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NOUS41 KLWX 121839
PNSLWX
DCZ001-MDZ003>007-009>011-013-014-016>018-501-502-VAZ025>031-
036>040-042-050>057-501>504-WVZ050>053-055-501>506-130645-
DISTRICT OF COLUMBIA-WASHINGTON-FREDERICK MD-CARROLL-
NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE-
PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT-
EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA-
ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON-
ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER-
PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX-
ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA-
KING GEORGE-NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND-
EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY-
WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL-
WESTERN PENDLETON-EASTERN PENDLETON-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
139 PM EST WED DEC 12 2012

    *      *     *      *       *       *    **     *   *      *   *
*        *          WHITE CHRISTMAS STATISTICS  *         *      *
    *           *        *         *                 *       *


IT IS TIME AGAIN FOR THE CHRISTMAS STATISTICS FOR BALTIMORE AND 
WASHINGTON...AS COMPILED BY THE NATIONAL WEATHER SERVICE'S 
BALTIMORE/WASHINGTON FORECAST OFFICE.

WHAT ARE THE CHANCES FOR A WHITE CHRISTMAS? ...

WHAT IS TYPICAL CHRISTMAS WEATHER? ...

FIRST FOR WASHINGTON...THEN FOR BALTIMORE...


                         *** WASHINGTON DC ***

EXAMINATION OF CLIMATE RECORDS GOING BACK TO 1872 FOR CHRISTMASES IN 
WASHINGTON DC SHOW A TYPICAL CHRISTMAS DAY IS PARTLY CLOUDY WITH A 
FROSTY EARLY MORNING LOW OF 30 AND AN AFTERNOON HIGH OF 44. BUT THE 
YEAR-TO-YEAR WEATHER CAN VARY CONSIDERABLY.

COLDEST CHRISTMASES...

THE COLDEST WAS 1983. THE LOW TEMPERATURE WAS 3 DEGREES ABOVE ZERO. 
THAT DAY ALSO PRODUCED THE COLDEST HIGH TEMPERATURE FOR THE DAY...A 
FRIGID 14 DEGREES THAT AFTERNOON. THE FIVE COLDEST LOW TEMPERATURES 
WERE:

          1983 - 3  DEGREES 
          1872 - 5  DEGREES 
          1989 - 11 DEGREES           
          1980 - 12 DEGREES 
          1906 - 13 DEGREES 

WARMEST CHRISTMASES...

THE WARMEST CHRISTMAS DAY WAS A TOASTY 72 DEGREES IN 1964. THE 5 
WARMEST CHRISTMASES:

          1964 - 72 DEGREES           
          1982 - 70 DEGREES 
          1965 - 69 DEGREES           
          1932 - 68 DEGREES 
          1889 - 65 DEGREES 

RECENT PAST CHRISTMAS DAY WEATHER:

LAST YEAR...HIGH PRESSURE SAW TO IT THAT WE HAD SEASONABLE TEMPERATURES 
AND A FAIR AMOUNT OF SUN WITH JUST A FEW HIGH CLOUDS. REAGAN NATIONAL 
AIRPORT...THE OFFICIAL MEASUREMENT LOCATION FOR WASHINGTON...RECORDED 
AN EARLY MORNING LOW OF 34...RISING TO AN AFTERNOON HIGH OF 48 DEGREES.

      2011 -->  HI 48  LOW 34   MOSTLY SUNNY AND SEASONABLE 
      2010 -->  HI 36  LOW 32   CLOUDY/MORNING FLURRIES
      2009 -->  HI 47  LOW 29   SNOWMELT/CLOUDY/MID AFTERNOON-NIGHT RAIN
      2008 -->  HI 58  LOW 32   PARTLY SUNNY HIGH OCCURRED AT MIDNIGHT
      2007 -->  HI 52  LOW 37   PARTLY SUNNY AND MILD
      2006 -->  HI 50  LOW 37   CLOUDY WITH AFTERNOON AND NIGHT RAIN
      2005 -->  HI 44  LOW 30   CLOUDY WITH AFTERNOON RAIN
      2004 -->  HI 33  LOW 24   SUNNY AND COLD
      2003 -->  HI 42  LOW 31   MOSTLY SUNNY AND BLUSTERY
      2002 -->  HI 39  LOW 33   RAIN WITH SOME SNOW/SLEET
      2001 -->  HI 41  LOW 28   MOSTLY SUNNY AND COOL
      2000 -->  HI 28  LOW 19   SUNNY BREEZY AND COLD

FOR SNOW LOVERS...

SNOW FALLING ON CHRISTMAS DAY IS A RARITY IN WASHINGTON. OF THE PAST 
128 YEARS SINCE 1884 WHEN SNOWFALL HAS BEEN MEASURED IN WASHINGTON... 
ONLY 10 TIMES HAS THERE BEEN MEASURABLE SNOW THAT ACTUALLY FELL ON 
CHRISTMAS DAY. THAT AVERAGES TO ABOUT ONCE EVERY 12-13 YEARS...OR ABOUT 
8 PERCENT.

