Tim's Weather World: Daylight Savings Time Can Kill You

Those of us who work the early shift can come to dread the return to daylight savings time.  The sun will soon set later making it tougher to nod off to sleep when your bedroom is still illuminated by the strengthening spring sun.  While that might not garner much sympathy from “normal” shift workers, there are even more serious consequences associated with the shift.

sun.gifAccording to a study in the New England Journal of Medicine, there is a 6 to 10% jump in the number of heart attacks during the first three workdays following the change to daylight savings time.

According to a study in the journal Sleep and Biological Rhythms, men are more likely to commit suicide during the first three weeks after the time change compared to any other time of the year.

According to the journal Sleep Medicine, the number of traffic accidents across the United States peaks on the Monday following the time change.

Last but not least, nutritionists say you can pack on a few more pounds during daylight savings time as your body adjusts to your new eating rhythm.

We have gained a little over two and a half hours sunlight since just the start of 2010.  The spring equinox is only ten days away.  It occurs at 12:32 pm on March 20th.  The longest day of the year will occur on the summer solstice which occurs on June 21st.

I think I will take a nap.




T-storms pepper parts of area with hail; powerful winds, more rain come next, targeting area late Friday into the weekend

For a second consecutive day, spring warmth dominated Chicago’s weather scene Thursday. In all but lakeside and some far north suburban locations, temperatures sailed back to 60-degrees and even higher in spots. By at 3:51 p.m. the reading at O’Hare had reached 60 degrees. Temperatures proceeded to 62 degrees at Midway with Marseilles, well southwest of the city, winding up with the area’s warmest Thursday reading of 66-degrees. Kankakee and Oswego were close behind tallying 64-degree highs. The mild readings marked the first time since November a set of days produced back to back 60s.

Warming air has consequences in the world of meteorology and Thursday was no exception. As temperatures increase, air becomes buoyant and begins ascending, cooling in the process. That’s precisely what happened Thursday. Add moisture to the mix while simultaneously positioning a pool of cooler than normal air aloft  and thunderstorm development is typically not far behind.

That was certainly the scenario Thursday afternoon and evening.  Doppler radar scans pegged northern Illinois and Indiana cloud tops at up to 35,000 ft. and reports of hail—much of it pea and marble-size—began arriving. Lightning data indicated the year’s most impressive flurry of lightning activity to date with as many as 180 cloud to ground strokes in one ten minute early evening period. Lightning and small hail were still being reported by late evening—though it was clear nighttime cooling was allowing cloud tops to come down and the rate of lightning production to slow dramatically.

Mammoth storm to deliver strong winds and new rainfall starting Friday night
Big changes likely to set Chicago’s weather on a wet, windy path won’t be apparent right away Friday. The day is to open deceptively calm. Breaks in the clouds are likely to allow some sunshine to go to work on the air mass sending  temperatures surging back into the 50s. But by late in the day Friday, the next wave of storminess is to begin making its move on the area. Clouds are to thicken and winds will begin increasing.

A formidable dome of mild air aloft is to assemble to Chicago’s north. It’s a development akin to building a dam across a river, forcing a northbound storm lifting out of the Gulf of Mexico to slow.  By Saturday, winds through 40,000 feet of the atmosphere and from the Mid-Atlantic and New England west to the Nation’s Heartland will be blowing vigorously from the east. Velocities of 50 mph or more are predicted several thousand feet above the surface and it’s not uncommon for winds at that level to make it down to the surface as gusts—especially when winds are aligned through such a deep layer of the atmosphere.

Chicago-area wind velocities are likely to build fairly expeditiously late Friday or Friday evening and to be gusting to 30 mph by late Friday night and possibly to 40 mph at times Saturday. It’s a development likely to make this year’s St. Patrick’s Day Parade a windy one in Chicago.
North Florida whacked by thunderstorms, local 5 inches rains
Powerful thunderstorms swept north and central Florida Thursday. Four reports of twisters were logged by NOAA’s Storm Prediction Center while rainfalls topped 5 inches  at Crystal River, Florida (5.34 inches) and a 4.82 inches rainfall was recorded in Ocala.

When does the sun reach 45 degrees above the horizon in Chicago?

Dear Tom,
My husband is interested in the period of the year knowing when the sun reaches at least 45 degrees above the horizon. When will that take place?

Deborah and Neil Levin

Dear Deborah and Neil,
The noon sun in Chicago finally will reach an elevation 45 degrees above the horizon, the halfway point between the horizon and the zenith, on Friday.

Over the course of the year the highest daily sun elevation varies from a low point of 24.7 degrees on the winter solstice to a peak of 71.6 degrees on the summer solstice.

At 11:51 a.m. Friday, the sun will be at an elevation of 45 degrees and remain there for about 21 minutes. At 12:02 p.m. Sept. 30, the peak sun elevation will drop below 45 degrees and not regain that 45-degree peak until 11:36 a.m. March 13, 2011.

Thunderstorm clouds

Professional photographer John Smierciak from St. John, Indiana sent us this striking picture of the Thursday’s thunderstorm. John tells us this view is looking west towards Illinois.

Thanks for the great shot John!

Photo courtesy of John Smierciak—SMIERCIAK IMAGES INC.

Thunderstorms continue to weaken and move out of the area

Shortly before 9:15 p.m. radar indicated a pronounced weakening in the thunderstorm activity that have been moving through the Chicago area. The thunderstorms should continue to weaken and they move north into Lake County and Lake Michigan. 

Earlier this evening the storms unleashed a barrage of small hail, heavy rain and produced vivid lightning displays.