NOTE: The nws-changes mailing list is no longer active. The list archives are made available for historical reasons.
-------- Original Message --------968 NOUS41 KWBC 101546
PNSWSH SERVICE CHANGE NOTICE 08-56 AMENDED NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC1045 AM EST WED DEC 10 2008
TO: SUBSCRIBERS:
-FAMILY OF SERVICES
-NOAA WEATHER WIRE SERVICE
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
OTHER NWS PARTNERS...AND NWS EMPLOYEES
FROM: AHSHA N. TRIBBLE
CHIEF...CLIMATE SERVICES DIVISION
OFFICE OF CLIMATE...WATER AND WEATHER SERVICES
SUBJECT: AMENDED: EL NINO SOUTHERN OSCILLATION /ENSO/ ALERTS...AS NEEDED...IN THE ENSO DIAGNOSTIC DISCUSSION POSTPONED UNTIL FEBRUARY 5 2009.
REFER TO: SERVICE CHANGE NOTICE 08-56 SENT ON SEPTEMBER 24 2008
AMENDED TO POSTPONE EFFECTIVE DATE FOR THIS CHANGE FROM DECEMBER 11 2008 TO FEBRUARY 5 2009 FOR TECHNICAL REASONS.
STARTING ON THURSDAY FEBRUARY 5 2009...THE NWS CLIMATE PREDICTION CENTER /CPC/ WILL INCLUDE AN ENSO ALERT FOR AN EL NINO OR LA NINA...AS NEEDED...IN THE BEGINNING SECTION OF THE MONTHLY ENSO DIAGNOSTIC DISCUSSION. AN ENSO ALERT WILL BE A WATCH... ADVISORY...OR FINAL ADVISORY /I.E. END OF AN EL NINO OR LA NINA/. THE ENSO DIAGNOSTIC DISCUSSION HAS ALWAYS INDICATED THE EXPECTED OCCURRENCE /OR LACK OF OCCURRENCE/ OF EL NINO OR LA NINA FOR THE NEXT THREE MONTHS. WITH SIGNIFICANT IMPACTS IN VARIOUS AREAS OF THE UNITED STATES OFTEN ASSOCIATED WITH CLIMATE VARIABILITY PATTERNS RELATED TO EL NINO AND LA NINA...CPC WILL NOW USE AN ALERT TO HIGHLIGHT WHEN EL NINO OR LA NINA IS EXPECTED TO DEVELOP...CONTINUE OR END. 1. AN ENSO WATCH WILL BE ISSUED WHEN A TRANSITION TO EL NINO OR LA NINA CONDITIONS IS EXPECTED IN THE NEXT 3 MONTHS.
2. AN ENSO ADVISORY WILL BE ISSUED WHEN EL NINO OR LA NINA CONDITIONS ARE ALREADY OBSERVED AND EXPECTED TO CONTINUE. 3. AN ENSO FINAL ADVISORY WILL BE ISSUED WHEN EITHER EL NINO OR LA NINA CONDITIONS HAVE ENDED. CPC DEFINES EL NINO /OR LA NINA/ CONDITIONS AS EXISTING WHEN:A ONE-MONTH POSITIVE /NEGATIVE/ SST ANOMALY IN THE NINO 3.4 REGION OF 0.5C /-0.5C/ OR GREATER /LESS/ IS OBSERVED AND IS EXPECTED TO PERSIST FOR AT LEAST 3 CONSECUTIVE MONTHS AND AN ATMOSPHERIC RESPONSE TYPICALLY ASSOCIATED WITH EL NINO /LA NINA/ IS OBSERVED OVER THE EQUATORIAL PACIFIC REGION AS PER EL NINO/LA NINA DOCUMENTATION ON THE FOLLOWING CPC WEB PAGE: /USE LOWER CASE/
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/ANALYSIS_MONITORING/ENSOCYCLE/ENSO_CYCLE.SHTML CPC USUALLY ISSUES THE MONTHLY ENSO DIAGNOSTICS DISCUSSION ON THE THURSDAY FROM THE 5TH TO THE 11TH...AT AROUND 9:00 A.M. EASTERN LOCAL TIME. IF NECESSARY THE ISSUANCE DATE MAY BE CHANGED WITH ADVANCE NOTICE /E.G. DUE TO HOLIDAYS/. IT IS ISSUED UNDER THE FOLLOWING:
WMO HEADING - FXUS24 KWNC AWIPS ID - PMDENS ON THE INTERNET /LOWER CASE/ AT:
HTTP://WWW.CPC.NOAA.GOV/PRODUCTS/ANALYSIS_MONITORING/ ENSO_ADVISORY/THE WARNING TERM WILL NOT BE USED IN THE ENSO ALERT SYSTEM SINCE WARNINGS ALMOST ALWAYS HAVE A NET NEGATIVE CONNOTATION FOR IMPACTS FROM SHORT-TERM WEATHER EVENTS. SINCE ENSO EVENTS HAVE A MORE NEUTRAL NET EFFECT THROUGH BOTH POSITIVE AND NEGATIVE IMPACTS FROM ENSO RELATED CLIMATE VARIABILITY PATTERNS...AN ADVISORY IS MORE APPROPRIATE FOR ENSO ALERTS. ALL OTHER INFORMATION IN THE ENSO DIAGNOSTIC DISCUSSION WILL CONTINUE TO BE ISSUED. CPC WILL CONTINUE TO ADDRESS CURRENT OCEANIC AND ATMOSPHERIC CONDITIONS IN THE PACIFIC AND RELATED CLIMATE VARIABILITY PATTERNS INCLUDING:
-ANALYSIS OF CURRENT AND RECENT PATTERNS IN SURFACE AND SUBSURFACE WATER TEMPERATURE ANOMALIES IN THE TROPICAL PACIFIC -RELATED ANALYSES SUCH AS RAINFALL...OUTGOING LONG WAVE RADIATION...ETC. -INFLUENCING FACTORS SUCH AS MADDEN-JULIAN OSCILLATIONS ...KELVIN WAVES...ETC-STATISTICAL AND COUPLED MODEL PREDICTIONS. FOR ADDITIONAL INFORMATION ON ENSO ALERT POLICY AND THE ENSO DIAGNOSTIC DISCUSSION...CONTACT
MICHAEL S. HALPERT NWS CLIMATE PREDICTION CENTER - W/NP5 5200 AUTH RD CAMP SPRINGS MD 20746 301-763-8000 EXT 7535 NWS NATIONAL NOTICES ARE ONLINE AT /USE LOWERCASE/HTTP://WWW.WEATHER/GOV/OS/NOTIF.HTM
$$
nws-changes archives: