North Carolina Winter Weather Preparedness Week runs from November 29 through December 5. Topic 1 is the winter 2009 - 2010 outlook and winter storm terms. The following National Weather Service statement has been only slightly modified by me:
OUTLOOK FOR THIS WINTER 2009 - 2010: MUCH OF CENTRAL NORTH CAROLINA HAS BEEN SPARED THE IMPACT OF A SIGNIFICANT WINTER STORM THE LAST SEVERAL YEARS. IN FACT, THE HEAVY SNOW WHICH FELL FROM RALEIGH EAST ON JANUARY 20TH OF LAST YEAR WAS THE FIRST HEAVY SNOW TO STRIKE THE AREA SINCE 2004. MANY OTHER LOCATIONS ACROSS CELTRAL NORTH CAROLINA RECEIVED MUCH LESS SNOW LAST YEAR. THIS WINTER, EL NINO (WARMER THAN NORMAL SEA SURFACE TEMPERATURES IN THE EQUATORIAL PACIFIC OCEAN) IS LIKELY TO BE ONE OF THE PRIMARY FACTORS INFLUENCING OUR WEATHER. EL NINO RESULTS IN AN INTENSIFIED UPPER LEVEL JET STREAM WHICH HELPS TO DRIVE PRECIPITATION AND WINTER STORMS. THE OUTLOOK FOR THIS WINTER FEATURES AN ABOVE NORMAL CHANCE FOR A COLDER THAN NORMAL WINTER. THE PRECIPITATION OUTLOOK FOR THIS WINTER CALLS FOR GOOD CHANCES OF NORMAL TO ABOVE NORMAL PRECIPITATION. IT IS TOO EARLY TO SAY HOW MUCH OF THIS PRECIPITATION WILL FALL AS SNOW OR ICE.
WINTER STORM WATCHES AND WARNINGS: WATCHES AND WARNINGS ARE ISSUED BY THE NATIONAL WEATHER SERVICE FOR POTENTIALLY LIFE-THREATENING CONDITIONS. IN WINTER, WATCHES AND WARNINGS ARE ISSUED FOR SIGNIFICANT SNOW AND / OR ICE STORMS.
WINTER STORM WATCH - ISSUED WHEN THE FOLLOWING WEATHER CONDITIONS ARE POSSIBLE WITHIN 24 TO 48 HOURS: AT LEAST 3 TO 5 INCHES OF SNOW AND / OR ICE ACCUMULATIONS OF 1/4 INCH OR MORE IN A 12 TO 24 HOUR PERIOD.
WINTER STORM WARNING - ISSUED WHEN AT LEAST 3 TO 5 INCHES OF SNOW OR ICE ACCUMULATIONS OF 1/4 INCH OR MORE ARE LIKELY WITHIN 24 HOURS. WINTER WEATHER ADVISORY - ISSUED WHEN 1 TO 3 INCHES OF SNOW OR ICE ACCUMULATIONS OF LESS THAN 1/4 INCH ARE LIKELY WITHIN 24 HOURS.
BLIZZARD WARNING - ISSUED WHEN STRONG WINDS COMBINE WITH FALLING AND / OR BLOWING SNOW TO REDUCE VISIBILITY TO ONE QUARTER MILE OR LESS FOR AT LEAST 3 HOURS. DEEP SNOW DRIFTS AND DANGEROUSLY LOW WIND CHILLS OFTEN ACCOMPANY BLIZZARD CONDITIONS.
WIND CHILL WARNING - ISSUED WHEN WIND CHILL TEMPERATURES (THE COMBINED EFFECT OF WIND AND TEMPERATURE ON EXPOSED SKIN) ARE FORECAST TO REACH 20 DEGREES BELOW ZERO OR COLDER.
PRECIPITATION TYPES:
FREEZING RAIN - FREEZING RAIN IS RAIN THAT FALLS AND FREEZES TO A COLD SURFACE SUCH AS A ROAD OR TREE, CAUSING A GLAZE OF ICE TO FORM. FREEZING RAIN FORMS WHEN SNOW FALLS THROUGH A WARM LAYER ABOVE THE GROUND, MELTS TO RAIN, THEN RE-FREEZES UPON REACHING THE GROUND, WHERE THE AIR AND GROUND-LEVEL OBJECTS ARE BELOW FREEZING. FREEZING RAIN EVENTS, OR "ICE STORMS", CAN BRING DOWN TREES AND POWER LINES, AND SEVERELY HAMPER TRAVEL. AN ICE STORM IN DECEMBER OF 2002 CRIPPLED CENTRAL NORTH CAROLINA LEAVING SOME AREAS WITHOUT POWER FOR A WEEK.
SLEET - SLEET IS RAIN THAT HAS RE-FROZEN INTO ICE PELLETS PRIOR TO REACHING THE GROUND. SLEET FORMS IN A SIMILAR MANNER TO FREEZING RAIN. HOWEVER, THE LAYER OF COLD AIR NEAR THE GROUND IS THICK ENOUGH TO ALLOW THE RAIN DROPS TO RE-FREEZE BEFORE REACHING THE GROUND. SLEET WILL BOUNCE WHEN IT STRIKES A HARD SURFACE. SLEET CAN ACCUMULATE LIKE SNOW AND MAKE A ROAD SLICK, BUT IT IS NOT AS HAZARDOUS AS FREEZING RAIN.
BLIZZARD - A BLIZZARD OCCURS WHEN WINDS 35 MPH OR GREATER COMBINE WITH FALLING OR BLOWING SNOW TO REDUCE VISIBILITY TO OR BELOW ONE QUARTER MILE CAUSING WHITE-OUT CONDITIONS. PEOPLE OUT IN BLIZZARDS CAN QUICKLY BECOME DISORIENTED FROM THE COLD, SNOW AND WIND, AND LOSE THEIR WAY WHEN ONLY SEVERAL YARDS FROM THEIR HOME OR CAR.
FLURRIES - THE TERM FLURRIES REFERS TO VERY LIGHT SNOW OR SNOW THAT OCCURS FOR A SHORT TIME PERIOD ONLY CAUSING A LIGHT DUSTING AT BEST.
WIND CHILL - WIND CHILL TEMPERATURE IS THE "FEEL-LIKE" TEMPERATURE DENOTING THE COMBINED EFFECT OF WIND AND TEMPERATURE ON PEOPLE AND ANIMALS. WIND CHILL IS BASED ON THE RATE OF HEAT LOSS FROM EXPOSED SKIN. WEARING LAYERS OF CLOTHING WILL HELP RETAIN YOUR BODY HEAT AND COMBAT WIND CHILL. ONCE WIND CHILL TEMPERATURES DROP BELOW -20 DEGREES F, EXPOSED FLESH CAN FREEZE IN 30 MINUTES OR LESS, CAUSING FROST BITE.
WINTER STORMS ARE DECEPTIVE KILLERS BECAUSE MOST DEATHS ARE INDIRECTLY RELATED TO THE STORM. EXAMPLES ARE TRAFFIC ACCIDENTS DUE TO ICY ROADS, HEART ATTACKS WHILE SHOVELING SNOW, FIRES, AND CARBON MONOXIDE POISONING.
For updated forecasts for eastern North Carolina, visit the wnct.com Storm Team 9 weather page.
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