706
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@xxxxxxxx
OR
RICHARD AHLBERG
ASOS PLANNED PRODUCT IMPROVEMENT PROGRAM MANAGER
SILVER SPRING MD
PHONE 301-713-1975 X160
E-MAIL RICHARD.AHLBERG@xxxxxxxx
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
$$
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