From spring back to winter in under 24 hours; 30+degree Tuesday temp plunge hardly welcome after Monday's 50s

The 52-degree high at O’Hare Monday was the city’s mildest official temperature in nearly 2 weeks (since 63-degrees Jan. 29) and offered a measure of reassurance that spring is actually NOT all that far away.

The fleeting “warmth” equaled Chicago’s normal high on March 28 and was 16-degrees above normal. A 52-degree or milder Feb. 18 high has occurred on only 18 of past 142 years

While 68% of all years since official records began in 1871 have recorded a 52-degree or warmer daytime high through February 18, only 18 of the past 142 years have seen a 52-degree or warmer temp on Feb. 18 itself.


Week’s first storm driving Monday’s biting northwest winds and sub-0 wind chills


One step out the door into Tuesday’s stinging northwest winds will leaves little doubt: our brief flirtation with spring is over for now!

Peak readings Tuesday are to register 30-degrees lower than on Monday and flurries are likely to flutter earthward from the day’s frequent cloud cover.

An intensifying storm system centered over the Upper Great Lakes is driving Tuesday’s powerful winds and widespread cloudiness. Temperatures are actually expected to lose ground as day proceeds, starting in the low 20s in the city (teens in the suburbs) and ending up in the mid teens ALL AREAS by nightfall. Single-digits are likely in many parts of the metro area by Wednesday morning.


Cloud-free Wednesday to mask storm’s approach


Skies clear Tuesday night and Wednesday may proceed nearly  cloud-free, masking meteorological developments to the west which could advance into Chicago late Thursday into Friday.


More formidable second storm to generate crippling, wind-driven 12”+ snows across sections of Nebraska and Kansas mid-week


A more significant storm system—the week’s second—eases out of the Rockies mid-week, threatening a major snowstorm across the central Plains and western Midwest.


Winter storm watches have been hoisted there and travel-crippling snows riding powerful east winds are predicted to overspread sections of Kansas, Nebraska, western Iowa and northwest Missouri Wednesday. Model forecasts indicate a foot or more of snow may fall in the hardest hit locations there, including the areas close to Omaha, Lincoln and Grand Island, Nebraska. Close to 10″ may fall at Norfolk and North Platte, also in Nebraska.


Areas to the south in Kansas won’t far much better.  Model snowfall estimates place potential accumulations near Russell at 13″ while Salina may see more than 8″ and Topeka may have to deal with a new snow cover from the storm  approaching 5″.


Storm to lift across Chicago in weakening phase, generating accumulating snow to commence after dark Thursday night


The storm is to lift toward Chicago in a weakening phase as it is forced to move into an energy and ultimately moisture-sapping high pressure to the northeast. Snow accumulations here will depend greatly on the speed with which this weakening occurs.

As things look now, it wouldn’t be surprising, to see 2 to 4″ of snow fall here—though the storm is far enough away that such a forecast should hardly be viewed as the final take on the system’s potential snowfall here.

A 2 to 4-inch accumulation would rank as the 2012-13 season’s biggest Chicago snow to date.

Snowfall appears likely to wait until after dark Thursday night to commence in Chicago and may continue into Friday morning before mixing with some sleet, drizzle or freezing drizzle and becoming lighter and more occasional.

As always with a system still days away, there are forecast uncertainties still to be resolved which may either boost or diminish potential snowfall. This underscores the need to monitor this system and future forecasts of its movement.