PUBLIC INFORMATION STATEMENT...PART 2 OF 9
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI

...THE NEW WIND CHILL INDEX...

...WISCONSIN WINTER AWARENESS WEEK IS NOVEMBER 7-11...

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STARTING WITH THE 2001-02 WINTER...FORECASTERS AT THE NATIONAL
WEATHER SERVICE /NWS/ STARTED USING A NEW WIND CHILL TEMPERATURE
INDEX. THIS NEW INDEX IS DESIGNED TO CALCULATE A MORE ACCURATE
READING OF HOW THE COLD AIR FEELS ON THE HUMAN SKIN.

BETWEEN 1945 AND 2001...THE UNITED STATES AND CANADA USED AN OLD
INDEX WHICH RELIED ON OBSERVED WINDS 33 FEET ABOVE THE GROUND...AND
FOCUSED ON HOW FAST THE COLD TEMPERATURES...COMBINED WITH WINDS...
MADE WATER FREEZE.

.......BASIC INFORMATION ON THE NEW WIND CHILL INDEX............
THE NEW INDEX ACCOUNTS FOR THE WIND EFFECTS AT FACE LEVEL...AND A
BETTER CALCULATION FOR BODY HEAT LOSS.

     -FOR EXAMPLE...UNDER THE OLD INDEX SYSTEM...AN AIR TEMPERATURE
      OF 20 DEGREES WITH A 15 MPH WIND...TRANSLATED INTO A READING
      OF FIVE DEGREES BELOW ZERO. THE NEW INDEX CALCULATION WOULD
      TRANSLATE THE SAME CONDITIONS TO SIX DEGREES ABOVE ZERO.

EXPOSURE TO COLD...BITING AIR FOR LONG PERIODS OF TIME IS DANGEROUS.
THE MAIN GOAL OF THE UPDATE WAS TO USE MODERN SCIENCE IN REVISING
THE INDEX SO THAT IT MORE ACCURATELY REPRESENTS THE IMPACT ON HUMANS.

..........WHAT THE NEW INDEX IS BASED ON..................
     - WIND SPEED CALCULATED AT THE AVERAGE HEIGHT OF THE HUMAN FACE
       A BOUT FIVE FEET /THE HUMAN FACE IS MOST OFTEN EXPOSED TO
       THE COLD/.
     - AN UPDATED HEAT TRANSFER THEORY WHICH FACTORS IN HEAT LOSS
       FROM THE BODY TO ITS SURROUNDINGS DURING COLD WINDY
       DAYS.
     - A CONSISTENT STANDARD FOR SKIN TISSUE RESISTANCE.
     - A LOWERED CALM WIND THRESHOLD FROM FOUR MILES PER HOUR TO
       THREE MILES PER HOUR.

..........RESEARCH FOR THE NEW WIND CHILL INDEX.............
THE NATIONAL WEATHER SERVICE...ACTING ON BEHALF OF THE U.S. OFFICE OF
THE FEDERAL COORDINATOR FOR METEOROLOGICAL SERVICES AND SUPPORTING
RESEARCH...LED A TEAM OF INTERNATIONAL SCIENTISTS WITH THE GOAL
OF CREATING AN INTERNATIONAL STANDARD WIND CHILL INDEX AMONG THE
METEOROLOGICAL COMMUNITY.

     -DURING THE SPRING OF 2001...THE SCIENTISTS CONDUCTED CLINICAL
      TRIALS AND THE RESULTS HELPED TO VERIFY AND IMPROVE THE
      ACCURACY OF THE NEW FORMULA.
     -THE NATIONAL WEATHER SERVICE ADJUSTED THE WIND CHILL ADVISORY
      AND WARNING CRITERIA...BASED ON THE NEW FORMULA.

.........WIND CHILL ADVISORY AND WARNING THRESHOLDS.........
     -ROUGHLY...THE NORTHERN HALF OF WISCONSIN WILL HAVE AN ADVISORY
      THRESHOLD OF -25 AND A WARNING THRESHOLD OF -35. HOWEVER...
      SOME OF THE NORTHWEST COUNTIES WILL HAVE AN ADVISORY
      THRESHOLD OF -25 AND A WARNING THRESHOLD OF -40.

     -ROUGHLY...THE SOUTHERN HALF OF WISCONSIN WILL HAVE AN
      ADVISORY THRESHOLD OF -20 AND A WARNING THRESHOLD OF -35.

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FOR MORE INFORMATION ON THE NEW WIND CHILL INDEX...AND TO FIND THE
NEW WIND CHILL CHART...VISIT...

     HTTP://WWW.NWS.NOAA.GOV/OM/WINTER
     HTTP://WWW.CRH.NOAA.GOV/MKX/WINTER_PAGE.PHP  /ALL LOWER CASE/