3:50 p.m.,
claimed 29 lives and injured hundreds.

The weather is far more tranquil as Thursday dawns. However, thunderstorms threaten
as humid air surges back into area for the first time in five days this afternoon and into
early night. Rainfall produced by these storms will be welcome -- much of the area has
had little rain for nearly three weeks.

Wednesday's 83-degree high marked the 66th reading at or above 80 degrees this year.
Weather records indicate the area's final 80-degree day is still more than month away.

GUSTAV HAS GULF COAST ON EDGE

Residents of the Gulf Coast are understandably nervous as Tropical Storm Gustav --
weakened by its interaction with Haiti on Wednesday -- churns toward the Gulf, where
it threatens to become a major hurricane.

--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune

Posted by wgnweather at 9:57 PM | Permalink

Posted by wgnweather at 9:55 PM | Permalink | TrackBacks (0)

Dear Tom,

Has a tropical storm's name ever been retired?
Tom Urban Oak Park

Dear Tom,
It's happened only once and that was Tropical Storm Allison, which made landfall near
Houston on June 5, 2001. Though never achieving hurricane status, Allison, with top
winds of only 58 m.p.h., was a slow-moving and prolific rainmaker much like recent
Tropical Storm Fay. The storm brought more than 36 inches of rain to the Houston area
as it meandered for days along the northeast Texas coast. After drowning Texas,
Allison's heavy rains tracked across the Gulf Coast region and then turned northeast
into southern New England and the Canadian Maritimes. It finally headed out into the
Atlantic on June 18.

In addition to catastrophic flooding, Allison produced 23 tornadoes and was
responsible for at least 50 deaths and $3 billion in property damage.

Posted by wgnweather at 9:40 PM | Permalink

Thanks for joining us for this Wednesday edition of Before the Forecast!

For complete weather information, tune in to WGN News at 9pm and wgntv.com for Tom Skilling's Full and 7-day forecasts.

Tune in tomorrow for another edition of Before the Forecast, and as always continue
to watch WGN for more coverage: Morning, Noon & Nine.

Posted by Brandi Larsen at 7:27 PM | Permalink | TrackBacks (0)

This year's dry August weather is a stunning change from a year ago. Just 0.15 of an
inch has fallen at O'Hare in the 22 days since Aug. 5. That's just 5 percent of the
long-term average, and the driest Aug. 5-27 since the 0.14 of an inch fell in that period
in 1963. It's little wonder lawns are looking brown and area farmers are contemplating
spraying fields to counter a build-up of insects attracted to the dry weather. The
Chicago area had been doused by 9.67 inches in the same period a year ago -- 64
times as much rain! What a difference a year makes!

The dry weather increases the importance of any thunderstorms which erupt Thursday
or Thursday night. But those storms won't affect all areas -- just 30 to 50 percent of
the area may see a storm.

GUSTAV LURCHES TOWARD GULF

Hurricane Gustav threatens to travel over the Gulf of Mexico's infamous Loop Current
once clearing the Caribbean in coming days. That's an ominous development. Warm
water runs more than 2,000 feet deep in that region. It has fueled explosive
intensification in storms like Katrina in the past and threatens to turn Gustav into a
powerhouse storm with potential 100+ m.p.h. winds -- the season's strongest yet.

--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune

Posted by wgnweather at 10:21 PM | Permalink

Posted by wgnweather at 10:04 PM | Permalink | TrackBacks (0)

Hi Tom,

My wife and I are having a disagreement as to what comes first: thunder or lightning.
There is a lot riding on your answer.

-Bill & Maureen Lahtinen, Elk Grove Village, Ill.

Dear Bill and Maureen,

Lightning always occurs first -- always -- because lightning causes thunder. The
electric spark that constitutes a lightning bolt heats the air through which it passes to
at least 50,000 degrees in thousandths of a second. Explosive expansion of the air
immediately occurs, followed by cooling and sudden contraction. These events trigger
waves in the air which we interpret as thunder. The initial thunder that you hear comes
from the point on the lightning channel closest to you; the last sound comes from the
most distant point.

It will be difficult, probably impossible, to pair each lightning discharge with the
thunder that it produces when an active thunderstorm is generating very frequent
lightning strokes.

Posted by wgnweather at 9:11 PM | Permalink

Thanks for joining us for this Tuesday edition of Before the Forecast!

For complete weather information, tune in to WGN News at 9pm and wgntv.com for Tom Skilling's Full and 7-day forecasts.

Tune in tomorrow for another edition of Before the Forecast, and as always continue
to watch WGN for more coverage: Morning, Noon & Nine.

Posted by Brandi Larsen at 6:56 PM | Permalink | TrackBacks (0)

Diane Frank’s brother was out doing yard work at his home in Parker, Colorado Sunday
when this twister appeared. Thanks for bringing these photos to our attention,
Diana—and thank your brother for taking them. They’re fascinating!

Tom Skilling

Photos courtesy of Diane Frank

Posted by wgnweather at 5:04 PM | Permalink | TrackBacks (0)

It’s always wonderful to open Mark Vogan’s e-mails from the UK because they so often
include spectacular shots of that beautiful part of the world and the weather which is
going on there. Mark and his wife Karen have traveled in recent days from Scotland to
London and then on to Dover, site of the Channel Tunnel beneath the English Channel
which links the UK with the European continent. Check out his photos! Mark tells us
the weather has been clear and warm with daytime readings near 70-degrees. He
comments that the waters of the English Channel the day he Karen visited the area had
taken on the appearance of Caribbean or Mediterannean waters because of their light
blue hue. Many thanks Mark for taking the time to share these photos with us!

-Tom Skilling

Photos courtesy of Mark Vogan in the UK

Posted by wgnweather at 4:56 PM | Permalink | TrackBacks (0)