Contents: Definitions
Winter Weather Safety Road Conditions
Winter Weather Statistics
Winter weather can impact all aspects of society, from travel to commerce
to utilities, and it can be life threatening. Be prepared before winter
weather hits to protect you and your family at home or on the road.
Winter Weather Definitions:
Winter Storm Watch - Conditions are favorable for hazardous
winter weather conditions including heavy snow, blizzard conditions, or
significant accumulations of freezing rain or sleet. These watches are
usually issued 12 to 36 hours in advance of the event.
Winter Storm Warning - Hazardous winter weather conditions
that pose a threat to life and/or property are occurring, imminent or
likely. The generic term, winter storm warning, is used for a combination
of two or more of the following winter weather events; heavy snow, freezing
rain, sleet and strong winds. The following event-specific warnings are
issued for a single weather hazard:
- Blizzard Warning - Sustained winds or frequent gusts
of 35 mph or greater, considerable falling and/or blowing snow reducing
visibility frequently to 1/4 mile or less for a period of three hours
or more. There are no temperature criteria in the definition of a blizzard
but freezing temperatures and 35 mph winds will create single digit
wind chills.
- Heavy Snow Warning - Snowfall of 6 inches or more
in 12 hours or less, or 8 inches or more in 24 hours or less.
- Lake Effect Snow Warning - Lake effect snowfall of
6 inches or more in 12 hours or less, or 8 inches or more in 24 hours
or less.
- Ice Storm Warning - Accumulations of 1/4 inch or
more of freezing rain.
- Heavy Sleet Warning - Accumulations of 1/2 inch or
more of sleet.
Winter Weather Advisory - Hazardous winter weather conditions
are occurring, imminent or likely. Conditions will cause a significant
inconvenience and if caution is not exercised, will result in a potential
threat to life and/or property. The generic term, winter weather advisory,
is used for a combination of two or more of the following events; snow,
freezing rain or drizzle, sleet, blowing snow.
Wind Chill Warning - Extreme wind
chills of -30oF or colder.
Wind Chill Advisory - Dangerous wind chills of
-20oF to -30oF. |
Wind Chill Temperature Chart
Click
here for a Wind Chill Calculator |
Winter Weather Safety
- Illinois
Emergency Management Agency
- Ice
Pack - promoting motorists' awareness of critical winter safety
measures
Ice Pack is comprised of the
AAA-Chicago Motor Club; National Weather Service; Illinois State
Police; Indiana State Police; American Red Cross; Illinois Department
of Emergency Management; Indiana Toll Road; Illinois State Toll
Highway Authority; Illinois Department of Transportation; and
the Indiana Department of Transportation.
- Tips on staying warm from
the Chicago Department of Public Health
- Winter
Storms...the Deceptive Killers
A Guide to Survival from the NWS and the American Red Cross
- Indiana
Winter Weather Guide
pdf format
Road Conditions:
Winter Weather Statistics
MONTHLY SNOWFALL NORMALS FOR
O'HARE (1971-2000) |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Annual |
11.3 |
8.3 |
6.0 |
1.6 |
T |
0 |
0 |
0 |
0 |
0.3 |
1.8 |
8.7 |
38.0 |
|
MONTHLY SNOWFALL NORMALS FOR
ROCKFORD (1971-2000) |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
Annual |
10.3 |
7.9 |
5.6 |
1.4 |
T |
0 |
0 |
0 |
0 |
0.1 |
2.6 |
10.8 |
38.7 |
|
|