Issued for the first major freeze of the winter season...for a major freeze during the growing season...and at other times when freezing temperatures are of such magnitude or duration that widespread damage to water pipes may occur.

 

Issued when when a variety of hazardous conditions are forecast to occur across the area, or when there is difficulty in determining the type of conditions which will predominate. A warning is used for winter weather conditions posing a threat to life and property.

 

A significant winter storm may affect your area, but its occurrence, location and timing are still uncertain. A winter storm watch is issued to provide 12 to 36 hours notice of the possibility of severe winter weather. A watch will often be issued when neither the path of a developing winter storm nor the consequences of the weather event are as yet well defined. Ideally, the winter storm watch will eventually be upgraded to a warning when the nature and location of the developing weather event becomes more apparent. A winter storm watch is intended to provide enough lead time so those who need to set plans in motion can do so.

Issued when wind chill values of minus 20 degrees or colder are expected which will cause exposed flesh to become quickly frostbitten or frozen.

Issued when life-threatening wind chills of -50F or colder are expected..

The apparent temperature which describes the cooling effect on exposed skin by the combination of temperature and wind, expressed as the loss of body heat. Increased wind speed will accelerate the loss of body heat. The formula to calculate wind chill is: WC=.0817(3.71 V^.5 + 5.81 - .25 v)(T-91.4)+91.4 where V=wind speed in MPH and T=temperature F..