PUBLIC INFORMATION STATEMENT   
   NATIONAL WEATHER SERVICE LITTLE ROCK AR   
   600 AM CST TUE NOV 17 2015   
      
   ...WINTER PRECIPITATION TYPES...   
      
   NOVEMBER 16TH THROUGH 20TH IS WINTER WEATHER AWARENESS WEEK IN ARKANSAS.   
   PEOPLE ARE ASKED TO TAKE SOME TIME TO PREPARE FOR  THE UPCOMING WINTER SEASON.   
      
   TODAYS TOPIC IS WINTER PRECIPITATION TYPES.   
      
   SNOW -- SNOW FORMS IN THE CLOUDS AND REMAINS AS SNOW ALL THE WAY TO THE   
   GROUND. IT MOST COMMONLY TAKES THE FORM OF SNOWFLAKES...WHICH ARE THE FAMILIAR   
   SIX-SIDED ICE CRYSTALS. IT MAY ALSO FALL IN THE FROM OF SNOW PELLETS OR SNOW   
   GRAINS.   
      
   SNOW FLURRIES ARE NORMALLY SEEN AS A FEW SNOWFLAKES FALLING... ALTHOUGH   
   VISIBILITIES CAN BE REDUCED AT TIMES. IN ARKANSAS...THE TERM SNOW FLURRIES IS   
   USED TO INDICATE THAT NO ACCUMULATION IS  EXPECTED.   
      
   SNOW SHOWERS IS A TERM NOT OFTEN USED IN ARKANSAS. IN THIS TYPE OF   
   PRECIPITATION...THE SNOW FALLS AT VARYING INTENSITIES...OFTEN  CHANGING   
   INTENSITIES OVER BRIEF PERIODS. ACCUMULATION MAY OCCUR... ESPECIALLY DURING   
   MODERATE TO HEAVY SNOW SHOWERS.   
      
   BLOWING SNOW REFERS TO SNOW THAT IS ALREADY ON THE GROUND AND IS  LIFTED INTO   
   THE AIR BY THE WIND.   
      
   IN ARKANSAS...HEAVIER SNOWS USUALLY OCCUR WHEN COLD AIR IS ALREADY IN PLACE   
   OVER THE STATE AND A STRONG UPPER LEVEL LOW  PRESSURE SYSTEM MOVES OUT OF THE   
   SOUTHWESTERN UNITED STATES. THE  LOW SERVES TO PULL MOIST AIR FROM THE GULF OF   
   MEXICO NORTHWARD INTO  THE COLD AIR. LIGHT SNOW OR SNOW FLURRIES CAN ALSO   
   OCCUR IN THE COLD  AIR THAT FOLLOWS THE PASSAGE OF AN ARCTIC COLD FRONT.   
      
   SLEET -- SLEET CONSISTS OF PELLETS OF ICE. IN FACT...FOR PEOPLE WHO HAVE   
   TROUBLE WITH THE DIFFERENCE BETWEEN SLEET AND FREEZING RAIN... IT MAY BE   
   EASIER TO ASSOCIATE SLEET WITH ITS TECHNICAL NAME...WHICH IS ICE PELLETS. FOR   
   SLEET TO FORM...SNOW BEGINS FALLING FROM THE CLOUDS BUT THEN GOES THROUGH A   
   LAYER OF ABOVE-FREEZING AIR THOUSANDS OF FEET ABOVE THE GROUND. THIS CAUSES   
   THE SNOW TO CHANGE TO RAIN.  THEN...THE RAIN GOES THROUGH A LAYER OF   
   BELOW-FREEZING AIR...USUALLY AT LEAST TWO TO THREE THOUSAND FEET THICK...AND   
   THE PRECIPITATION  TURNS INTO PELLETS OF ICE.   
      
   SLEET TYPICALLY OCCURS IN A FAIRLY NARROW BAND. THIS BAND USUALLY MOVES...BUT   
   AT TIMES MAY REMAIN NEARLY STATIONARY...RESULTING IN ACCUMULATIONS OF SLEET.   
      
