HEAVY ACCUMULATIONS OF ICE CAN BRING DOWN TREES AND POWERLINES...AS
WELL AS TOPPLE UTILITY POLES AND COMMUNICATION TOWERS. ICE CAN
DISRUPT COMMUNICATIONS AND POWER FOR DAYS WHILE UTILITY COMPANIES
REPAIR EXTENSIVE DAMAGE. EVEN SMALL ACCUMULATIONS OF ICE CAN BE
EXTREMELY DANGEROUS TO MOTORISTS AND PEDESTRIANS. BRIDGES AND
OVERPASSES ARE PARTICULARLY DANGEROUS BECAUSE THEY FREEZE BEFORE
OTHER SURFACES.

FREEZING RAIN IS THE RESULT OF PRECIPITATION WHICH INITIALLY FALLS
AS SNOW...THEN ENCOUNTERS A LAYER OF WARM AIR WHICH MELTS THE SNOW
CHANGING IT TO RAIN. THE RAIN THEN FREEZES AS IT ENCOUNTERS BELOW
FREEZING AIR AT OR NEAR THE SURFACE CREATING A FILM OF ICE. 

MOST OF THE UNITED STATES RECEIVES LESS THAN 10 HOURS OF FREEZING
RAIN ANNUALLY WITH THE HIGHEST FREQUENCY IN THE SAINT LAWRENCE RIVER
VALLEY WHERE OVER 40 HOURS OF FREEZING RAIN ARE OBSERVED ANNUALLY.

THE NATIONAL WEATHER SERVICE ISSUES ICE STORM WARNINGS FOR 
PENNSYLVANIA WHEN SIGNIFICANT ICE ACCUMULATIONS ARE EXPECTED AND 
WINTER WEATHER OR FREEZING RAIN ADVISORIES FOR ANY ICE ACCRETION 
WHICH ALSO INCLUDES FREEZING DRIZZLE. THE POCONOS IN NORTHEAST 
PENNSYLVANIA ARE MOST SUSCEPTILE TO ICE STORMS WITH THE MOST 
RECENT STORMS OCCURRING IN JANUARY 2003 AND 2005.