NOUS41 KWBC 191841 PNSWSH PUBLIC INFO. STATEMENT...TECHNICAL IMPLEMENTATION NOTICE 03-15 NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC 140 PM EST WED MAR 19 2003 TO FAMILY OF SERVICES /FOS/ SUBSCRIBERS...NOAA WEATHER WIRE SERVICE /NWWS/ SUBSCRIBERS...EMERGENCY MANAGERS WEATHER INFORMATION NETWORK /EMWIN/ SUBSCRIBERS... OTHER NATIONAL WEATHER SERVICE /NWS/ CUSTOMERS OF AVIATION DATA AND FORECASTS...NWS EMPLOYEES FROM RAINER DOMBROWSKY CHIEF...OBSERVING SERVICES DIVISION SUBJECT AUTOMATED SURFACE OBSERVING SYSTEM WIND SENSOR REPLACEMENT REFER TO TECHNICAL IMPLEMENTATION NOTICE /TIN/ 02-30...DATED OCTOBER 25 2002 THE FOLLOWING CHANGES HAVE NO DIRECT IMPACT ON NOAA WEATHER WIRE SERVICE SUBSCRIBERS. THE AUTOMATED SURFACE OBSERVING SYSTEM /ASOS/ PRODUCT IMPROVEMENT PROGRAM WILL SOON DEPLOY A REPLACEMENT WIND SENSOR. THE NEW SENSOR WILL REPORT WIND INFORMATION USING THE 3-SECOND WORLD METEOROLOGICAL ORGANIZATION /WMO/ GUST STANDARD. THE CURRENT ASOS WIND SENSOR /BELFORT 2000 / USES ROTATING CUPS TO MEASURE WIND SPEED AND A VANE TO MEASURE WIND DIRECTION. OVER A 2-MINUTE PERIOD...ASOS USES TWENTY-FOUR 5-SECOND AVERAGES TO DETERMINE THE 2-MINUTE AVERAGE WIND SPEED AND DIRECTION. EVERY MINUTE ASOS STORES THE HIGHEST 5-SECOND AVERAGE SPEED FOR THE PAST MINUTE... ALONG WITH ITS DIRECTION... IN THE 12-HOUR ARCHIVE FOR ADDITIONAL PROCESSING. THIS HIGHEST SPEED VALUE IS USED TO DETERMINE IF A GUST AND/OR A PEAK WIND REMARK WILL BE REPORTED. THE NEW ASOS WIND SENSOR /VAISALA 425NWS / IS A SONIC ANEMOMETER. IT HAS NO MOVING PARTS AND WILL OPERATE BETTER IN WINTER WEATHER CONDITIONS. AS WITH THE BELFORT SENSOR...OVER A 2-MINUTE PERIOD...ASOS USES TWENTY-FOUR 5-SECOND AVERAGES TO DETERMINE THE 2-MINUTE AVERAGE WIND SPEED AND DIRECTION. BUT THE HIGHEST 3-SECOND RUNNING AVERAGE SPEED IS STORED FOR GUST AND PEAK WIND PROCESSING. WHILE THERE WILL BE LITTLE DIFFERENCE IN 2-MINUTE AVERAGE WIND SPEED AND DIRECTION REPORTING...THE CHANGES IN GUST AND PEAK WIND REPORTING MAY BE SIGNIFICANT. WE CAN EXPECT TO SEE MORE GUSTS AND PEAK WINDS REPORTED WITH THE NEW SENSOR. THE MASS OF THE MOVING PARTS IN EXISTING SENSORS LIMITS RESPONSIVENESS. THE NEW SENSOR WILL BE MORE RESPONSIVE TO SHORT TERM GUSTS. THE LAST ACTIVITY PRIOR TO IMPLEMENTATION AT 313 NWS AND 570 FAA SPONSORED SITES IS A 20 SITE OPERATIONAL ACCEPTANCE TEST /OAT/. THE OAT BEGAN IN MID-SEPTEMBER OF 2002. EIGHTEEN /18/ OF THE 20 OAT SITES ARE CONFIGURED WITH DUAL SENSORS...BOTH THE EXISTING AND NEW SENSOR. THE EXISTING SENSOR IS BEING USED FOR THE OFFICIAL OBSERVATION AT LOCATIONS WHERE DUAL SENSORS ARE INSTALLED. DATA FROM THE NEW SENSOR OUTPUT IS BEING ARCHIVED FOR ANALYSIS. WHEN THE ANALYSIS VALIDATES THE NEW SENSOR PERFORMANCE...THE PROCESSING WILL BE CHANGED TO USE THE NEW SENSOR FOR THE OFFICIAL OBSERVATION AND THE NEW SENSORS WILL BE INSTALLED AT THE REMAINING 2 SINGLE SENSOR OAT SITES. BELFORT SENSOR DATA WILL CONTINUE TO BE ARCHIVED AT THE DUAL SENSOR SITES FOR FURTHER ANALYSIS. THIS CHANGE IN THE USE OF SENSORS IS EXPECTED TO OCCUR IN APRIL 2003. FOLLOWING A SUCCESSFUL OAT...FULL SCALE DEPLOYMENT OF THE NEW SENSOR WILL BEGIN IN JUNE OF 2003 AND EXTEND THROUGH SEPTEMBER 2005. OAT LOCATIONS SID STATION NAME CONFIGURATION DEPLOYMENT DATE BRW BARROW AK DUAL JANUARY 2003 TKA TALKEETNA, AK DUAL JANUARY 2003 KTN KETCHICAN AK DUAL JANUARY 2003 SIT SITKA AK DUAL JANUARY 2003 CMX HANCOCK MI DUAL NOVEMBER 2002 GFK GRAND FORKS ND DUAL OCTOBER 2002 TOP TOPEKA KS DUAL OCTOBER 2002 BFF SCOTTSBLUFF NE DUAL MARCH 2003 HUF TERRA HAUTE IN DUAL JANUARY 2003 OSH OSHKOSH WI DUAL NOVEMBER 2002 ARR CHICAGO/AURORA IL DUAL DECEMBER 2002 FTW FORT WORTH TX DUAL FEBRUARY 2003 NEW NEW ORLEANS LA DUAL JANUARY 2003 LLJ CHALLIS ID DUAL NOVEMBER 2003 UAO AURORA OR DUAL JANUARY 2003 BLU BLUE CANYON CA DUAL OCTOBER 2003 BTV BURLINGTON VT DUAL SEPTEMBER 2003 CAR CARIBOU ME DUAL SEPTEMBER 2003 ITO HILO HI SINGLE APRIL 2003 SFO SAN FRANCISCO CA SINGLE APRIL 2003 IF YOU HAVE ANY QUESTIONS ABOUT THIS CHANGE...PLEASE CONTACT ONE OF THE FOLLOWING INDIVIDUALS AT NWS HEADQUARTERS TIMOTHY ROSS SURFACE OBSERVATIONS PROGRAM MANAGER SILVER SPRING MD PHONE 301-713-1792 X114 E-MAIL TIM.ROSS@NOAA.GOV OR RICHARD AHLBERG ASOS PLANNED PRODUCT IMPROVEMENT PROGRAM MANAGER SILVER SPRING MD PHONE 301-713-1975 X160 E-MAIL RICHARD.AHLBERG@NOAA.GOV THIS AND OTHER NWS TECHNICAL IMPLEMENTATION NOTICES ARE AVAILABLE ON THE INTERNET AT /USE LOWER CASE LETTERS/ http://www.nws.noaa.gov/om/notif.htm $$ NNNN