URGENT – WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE CHICAGO IL
346 AM CST THU DEC 20 2012
LAKE IL-KANE-DUPAGE-COOK-KENDALL-GRUNDY-WILL-LAKE IN-PORTER-
INCLUDING THE CITIES OF…WAUKEGAN…AURORA…WHEATON…CHICAGO…
OSWEGO…MORRIS…JOLIET…GARY…VALPARAISO
346 AM CST THU DEC 20 2012
…WINTER STORM WARNING IN EFFECT FROM 3 PM THIS AFTERNOON TO
3 AM CST FRIDAY…
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WINTER STORM
WARNING FOR INTENSE SNOWFALL RATES…HIGH WINDS…REDUCED
VISIBILITY…AND BLOWING AND DRIFTING SNOW…WHICH IS IN EFFECT
FROM 3 PM THIS AFTERNOON TO 3 AM CST FRIDAY. THE WINTER STORM
WATCH IS NO LONGER IN EFFECT.
The temperature will start to drop at about 1:00 p.m. after reaching a high of about 46°F.
Snow amounts are likely to be less than 3 inches in Arlington Heights. Much of the rationale for a Winter Storm WARNING is the forecast for high winds associated with the snowfall.
The highest winds — steady at 30-34 mph with gusts from 47 to 52 mph are expected between 7:00 p.m. Thursday and 1:00 a.m. Friday. Winds will start to pickup at about 1:00 or 2:00 p.m. Thursday.
Thunder is possible all day through about 7:00 p.m.
There is a blizzard warning in North Central Illinois.
THE GREATEST POTENTIAL FOR A PERIOD OF HEAVY SNOW DURING THE
AFTERNOON AND EARLY EVENING HOURS ESPECIALLY IS NORTHWEST OF A MENDOTA
TO ANTIOCH LINE.
* TIMING…RAIN WILL CHANGE TO SNOW FROM WEST TO EAST LATE THIS
AFTERNOON INTO THIS EVENING…WITH SNOW LIKELY BEING HEAVY AT
TIMES. THE HEAVIEST SNOWFALL AND LOWEST VISIBILITY LOOKS TO
OCCUR IN THE IMMEDIATE CHICAGO METRO AREA BETWEEN 5 AND 9 PM.
SNOW WILL LINGER THROUGH THURSDAY NIGHT. VERY STRONG WINDS WILL
DEVELOP AS THE SNOW ARRIVES AND CONTINUE THURSDAY NIGHT.
* SNOW ACCUMULATION: SOME UNCERTAINTY CONTINUES WITH REGARD TO
SNOW AMOUNTS BUT CURRENT INDICATIONS ARE THAT TOTALS OF 2 TO
POSSIBLY 6 INCHES ARE LIKELY…WITH THE HIGHEST AMOUNTS FAVORED
ACROSS THE FAR NORTH AND NORTHWEST SUBURBS OF CHICAGO…AND
ACROSS NORTHEAST PORTER COUNTY INDIANA. LOCALLY HIGHER AMOUNTS
ARE POSSIBLE IF HEAVY SNOW BANDS WITH THUNDERSNOW OCCUR.
* WIND: WINDS WILL BECOME NORTHWEST AND INCREASE TO 30 TO 40 MPH
BY LATE THIS AFTERNOON AND CONTINUE THURSDAY NIGHT WITH GUSTS TO
50 TO 60 MPH EXPECTED. WINDS NEAR THE LAKE AND PORTER COUNTY
SHORELINE COULD EXCEED 60 MPH AT TIMES.
* IMPACTS…THE COMBINATION OF THE INTENSE SNOWFALL AND VERY
STRONG WINDS WILL RESULT IN GREATLY REDUCED VISIBILITIES AND
POSSIBLY NEAR BLIZZARD CONDITIONS. FALLING TEMPERATURES WILL
CAUSE ROADS TO BECOME SNOW COVERED AND TRAVEL TREACHEROUS. THIS
WILL LIKELY IMPACT THE EVENING RUSH HOUR. THE STRONG WINDS MAY
ALSO RESULT IN MINOR DAMAGE AND SPORADIC POWER OUTAGES. THE
GREATEST CHANCE FOR BLIZZARD OR NEAR BLIZZARD CONDITIONS IS NEAR
THE LAKE AND PORTER COUNTY INDIANA SHORELINE.
PRECAUTIONARY/PREPAREDNESS ACTIONS…
A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING. SIGNIFICANT AMOUNTS OF SNOW
ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN
EMERGENCY. IF YOU MUST TRAVEL…KEEP AN EXTRA FLASHLIGHT…
FOOD…AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.