Snow is falling across the Chicago Metro area early this Wednesday morning with the latest radar trends indicating the heaviest snowfall from about Highland Park in southeast Lake County to south of DeKalb to asbout Mendota in northwest La Salle County.
The snow continue into the early morning hours before tapering off from west to east across the area. Most areas should get between 4 to 8 inches of snow with lesser amounts in the 1-4 inches range well northwest and north of the city towards Wisconsin and Rockford.
With temperatures now down around freezing, untreated area roads are becoming snow-covered and slippery.
Rain changed to snow late Tuesday evening at Midway Airport and by 1am accumulated to 1.6 inches. That brings the seasonal snowfall total there to 80.8 inches the South Side airport’s third highest on record.
The top seasonal snowfalls at Midway Airport since 1928-29
1. 89.7 inches 1978-79
2. 82.3 inches 1977-78
3. 80.8 inches and counting 2013-14 (through 1am March 12)
City’s official season snowfall measured at O’Hare International Airport
So far O’Hare has received 0.4 inches of snow bringing their season’s total to 75.9 inches, officially the city’s fourth highest total for a season.
1. 89.7 inches 1978-79
2. 82.3 inches 1977-78
3. 77.0 inches 1969-70
4. 75.9 inches and counting 2013-14 (through 1am March 12)
Midway Airport was the city’s official site from 1942-1979 accounting for the identical totals in the previous snowiest seasons.
The snow is beginning to accumulate rapidly in the south portions of the Chicago Metro area
Here are the totals as of 1am
Midway 1.6 inches Season total now 80.8 inches
Romeoville (NWS office) 1.1 inches
O’Hare Airport 0.4 inches season total now 75.9 inches
Latest radar trends indicate that an area of snow is overspreading the Chicago Metro area. As the snow increases in intensity, visibilities will drop. By morning 4 to 8 inches of new snow are possible across much of the area, though light amounts in the 1 to 4 inch range are expected well west and north of the city towards Wisconsin and Rockford. Thundersnow is possible with snow falling at the rate of 1 to 2 inch an hour. Roads will be come snow-covered and slippery as travel conditions deteriorate. The snow will taper off Wednesday morning, but likely have aq high impact on the morning commute.
The mercury is dropping towards the freezing mark as snowfall increases across the Chicago area. Moderate to heavy snow will develop across most of the central and south portions of the region overnight with somewhat lighter snow north and west of the city towards Wisconsin and Rockford.
Winter storm warnings are in effect for much of the area. Total snowfall by Wednesday morning should be in the 4 to 8 inch rain in much of the immediate Chicago Metro area with amounts tapering off to the north and northwest to 1 to 4 inches.
Strong northeast winds gusting at times in excess of 40 mph will cause some blowing and drifting. During the height of the storm, visibilities will drop to 1/2 mile or less. Thunder may accompany the snow with accumulations of 1 to 2 inches an hour possible.
Travel conditions will rapidly deteriorate as the snowfall increases, setting the stage for a very difficult morning commute.
MESOSCALE DISCUSSION 0175
NWS STORM PREDICTION CENTER NORMAN OK
1152 PM CDT TUE MAR 11 2014
AREAS AFFECTED…NERN MO/SERN IA/NRN IL/NRN IND/FAR SWRN LOWER MI
VALID 120452Z – 121045Z
SUMMARY…THE PRECIP TYPE WILL CONTINUE TO TRANSITION FROM RAIN TO
SNOW FROM WEST TO EAST ACROSS THE DISCUSSION AREA. SNOWFALL RATES
ARE EXPECTED TO INCREASE TO 1 INCH/HR /LOCALLY 2 INCH/HR POSSIBLE/
OVER NERN MO AND SERN IA THROUGH 09Z…WITH THESE SNOWFALL RATES
DEVELOPING OVER NRN IL /INCLUDING THE CHICAGO METRO AREA/ INTO NWRN
IND AND FAR SWRN LOWER MI BETWEEN 06-09Z. GIVEN THE EWD TRANSITION
OF THIS STORM SYSTEM…THE HEAVY SNOWFALL RATES SHOULD DIMINISH OVER
NERN MO/SERN IA AFTER 09Z.
DISCUSSION…AT 04Z…A SURFACE LOW WAS LOCATED JUST EAST OF STL
WITH THIS LOW ATTENDANT TO A PROGRESSIVE SHORTWAVE TROUGH…
CURRENTLY MOVING EWD ACROSS NRN MO. WHILE EACH OF THESE SYNOPTIC
FEATURES WILL TRACK EWD OVERNIGHT…WITH THE SURFACE LOW DEEPENING
AND REACHING SWRN IND BY 09Z…A LARGER-SCALE TROUGH WILL AMPLIFY
SEWD ACROSS THE UPPER MS VALLEY. 90-120 METER 500-MB HEIGHT FALLS
ARE EXPECTED INTO LOWER MI AND THE LOWER OH VALLEY THROUGH 12Z.
STRENGTHENING NLY LOW LEVEL WINDS ACROSS THE DISCUSSION AREA WILL
SUPPORT COLD AIR ADVECTION TO AID IN RAIN CHANGING TO SNOW FROM WEST
TO EAST AS THE SURFACE LOW AND ATTENDANT MID LEVEL TROUGH TRACK EWD.
STRONG FORCING FOR ASCENT ATTENDANT TO THE TWO MID-LEVEL TROUGHS AND
FURTHER ENHANCED BY STRENGTHENING FRONTOGENETIC FORCING IN THE
850-700 MB LAYER FROM SERN IA/NERN MO TO SWRN LOWER MI/NRN IND
THROUGH 06-09Z WILL SUPPORT A BAND OF HEAVY SNOWFALL RATES.