Book closes on one of the hottest, driest Junes here

Brown lawns and shriveling leaves don’t lie. Weeks of hot, dry weather have taken their toll. And, while the year’s most impressive heat wave is history for the moment, June, 2005 enters the record book as the city’s second hottest and second driest June at Midway Airport in 77 years of continuous observations. The month averaged 6° above normal, a temperature level which suggests two and a half times the normal level of air conditioning in June.
For eight consecutive muggy days, highs surged above 90° at O’Hare—a June hot spell surpassed only by the 11 consecutive 90s recorded during the month in 1954.
Despite the recent heat and humidity, heavy thunderstorm rains Thursday were comparatively selective. Though 1.90″ fell at Morris and 1.08″ at Rockford, north suburban Lake Villa completed its 25 straight day without measurable rain Thursday.

Freak lightning strike injures Iowa meteorologist

Imagine working indoors at your computer and realizing you’ve somehow been struck by lightning. That’s what happened to Jeff Johnson in Des Moines, Iowa around 10:30 a.m. Wednesday morning. But, what makes the story especially intriguing is the fact that Johnson is the Warning Coordination Meteorologist at the National Weather Service Forecast Office there. He had been monitoring developing storms on the office’s radar console when a lightning strike outside the building apparently traveled indoors through electrical cables. Once inside, it made contact with Johnson and damaged the office’s Doppler radar and communications equipment employed in gathering storm spotter reports. Johnson was rushed to a local hospital but released in good condition later in the day. Incidents like this underscore the danger lightning can represent even when you’re indoors.

Wednesday afternoon update on Midwest Severe Weather potential: Still high to Chicago's west

As I pointed out in the piece we produced for today’s Chicago Tribune and this blog, the primary short-term risk for severe weather into tonight–and it’s fairly substantial–is for sections of Iowa, Minnesota and western Wisconsin–in other words, to Chicago’s west. A tornado watch has already been posted for eastern South Dakota, northwest Iowa and western Minnesota through 6PM–and additional watches are likely to become necessary later Wednesday and Wednesday night.
Isolated active thunderstorms continue to flare in sections of the Chicago metro in advance of the better organized, western Midwest storms. It’s been happening with some regularity since late Wednesday morning southwest of the city. Parts of Ford and Iroquois Counties were even placed under a severe t-storm warning earlier this afternoon. A caller to our office reported downpours late Wednesday morning southwest of Kankakee. Several more storms–but of limited areal coverage– are likely to flare on the inland-moving lake breeze this afternoon. The overall rain coverage with these storms is likely to remain limited to 15-30% of the area. Some concentrated downpours may accompany the heaviest among them–but over extremely limited sections of the area, suggesting these rains hardly amount to drought busters.
Should the Iowa/Minnesota/western Wisconsin severe weather survive once crossing the Mississippi, better organized clusters of active storms may hit closer to home over portions of the Chicago metro area late tonight and the first half of Thursday. These could prompt severe weather watches/warnings where they occur. It’s worth noting that any storms coming out of Iowa later tonight in addition to any that might form with a cold front’s approach here Thursday morning through midday, aren’t yet certainties. The ground in this area in exceptionally dry thanks to the ongoing drought. I can’t tell you the number of t-storms I’ve watched “dry up” or at least shrink in intensity and areal coverage, once they’ve encountered regions of dry soil in the past. This entire situation will be monitored as this weather situation continues to unfold and we’ll post updates if needed.
The good news out of this: cooler, drier weather follows Friday and Saturday before heat and a return to higher humdity take center stage here meteorologically later Sunday and on Monday (July 4) .
We’ll work update this blog as the situation warrants.
- Tom Skilling

Urban heat island behind soaring 90° tally at Midway

June’s been a warm month. The month is running 6° above normal and 6.9° warmer than a year ago. But, the distribution of the area’s most intense daytime heat hasn’t been uniform. The impact of Lake Michigan and variations in Chicago’s urban environment has helped produce a huge spread in the total number of 90° days at the city’s various weather observation sites. Midway Airport, with its heat retaining highly urban surroundings, leads the pack with 12 while O’Hare has just 7 on the books. But, Northerly Island’s tally of just four 90s underscores the impact of cooling lake breezes. Average June, 2005 temperatures are also illustrative. Midway’s 75.8° exceeds O’Hare’s 73.6° and Northerly Island’s 71.4°.
Wednesday’s SE winds do little to reduce humidity levels. The flow should limit lakeshore highs to 78-84°. Low 90s are likely several miles inland. A final day of 90s is due Thursday.
-Tom Skilling