THE 6 HIGHEST SNOWFALLS OCCURRING IN WASHINGTON ON CHRISTMAS DAY...

    1... 1962 ... 5.4 INCHES
    2... 1909 ... 4.5 INCHES
    3... 1969 ... 4.3 INCHES
    4... 1902 ... 1.0 INCHES
    5... 1935 ... 0.6 INCHES
    6... 1892 ... 0.5 INCHES

IF YOU INTERPRET A WHITE CHRISTMAS AS EITHER MEASURABLE SNOWFALL THAT 
DAY OR HAVING SNOW ALREADY ON THE GROUND (A SNOW DEPTH OF AN INCH OR 
MORE)...THE ODDS OF A WHITE CHRISTMAS ARE SLIGHTLY BETTER. SINCE 
1888...NINETEEN TIMES MEASURABLE SNOW WAS ON THE GROUND ON CHRISTMAS 
DAY THAT EITHER FELL THAT DAY...OR WAS STILL ON THE GROUND FROM AN 
EARLIER SNOWFALL. THAT AVERAGES TO A WHITE CHRISTMAS ABOUT ONCE EVERY 
6-7 YEARS...OR A 15 PERCENT CHANCE.

IN THE PAST 20 YEARS...THERE HAVE BEEN ONLY TWO CHRISTMASES THAT HAD 
SNOWFALL...1993 AND 2002. BOTH YEARS FEATURED JUST A FRACTION OF AN 
INCH. FURTHERMORE...THERE WERE ONLY TWO YEARS IN THE PAST 40 THAT HAD 
AN INCH OR MORE OF SNOW ON THE GROUND ON CHRISTMAS. THEY WERE DURING 
THE VERY COLD DECEMBER OF 1989...WHEN NEARLY 2 INCHES OF SNOW WAS ON 
THE GROUND FROM PREVIOUS SNOWFALL THAT MONTH...AND MORE RECENTLY IN 2009 
WHEN 7 INCHES WAS STILL ON THE GROUND FROM THE FIRST OF OUR MAJOR 
SNOWSTORMS THAT RECORD SETTING WINTER. ALL 7 INCHES OF THAT SNOWPACK ON 
CHRISTMAS 2009 MELTED BY THE NEXT MORNING.

OF NOTE...18 YEARS AGO...IN 1993 IN A SPAN LASTING LESS THAN 30 
MINUTES IN THE EVENING...0.2 INCH SNOW FELL...WITH UPWARDS OF AN 
INCH FALLING IN THE WESTERN SUBURBS. THAT QUICK BURST OF SNOW ON 
CHRISTMAS NIGHT 1993 CAUSED SEVERE TRAVEL PROBLEMS. MUCH OF THE SNOW 
MELTED ON CONTACT WITH PAVED SURFACES AS TEMPERATURES WERE JUST 
ABOVE FREEZING AT THE TIME THE SNOW FELL. HOWEVER...AN ARCTIC COLD 
FRONT SWEPT IN JUST AFTER THE SNOW ENDED. ANY WATER REMAINING ON 
ROADS AND SIDEWALKS FROM MELTED SNOW QUICKLY FLASH FROZE INTO A THIN 
LAYER OF ICE...WHICH CAUSED GRIDLOCK AND TREACHEROUS TRAVEL THAT NIGHT.

PRECIPITATION OF ANY SORT (RAIN INCLUDED) IS MUCH EASIER TO COME BY 
OF COURSE. FIFTY-ONE CHRISTMASES HAVE HAD MEASURABLE PRECIPITATION. 
THAT TRANSLATES TO ABOUT A 36 PERCENT PROBABILITY OF MEASURABLE 
PRECIPITATION...OR ROUGHLY ONE IN EVERY THREE YEARS.


                         *** BALTIMORE MD ***

EXAMINATION OF WEATHER RECORDS GOING BACK TO 1872...SHOWS A TYPICAL 
CHRISTMAS DAY IS PARTLY CLOUDY WITH A FROSTY EARLY MORNING LOW OF 26
AND AN AFTERNOON HIGH OF 43. BUT THE YEAR-TO-YEAR WEATHER CAN VARY 
CONSIDERABLY.

COLDEST CHRISTMASES...

THE COLDEST...1983 WHEN THE TEMPERATURE HIT ZERO DEGREES. THAT DAY ALSO 
PRODUCED THE COLDEST HIGH TEMPERATURE FOR THE DAY...A FRIGID 12 DEGREES 
THAT AFTERNOON. THE FIVE COLDEST LOWS WERE:

          1983 - 0  DEGREES          
          1980 - 7  DEGREES 
          1989 - 7  DEGREES           
          1960 - 12 DEGREES 
          1998 - 13 DEGREES 

WARMEST CHRISTMASES...

