PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS CLIMATE PREDICTION CENTER NCEP NATIONAL WEATHER SERVICE WASHINGTON DC 3 PM EDT THURSDAY SEPTEMBER 19 2002 MONTHLY OUTLOOK DISCUSSION FOR OCTOBER 2002 . . . . . . . . WARM EVENT ENSO (EL NINO) CONDITIONS HAVE CONTINUED TO DEVELOP OVER THE EQUATORIAL PACIFIC OVER THE PAST SEVERAL MONTHS - WITH GREATEST SST ANOMALIES OF SLIGHTLY OVER TWO DEGREES C LOCATED NEAR 160W. SST ANOMALIES IN THE IMMEDIATE VICINITY OF HAWAII - WHICH HAVE COOLED SLIGHTLY IN THE PAST WEEK TO AS MUCH OS 0.5 DEGREE C BELOW NORMAL JUST EAST OF THE ISLANDS - ARE EXPECTED TO HAVE A MORE DIRECT IMPACT ON THE MONTHLY TEMPERATURE OUTLOOK FOR OCTOBER. THE PRINCIPAL STATISTICAL TOOLS ARE SHOWING A PREFERENCE FOR ABOVE NORMAL - ESPECIALLY AT HONOLULU WHICH HAS A KNOWN WARM TREND - PROBABLY DUE TO URBAN INFLUENCES. A BALANCE AMONG THESE WAS USED TO FORMULATE THE TEMPERATURE FORECAST. NONE OF THE TOOLS GAVE ANY INDICATIONS FOR PRECIPITATION. FCST AVE LIM FCST BLW MEDIAN ABV HILO N2 75.8 0.5 CL 8.1 9.6 10.5 KAHULUI A2 78.3 0.5 CL 0.4 0.6 1.0 HONOLULU A4 80.0 0.5 CL 0.3 1.4 1.9 LIHUE N2 78.1 0.4 CL 2.0 3.2 4.3 SEASONAL OUTLOOK DISCUSSION FOR OCT-NOV-DEC 2002 TO OCT-NOV-DEC 2003 REFER TO THE 90 DAY DISCUSSION FOR FORECASTS OF EQUATORIAL PACIFIC SST AND DETAILS OF THE GENERAL BACKGROUND TO THE FORECAST. THE CURRENT PACIFIC WARM EPISODE (EL NINO) IS PREDICTED TO CONTINUE AT LEAST INTO SPRING 2003 - AND WOULD PROBABLY HAVE ITS GREATEST EFFECTS ON THE SUBTROPICAL AND MIDDLE LATITUDE CIRCULATION DURING THE WINTER. DURING PAST EL NINO EPISODES TEMPERATURES DURING THE COLDER HALF OF THE YEAR HAVE TENDED TO BE BELOW NORMAL IN MOST OF HAWAII. THE URBAN-RELATED WARMING TREND AT HONOLULU WOULD TEND TO COUNTERACT THIS - HOWEVER - AND THE OCN TOOL WHICH PICKS UP DECADAL SCALE TENDS HAS THE MOST CONSISTENT INDICATIONS FOR WARMTH AT THAT STATION. CCA ALSO SHOWS WARMTH THERE AND AT KAHULUI DURING SOME OF THE EARLY LEADS. THE FORECASTS SHOWN IN THE TABLES BELOW REFLECT A CONSENSUS OF THESE FACTORS - WITH THE CURRENT SST ANOMALIES NEAR HAWAII INFLUENCING ONLY THE FORECAST FOR OND 2002. THERE WERE FEW SIGNIFICANT INDICATIONS FOR PRECIPITATION - EXCEPT A COUPLE OF WEAK HINTS FOR DRIER THAN NORMAL AT LIHUE. SOMETIMES THE EL NINO-FORCED SOUTHWARD-DISPLACED STRONG ALEUTIAN LOW WILL PUSH THE SUBTOPICAL RIDGE SOUTH TO OVER HAWAII - WEAKENING THE TRADE WINDS AND LOWERING PRECIPITATION AMOUNTS. CLARIFICATION: CL INDICATES CLIMATOLOGICAL PROBABILITIES - WHICH MEANS THAT NO PARTICULAR TILT OF THE ODDS TOWARD ABOVE - NEAR - OR BELOW NORMAL CONDITIONS IS FORECAST. FOR EXAMPLE - A4 MEANS A 4% HIGHER THAN NORMAL CHANCE THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE ABOVE CLASS - B3 MEANS