638
NOUS41 KWBC 271328
PNSWSH
PUBLIC INFORMATION STATEMENT...SERVICE CHANGE NOTICE 01-19
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
930 AM EDT FRI APR 27 2001
TO: NATIONAL WEATHER SERVICE EMPLOYEES...NOAAPORT
SUBSCRIBERS... NOAA WEATHER WIRE SUBSCRIBERS...NWS
CUSTOMERS AND PARTNERS...NWS EMPLOYEES
FROM: ROBERT E. LIVEZEY
CHIEF...CLIMATE SERVICES DIVISION
SUBJECT: RESUMPTION OF NATIONAL EXCESSIVE HEAT OUTLOOK
PRODUCTS...EFFECTIVE MAY 1 2001
ON TUESDAY...MAY 1 2001...THE NATIONAL WEATHER SERVICE/S CLIMATE
PREDICTION CENTER /CPC/ WILL RESUME THE DAILY NATIONAL EXCESSIVE
HEAT OUTLOOKS. THE OUTLOOKS WILL BE ISSUED DAILY AROUND 400 PM
EASTERN LOCAL TIME. THE OUTLOOKS WILL EMPHASIZE DAILY MEAN HEAT
INDEX TEMPERATURES RATHER THAN DAILY MAXIMUM HEAT INDEX...
ALTHOUGH CPC ALSO WILL PROVIDE THE EXPECTED VALUE OF THE MAXIMUM
HEAT INDEX DURING THE 5- OR 7- DAY FORECAST PERIOD AT
APPROXIMATELY 200 LOCATIONS.
BECAUSE HEALTH RISKS VARY ENORMOUSLY FROM AREA TO AREA...CPC WILL
ISSUE FORECASTS OF THE PROBABILITY OF THE HEAT INDEX EXCEEDING
THREE DIFFERENT THRESHOLDS. THESE PROBABILITY FORECASTS WILL BE
OVERLAID ON ISOLINES /LINES OF EQUAL VALUES/ OF THE
CLIMATOLOGICAL NORMAL PROBABILITY. CPC CHOSE THE THRESHOLD HEAT
INDEX VALUES BASED ON WHEN CUMULATIVE EXPOSURE WOULD BE
LIKELY TO CAUSE SIGNIFICANT HEALTH RISKS FOR A NUMBER OF THE MOST
VULNERABLE CITIES.
IN ADDITION...BECAUSE VULNERABILITY INCREASES WITH DURATION OF
THE HEAT WAVE...RISKS FOR EXCEEDING THE LOWER THRESHOLDS ARE FOR
DURATIONS LONGER THAN ONE DAY. THESE PRODUCTS WILL CONSIST OF
MAPS OF THE PROBABILITY OF DAILY MEAN HEAT INDEX TEMPERATURE FOR
THRESHOLDS EQUAL TO OR GREATER THAN 85 DEGREES F...
90 DEGREES F...OR 95F FOR EACH OF THE 3-7... 6-10...AND 8-14 DAY
FORECAST PERIODS. THE FORECASTS WILL BE FOR DIFFERENT MINIMUM
NUMBERS OF DAYS WITHIN THE 5 OR 7 DAY PERIOD OF THE FORECAST -
NAMELY 3...2 AND 1 DAYS - RESPECTIVELY - WHEN THE THRESHOLDS ARE
EQUALED OR EXCEEDED.
MORE SPECIFICALLY...FOR THE 3-7...6-10...AND 8-14 DAY OUTLOOK
PERIODS...THE NEW PRODUCTS PREDICT THE PERCENT CHANCE OF EQUALING
OR EXCEEDING THE FOLLOWING CRITERIA:
A. DAILY AVERAGE HEAT INDEX EQUAL TO OR GREATER THAN 85F THREE
OR MORE DAYS IN THE FORECAST PERIOD
B. DAILY AVERAGE HEAT INDEX EQUAL TO OR GREATER THAN 90F TWO OR
MORE DAYS IN THE FORECAST PERIOD
C. DAILY AVERAGE HEAT INDEX EQUAL TO OR GREATER THAN 95F ONE OR
MORE DAYS IN THE FORECAST PERIOD
THE WMO HEADINGS AND AWIPS IDENTIFIERS FOR THE NINE CHARTS ARE AS
FOLLOWS:
AV. HEAT INDEX 3-7 DAY 6-10 DAY 8-14 DAY
CRITERIA A PTAM90 KWNC PTAS90 KWNC PTAT90 KWNC
/85F+ FOR 3+DAYS/ RBGHI1 RBGHI4 RBGHI7
CRITERIA B PTAM95 KWNC PTAS95 KWNC PTAT95 KWNC
/90F+ FOR 2+DAYS/ RBGHI2 RBGHI5 RBGHI8
CRITERIA C PTAM00 KWNC PTAS00 KWNC PTAT00 KWNC
/95F+ FOR 1+DAY/ RBGHI3 RBGHI6 RBGHI9
NOTE: THE NUMBERS WITHIN THE WMO HEADINGS DO NOT COINCIDE WITH
THE HEAT INDEX THRESHOLDS.
THESE NINE CHARTS WILL BE ISSUED OVER AWIPS...NOAAPORT...AND THE
CPC HOME PAGE /USE LOWER CASE/:
HTTP://WWW.CPC.NCEP.NOAA.GOV
IF YOU HAVE ANY QUESTIONS...EITHER SEND E-MAIL OVER THE INTERNET
TO THE PUBLIC LIAISON AT /USE LOWER CASE/:
HTTP://WWW.NCEP.NOAA.GOV/MAIL_LIAISON.SHTML
OR WRITE TO:
NOAA/NWS
CLIMATE PREDICTION CENTER
OPERATIONS BRANCH - W/NP53
WORLD WEATHER BUILDING
5200 AUTH ROAD
CAMP SPRINGS MD 20746-4304
THIS AND OTHER SERVICE CHANGE NOTIFICATION MESSAGES ARE ON THE
INTERNET AT /USE LOWER CASE/:
WWW.NWS.NOAA/GOV/OM/NOTIF.HTM
END
---------- End Forwarded Message ----------