Siberian Express producing Chicago's coldest February open in 17 years; 40+ consecutive hour run of sub-zero wind chills underway


A February hasn’t opened this cold here in the 17 years since 1996. The combination of bitterly cold temperatures, hovering at daybreak Friday near or below zero in many corners of the metro area, plus the biting west winds gusting as high as 30 mph, are producing 15 to 25-below zero wind chills—readings as challenging as any Chicagoans have encountered this season.



The first reported 0-degree or lower wind chill occurred Thursday at 8 a.m. and the expectation is a 40 or more hour string of consecutive sub-0-degree wind chills is likely to continue through midnight or a bit later Friday night in the rising temp regime predicted to take hold at that time.



New month follows Chicago’s least snowy January in 12 years and the city’s sunniest since 2002



The books closed at midnight on a January which produced only 2.6″ of snow. That amount was the lowest snow tally in a January here in 12 years and a total not even a quarter the normal of 10.8″.



The month ranked 20th least-snowy of the 128 Januarys on record since the 1884 start of the city’s official snowfall observations.



Waves of snowfall on the way; the first due Friday night


There’s a degree of historic precedent for low-snow yielding seasons through January to turn  snowier in February and March. While few snow-short seasons have actually caught up to normal snow levels, what HAS happened in roughly half of the city’s 21 least-snowy winters is that snow has fallen more frequently in the back half of the season.


The evolving pattern through the weekend and into the first half of next week certainly seems headed in that direction. Waves of snowfall—the first to arrive Friday night—are predicted with a series of Alberta Clipper-type weather systems.


Snow to come in more than one spell through next Tuesday with breaks between them


Snowfall is likely to fall in distict periods through next Wednesday, with breaks between them. There are hints some lake moisture may get involved in snow shower production on the back side of the systems predicted to sweep carious the area Friday night/Saturday and again Tuesday.


While much of the snow predicted to fall here in the coming week is to be “system snow”—the large-scale swaths of snow produced by the low pressure systems themselves— the lake snow belt of western Michigan faces the prospect of lake effect snows of some significance. Travel issues are sure to arise there as fluffy, easily-blown snow takes to the air, cutting visibilities at times.

Formidable lake snow tallies were already being reported across western Michigan late Thursday night with 9.1″ down at  Grandville,  8″ Kalamazoo; 9″ Paw Paw; 8.7″ Martin; and 8.5″ Schoolcraft. Those tallies may more than double in coming days as cold arctic air sweeps across the lake, generating more snow.



Model accumulation estimates for the Chicago area range from 2 to as much as 5″ when all bursts of snowfall are tallied


Snow won’t fall in one fell-swoop here this weekend. Instead, it’s to arrive in waves. Model estimates of the snow totals which may fall in the succession of disturbances predicted to traverse the area range from 2″ to as much as 5″.


February sees daylight increase 70 minutes here while growing 80% stronger than December sun; normal temps are on the rise


The new month of February sees daylight continue its seasonal increase. By month’s end, another 70 minutes of sunshine will be evident each day, an important factor in the 80% boost in the energy that February sunshine delivers.


The longer days and more direct sunlight allow normal daytime highs to climb from 32-degrees as the month begins to 40-degrees by its close.