   IN ARKANSAS...SLEET MOST COMMONLY OCCURS IN A NARROW BAND BETWEEN AN AREA OF   
   RAIN TO THE SOUTH AND AN AREA OF SNOW TO THE NORTH.   
      
   FREEZING RAIN -- THIS WEATHER PHENOMENON IS SOMETIMES CALLED GLAZE... BECAUSE   
   OF THE GLAZE OF ICE IT PUTS ON SURFACES AT THE GROUND. FREEZING RAIN NORMALLY   
   OCCURS WHEN PRECIPITATION FALLS FROM THE  CLOUDS AS SNOW...THEN GOES THROUGH   
   AN ABOVE-FREEZING LAYER...WHICH  TURNS THE PRECIPITATION TO RAIN. THEN...THE   
   RAIN REACHES THE GROUND  WHERE TEMPERATURES ARE BELOW FREEZING. THE RAIN THEN   
   FREEZES AS IT  HITS EXPOSED OBJECTS. IN THE WORST CASES...EVERYTHING BECOMES   
   COATED  WITH A LAYER OF ICE.   
      
   IN ARKANSAS...FREEZING RAIN COMMONLY OCCURS AS AN ARCTIC HIGH  PRESSURE SYSTEM   
   BEGINS TO MOVE AWAY FROM THE STATE. IN THIS  SITUATION...COLD AIR IS STILL   
   LINGERING AT THE GROUND...BUT WARMER  SOUTHERLY WINDS FROM THE GULF OF MEXICO   
   BEGIN BRINGING MOISTURE BACK  OVER THE TOP OF THE COLD AIR. SINCE THE AIR AT   
   THE GROUND HAS NOT  WARMED ABOVE FREEZING...THE RAIN THAT FALLS FREEZES ON THE   
   GROUND  AND OTHER OBJECTS. FREEZING RAIN...AND ITS COUSIN FREEZING DRIZZLE...   
   OFTEN DEVELOP DURING THE LATE NIGHT HOURS...CREATING ICY CONDITIONS  FOR   
   MORNING RUSH HOUR.   
      
   FREEZING FOG -- WHILE THIS IS NOT PRECIPITATION FALLING FROM THE  CLOUDS...IT   
   IS ANOTHER WINTER WEATHER HAZARD. FREEZING FOG TYPICALLY DEVELOPS ON   
   CLEAR...CALM NIGHTS WHEN TEMPERATURES ARE BELOW FREEZING. FOG FORMS AND   
   FREEZES...USUALLY ON BRIDGES...OVERPASSES...AND OTHER ELEVATED ROADWAYS. IT   
   CAN CREATE QUITE A SURPRISE FOR MOTORISTS...DUE TO THE PRESENCE OF CLEAR SKIES   
   OVERHEAD.   
      
   FROST -- FROST DESCRIBES THE FORMATION OF THIN ICE CRYSTALS ON THE GROUND OR   
   OTHER SURFACES IN THE FORM OF SCALES...NEEDLES... FEATHERS...OR FANS. FROST   
   FORMS WHEN WATER VAPOR IN THE AIR TURNS  DIRECTLY TO ICE CRYSTALS ON AN   
   OBJECT. THE TEMPERATURE OF THE OBJECT  MUST BE BELOW FREEZING FOR FROST TO   
   OCCUR. HOWEVER...FROST IS  SOMETIMES SEEN ON THE GROUND WHEN OFFICIAL   
   TEMPERATURES ARE REPORTED  TO BE ABOVE FREEZING. THIS IS BECAUSE THE OFFICIAL   
   TEMPERATURE IS  TAKEN ABOUT FIVE FEET ABOVE THE GROUND...WHERE THE AIR CAN BE   
   A FEW  DEGREES WARMER THAN THE TEMPERATURE AT GROUND LEVEL.   
      
   $$   
      
      
      
      
   --- GTMail 1.26    
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