A 3% HIGHER THAN NORMAL PROBABILITY THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE BELOW CLASS - AND N2 MEANS A 2% HIGHER THAN NORMAL PROBBILITY THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE NEAR NORMAL CLASS. HILO TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2002 N2 74.2 0.4 CL 26.1 33.1 41.3 NDJ 2002 CL 72.8 0.4 CL 25.5 32.9 41.7 DJF 2003 A2 72.0 0.4 CL 20.1 27.2 35.9 JFM 2003 CL 71.8 0.4 CL 23.9 30.9 39.4 FMA 2003 CL 72.1 0.4 CL 29.5 35.9 43.1 MAM 2003 CL 72.8 0.5 CL 28.3 34.9 42.6 AMJ 2003 CL 73.9 0.4 CL 22.0 26.8 32.2 MJJ 2003 CL 75.0 0.4 CL 19.1 23.1 27.8 JJA 2003 CL 75.9 0.4 CL 19.5 24.2 29.6 JAS 2003 CL 76.3 0.4 CL 22.2 27.1 32.7 ASO 2003 CL 76.2 0.4 CL 23.4 27.0 31.0 SON 2003 CL 75.5 0.4 CL 25.8 31.7 38.4 OND 2003 CL 74.2 0.4 CL 26.1 33.1 41.3 KAHULUI TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2002 A3 75.9 0.5 CL 4.2 5.7 7.6 NDJ 2002 A3 73.8 0.5 CL 5.7 7.8 10.4 DJF 2003 CL 72.5 0.5 CL 6.8 9.0 11.7 JFM 2003 B2 72.4 0.5 CL 6.0 8.1 10.6 FMA 2003 B4 73.2 0.5 CL 4.3 6.0 8.1 MAM 2003 B2 74.4 0.6 CL 2.9 4.2 5.8 AMJ 2003 CL 75.8 0.6 CL 1.0 1.8 3.1 MJJ 2003 CL 77.3 0.6 CL 0.7 1.1 1.5 JJA 2003 CL 78.6 0.5 CL 0.8 1.1 1.3 JAS 2003 CL 79.1 0.5 CL 0.9 1.2 1.5 ASO 2003 CL 78.9 0.5 CL 1.3 1.8 2.5 SON 2003 CL 77.8 0.5 CL 2.2 3.1 4.3 OND 2003 CL 75.9 0.5 CL 4.2 5.7 7.6 HONOLULU TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2002 A4 77.3 0.5 CL 4.5 6.2 8.4 NDJ 2002 A3 75.0 0.5 CL 4.1 6.1 8.7 DJF 2003 A2 73.5 0.4 CL 5.0 6.9 9.1 JFM 2003 CL 73.5 0.4 CL 4.1 5.8 8.0 FMA 2003 B2 74.5 0.4 CL 3.4 4.6 6.1 MAM 2003 B2 76.0 0.4 CL 2.4 3.2 4.3 AMJ 2003 CL 77.7 0.4 CL 1.2 1.8 2.6 MJJ 2003 A2 79.3 0.4 CL 1.0 1.4 2.0 JJA 2003 A3 80.7 0.4 CL 0.8 1.2 1.6 JAS 2003 A4 81.2 0.4 CL 1.1 1.5 2.0 ASO 2003 A4 81.0 0.5 CL 1.7 2.6 3.8 SON 2003 A3 79.6 0.5 CL 2.7 4.0 5.9 OND 2003 A2 77.3 0.5 CL 4.5 6.2 8.4 LIHUE TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2002 A2 75.6 0.3 CL 10.7 13.3 16.2 NDJ 2002 CL 73.6 0.3 CL 9.8 12.5 15.8 DJF 2003 B2 72.4 0.4 CL 8.6 11.4 14.7 JFM 2003 B4 72.4 0.4 B2 8.0 10.8 14.1 FMA 2003 B5 73.1 0.4 B2 7.5 9.6 12.0 MAM 2003 B3 74.4 0.4 CL 7.3 9.2 11.4 AMJ 2003 B2 75.9 0.4 CL 5.3 7.0 9.0 MJJ 2003 CL 77.5 0.4 CL 4.6 6.2 8.0 JJA 2003 CL 78.8 0.3 CL 4.6 5.6 6.6 JAS 2003 CL 79.3 0.3 CL 5.1 6.2 7.4 ASO 2003 CL 79.0 0.3 CL 6.3 8.0 10.0 SON 2003 CL 77.7 0.3 CL 9.1 10.9 12.9 OND 2003 CL 75.6 0.3 CL 10.7 13.3 16.2 FORECASTER: A. J. WAGNER NOTE - THESE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF THEIR VALID PERIODS. WITHIN ANY VALID PERIOD OBSERVATIONS AND SHORTER RANGE FORECASTS SHOULD BE CONSULTED. ALSO - THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCE OF THE NEW SET NEXT MONTH ON THURSDAY OCTOBER 17 2002. NNNN NNNN