Dear Tom,

A friend in North Pole, Alaska, (260 miles north of Anchorage), indicated the temperature was 51 degrees below zero and at the same time a weather observation at nearby Eielson Air Force Base reported light drizzle. Can drizzle occur at that temperature? Can that observation be correct?

--Marty Becker, Schaumburg

Dear Marty,

It was an error. Drizzle occurring at 51 degrees below zero should have been reported as freezing drizzle (tiny liquid droplets that freeze upon contact with exposed surfaces). The larger issue is this: Is drizzle even possible at that temperature? The answer, surprisingly, is yes. The surface tension that exists in tiny water droplets is so great that it can prevent the formation of ice crystals even when the droplet is cooled far below the usual freezing point of water (32 degrees) if the droplet is in a calm, undisturbed environment. However, 50 below is pushing the theoretical limit.

This snowy shot was taken at the Steamboat Ski Resort near Steamboat Colorado.

Thanks to Diane for submitting this photo montage depicting the beauty of a foggy, early February morning in Bourbonnais.


Photo by Diane

The ground hog had his day yesterday and his bold prediction of six more weeks of winter doesn't seem like much of a threat.   Most of us could handle six more weeks of the kind of winter we have seen so far.  According to Illinois State Climatologist Jim Angel the average temperature for December/January was 33.4º for Illinois, making it at the 6th warmest December/January period on record going all the way back to 1895.  So Arctic air has been elusive this winter.  There have only been ten days with temperatures below average. Snowfall has been scarce also.  At O'Hare we would normally have 21.5" of snow by now but so far this winter we have picked up just 13.19".

We put our number crunchers to work to see if a a warm winter normally is followed by a hot summer.  We looked at the past 83 winters at Midway for consistency's sake.  Of those 83 winters, 26 had above average temperatures for the months of January and February (like this winter).  15 of those summers (months of June, July & August)  that followed had temperatures above the average of 73.2º. 

We then narrowed it down to summers that followed winters that were well above average.   This winter has been +6.8º above average.  There were four winters at least that warm and three out of the four summers that followed were also warmer than average.

         Year                     above/below avg.

   summer of 1931                   -0.5º

   summer of 1982                  +2.8º

   summer of 2001                  +3.0º

   summer of 2006                  +0.9º

So in conclusion, statistically speaking, there appears to be a correlation between a warm winter and warmer than average summer.  58% of summers following warmer than average winters were also warmer than average. 75% of summers that followed the four warmest winters  (given it is a small sample size) were also warmer than average.

Special thanks to Frank Wachowski & Richard Koeneman for their help.

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By Meteorologist Steve Kahn

Friday morning commuters, especially those in outlying areas, will have to deal with dense fog for a second morning as visibilities are expected to be a quarter mile or less. The fog is expected to lift by afternoon, but residual low cloudiness and strengthening northeast winds will keep temperatures lower than in recent days, though still well above the seasonable normal. Thursday's official high of 43 degrees at O'Hare International Airport marked the city's 37th day of at least 40 degrees since Dec. 1, the most for any winter period to date since 42 were logged in the winter of 1889-90.

Cold in Europe, Asia

While Chicago and much of the U.S. are experiencing a mild winter, severe cold is gripping portions of Europe and Asia. Scores of record lows were set Thursday spanning areas from the United Kingdom to Japan. Some of the coldest readings were in Kazakhstan where the mercury plunged to minus 35 degrees at Karaganda.

Dear Tom,

How soon can we expect our first 60-degree day of the season on average, and what is the earliest and latest date for such an occurrence?

--Nick Recchia, River Grove

Dear Nick,

Your question suggests that even in a winter as relatively mild as this one has been to date, anticipation is building for the return of spring warmth. A search for 60-degree days in Chicago winters reveals they can occur at any time from December through February, though not often. A computer sweep of the city's 141-year winter temperature data set, beginning on Jan. 1 in each year, reveals the average date for the first occurrence of a temperature of 60 degrees or higher is March 2.

But averages don't convey an accurate picture. There has been 60-degree day as early as Jan. 1 (65 degrees in 1876) and as late as April 23 (63 degrees in 1881).

By Meteorologist Paul Merzlock

Satellite imagery Wednesday night indicated a weather disturbance moving across the southwestern U.S. that is likely to evolve into a heavy snow producer over portions of the central and southern Plains on Friday. Typically this situation would have Chicagoans preparing for snow as the storm heads east. However, one necessary ingredient for a Midwestern snowstorm will be lacking: a supply of polar air, which will be absent as the Plains storm approaches the Mississippi Valley on Saturday. As a result, the Chicago area can expect little more than light rain as this system passes through late Saturday. Temperatures may be low enough Sunday to produce rain-snow mix, but no accumulations are expected.

Medium-range computer forecasts are suggesting a downturn in temperatures late next week, but no major storms are foreseen and snow prospects remain low.