By Meteorologist Paul Merzlock
Theoretically, extensive Great lakes ice cover, particularly this late in the season, may influence Springtime temperatures in Chicago. Prolonged late-season ice melt delays the warming of lake water. However, a study of lake ice coverage, including data from 1973 to present, suggests there is little or no correlation between the maximum amount of lake ice and average Spring temps. This is simply due to the surface area of the Great lakes being very small compared to large-scale air flow across the continent. The brutal winter of 1976-77 produced 94% ice coverage, but the following Spring turned out to be the warmest on record at the time. Persistent SW flow across the U.S. quickly melted the ice. Temps this Spring are forecast to be below normal, mainly due to a recurring northwesterly jet stream.
Which day of the year in Chicago has the greatest range between its record high and record low?
— Mark Gloudeman, Yorkville
The date is Jan. 20 with a remarkable temperature span of 90 degrees between its record low of 27 degrees below zero in 1985 and 63-degree record high in 1906.
A close runner-up is Dec. 24 with a range of 89 degrees between its record high of 64 degree in 1889 and record low of 25 below zero on a frigid Christmas Eve in 1983.
If this record is ever to be broken, March 4 appears to be a good candidate. With a frigid 12-below record low (1873) and a record high of 73 degrees (1983) already on the books for an 85-degree span, a reasonably reachable high of 79 degrees would elevate this date into the top spot.
This Winter has been brutal for most Midwesterners. However, it has yielded some stunning images of snow and ice. Some of the best photos are from photographer Ken Scott of northern Michigan. These ice cave snapshots were taken on Lake Michigan near Sleeping Bear Dunes National Lakeshore.
Courtesy Ken Scott http://www.kenscottphotography.com
YouTube … time-lapse clip experiments: http://www.youtube.com/user/KenScottPhotography
Here is a stunning photo of Chicago and Lake Michigan captured by Heidi Einsweiler, airborne on Friday morning.
What was a massive, solid sheet of ice on Thursday showed signs of cracking Friday due to a southwest wind and 40 degree temperatures.
Photo Courtesy of Heidi Einsweiler
Hazardous travel has developed across the Chicago area this morning as a combination of rain/sleet/snow has transitioned over to all snow and temperatures are gradually falling below freezing. Light snow has spread across the Chicago area this morning in the wake of a cold front that passed through from the north overnight. Conditions are expected to slowly improve from west to east this morning as the snow slowly departs.
High pressure is building into northeast Illinois, northwest Indiana and southeast Wisconsin this morning with gusty north to northeast winds pushing colder, drier air into our area. The high will center over the Midwest tonight and then move east allowing the return of warmer southerly flow here Sunday.
Airport visibility snow locations of light snow/fog – prinmarily central and southern portions of Chicago area at 7AM CST..
A wintry chill’s back on the scene Saturday. Gone are Friday’s mild southwest winds which propelled Chicago temperatures to a 2014 high of 47-degrees.
In their place, frigid north to northeast winds have taken over, reaching the area after a long trek down icy Lake Michigan. It’s a flow pattern which assures Saturday temps are likely to rise no higher than the low or mid 30s.
The cold air’s return is to be one of finite length. Southwest winds are to strengthen Sunday, reintroducing mild Pacific air Sunday afternoon and night. The 40s these winds produce are to pale in comparison to the real warmth predicted for Monday. That’s when the year’s first 50+-degree temp is to occur, with high temps likely to reach 56 at O’Hare while approaching 60-degrees in some south suburban locations.
A period of wet snow falls in the wake of Friday’s mild air
The return to colder weather has brought wet snow to sections of the Chicago area overnight. Snowfall is to exit the area expeditiously early Saturday, though the day’s north to northeast winds may bring a few lake-effect snow flurries.
Monday’s 56-degree O’Hare high to be the latest occurring “first 50-degree temp” in 32 years; only 7 of 143 years have waited so long for a 50
It’s Monday most Chicagoans are anxious to experience. That’s because it’s the first time a 50-degree or higher temperature will have occurred this year.
For a 50-degree reading to have arrived this late in the season isn’t normal operating procedure. Chicago weather record books tell us the first 50-degree temp of the season has occurred on average on or about January 28. That places Monday’s 56-degree predicted high about 6 weeks late.
Only 7 of the past 143 years have waited this late in the meteorological spring season to record a 50-degree or milder high.