THE WARMEST WAS A TOASTY 72 DEGREES IN 1964. THE 5 WARMEST CHRISTMASES:

          1964 - 72 DEGREES 
          1982 - 70 DEGREES 
          1932 - 67 DEGREES 
          1893 - 67 DEGREES 
          1889 - 67 DEGREES 

RECENT PAST CHRISTMAS DAY WEATHER:

LAST YEAR...HIGH PRESSURE SAW TO IT THAT WE HAD SEASONABLE TEMPERATURES 
AND A FAIR AMOUNT OF SUN WITH JUST A FEW MAINLY HIGH CLOUDS. THURGOOD 
MARSHALL BWI AIRPORT RECORDED AN EARLY MORNING LOW OF 24...RISING TO AN 
AFTERNOON HIGH OF 48 DEGREES.

DURING THE AFTERNOON.

      2011 -->  HI 48  LOW 24   MOSTLY SUNNY AND SEASONABLE
      2010 -->  HI 34  LOW 29   CLOUDY/LIGHT SNOW IN THE MORNING
      2009 -->  HI 42  LOW 19   SNOWMELT/CLOUDY/LATE AFTERNOON-NIGHT RAIN
      2008 -->  HI 59  LOW 32   PARTLY SUNNY HIGH OCCURRED AT MIDNIGHT       
      2007 -->  HI 50  LOW 30   PARTLY SUNNY AND MILD       
      2006 -->  HI 50  LOW 30   CLOUDY WITH AFTERNOON AND NIGHT RAIN       
      2005 -->  HI 42  LOW 24   CLOUDY WITH AFTERNOON RAIN       
      2004 -->  HI 31  LOW 17   SUNNY AND COLD
      2003 -->  HI 41  LOW 28   MOSTLY SUNNY AND BLUSTERY
      2002 -->  HI 38  LOW 32   RAIN WITH SOME SNOW/SLEET
      2001 -->  HI 40  LOW 23   PARTLY SUNNY AND COOL
      2000 -->  HI 27  LOW 17   SUNNY BREEZY AND COLD

FOR SNOW LOVERS...

SNOW FALLING ON CHRISTMAS DAY IS A RARITY IN BALTIMORE. IT LAST 
HAPPENED TEN YEARS AGO IN 2002 WHEN A GENERALLY RAINY CHRISTMAS 
MORNING CHANGED TO SNOW DURING THE LATE MORNING. ENOUGH FELL TO YIELD 
AN INCH OF SNOWFALL. HOWEVER...OF THE PAST 119 YEARS SINCE 1893 WHEN 
SNOWFALL HAS BEEN MEASURED IN BALTIMORE MD...ONLY TWELVE TIMES HAVE 
THERE BEEN MEASURABLE SNOW THAT FELL ON CHRISTMAS DAY. THAT AVERAGES TO 
ABOUT ONCE EVERY 10 YEARS...OR ABOUT 10 PERCENT.

THE 6 HIGHEST SNOWFALLS OCCURRING IN BALTIMORE ON CHRISTMAS DAY...

    1... 1909 ... 9.3 INCHES
    2... 1969 ... 6.1 INCHES
    3... 1902 ... 3.0 INCHES
    4... 1962 ... 2.9 INCHES
    5... 1935 ... 1.2 INCHES
    6... 2002 ... 1.0 INCHES

IF YOU INTERPRET A WHITE CHRISTMAS AS EITHER MEASURABLE SNOWFALL OR 
HAVING SNOW ALREADY ON THE GROUND (A SNOW DEPTH OF AN INCH OR MORE)... 
THE ODDS OF A WHITE CHRISTMAS IMPROVE. SINCE 1893...THERE HAVE BEEN 
TWENTY FOUR CHRISTMASES THAT MEASURABLE SNOW EITHER FELL THAT DAY...OR 
WAS ON THE GROUND ALREADY FROM A PREVIOUS STORM. THAT AVERAGES TO A 
WHITE CHRISTMAS ABOUT ONCE EVERY 5 YEARS...OR A 20 PERCENT CHANCE.

IN THE PAST 20 YEARS THERE HAVE BEEN ONLY TWO CHRISTMASES THAT HAD 
MEASURABLE SNOW FALL THAT DAY...1993 AND 2002. BOTH YEARS FEATURED AN 
INCH OR LESS. FURTHERMORE...THERE WAS ONLY THREE YEARS IN THE PAST 40 
THAT HAD MORE THAN AN INCH OF SNOW ON THE GROUND ON CHRISTMAS. THE MOST 
RECENT WAS IN 2009 WHEN 6 INCHES WAS STILL ON THE GROUND FROM THE FIRST 
OF OUR MAJOR SNOWSTORMS THAT RECORD SETTING WINTER. ALL 6 INCHES OF 
THAT SNOWPACK MELTED BY THE NEXT MORNING.

PRECIPITATION OF ANY SORT (RAIN INCLUDED) IS MUCH EASIER TO COME BY 
OF COURSE. FORTY-NINE CHRISTMASES HAVE HAD MEASURABLE PRECIPITATION. 
THAT TRANSLATES TO ABOUT 35 PERCENT PROBABILITY OF MEASURABLE
PRECIPITATION...OR ROUGHLY ONE THIRD.

HAPPY HOLIDAYS!!

$$
NWS BALTIMORE/WASHINGTON JK/CS/SZ