PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THU SEP 20 2012 MONTHLY FORECAST DISCUSSION VALID OCTOBER 2012 SST ANOMALIES NEAR HAWAII IN MID-SEPTEMBER ARE AROUND NEGATIVE ONE DEGREE C. FOR JANUARY 2012 THROUGH THE END OF AUGUST, RAINFALL TOTAL ACCUMULATIONS WERE: - LIHUE AIRPORT 35.13 INCHES (163 PERCENT OF NORMAL) - HONOLULU AIRPORT 7.76 INCHES (87 PERCENT OF NORMAL) - KAHULUI AIRPORT 5.27 INCHES (49 PERCENT OF NORMAL) - HILO AIRPORT 65.59 INCHES (82 PERCENT OF NORMAL) THERE IS A STRONG CONSENSUS AMONG CLIMATE MODELS RUN AS A PART OF THE NATIONAL MULTI-MODEL ENSEMBLE (NMME) THAT SSTS NEAR THE HAWAIIAN ISLANDS WILL REMAIN BELOW NORMAL THROUGH THE MONTH OF OCTOBER, ELEVATING CHANCES FOR BELOW NORMAL MEAN TEMPERATURES FOR HAWAII IN OCTOBER 2012. THE NCEP CFS VERSION 2 MODEL IS CONSISTENT WITH MOST OTHER NMME CLIMATE MODELS IN ITS PREDICTION OF CONDITIONS THAT FAVOR CONTINUED BELOW MEDIAN PRECIPITATION AMOUNTS FOR HAWAII IN OCTOBER 2012. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV HILO B45 75.7 0.5 B40 7.8 8.6 12.1 KAHULUI B40 78.2 0.4 B40 0.3 0.6 1.1 HONOLULU B40 80.2 0.5 B40 0.5 1.3 1.9 LIHUE B45 78.1 0.3 B40 2.5 3.3 4.2 SEASONAL FORECAST DISCUSSION VALID OND 2012 - OND 2013 REFER TO THE 90 DAY DISCUSSION FOR FORECASTS OF EQUATORIAL PACIFIC SST AND DETAILS OF THE GENERAL BACKGROUND TO THE FORECAST. CLIMATE INDICATORS CONTINUE TO SUGGEST THE ONSET OF WEAK EL NINO CONDITIONS IN THE NEXT MONTH OR TWO. SST ANOMALIES IN THE NINO 3.4 REGION OF THE PACIFIC ARE ALREADY ABOVE THE +0.5 DEGREE C THRESHOLD ASSOCIATED WITH EL NINO EVENTS. THE LATEST MODEL FORECASTS SHOW WEAKER SST ANOMALIES FOR THE EQUATORIAL PACIFIC OCEAN THAN THEY DID ONE MONTH AGO SUGGESTING THAT CONDITIONS WILL BE MARGINAL FOR THE DEVELOPMENT OF THE WIDESPREAD ATMOSPHERIC CIRCULATION PATTERNS NORMALLY ASSOCIATED WITH EL NINO. CURRENT ATMOSPHERIC OBSERVATIONS FROM THE EASTERN AND CENTRAL TROPICAL PACIFIC ARE MORE SUGGESTIVE OF NEUTRAL ENSO CONDITIONS, WITH WEAK AND SOMEWHAT DISORGANIZED ANOMALY PATTERNS. THE CONSENSUS OF DYNAMICAL AND STATISTICAL MODELS FAVOR SST ANOMALIES IN THE NINO 3.4 REGION REACHING A PEAK OF SOMEWHERE BETWEEN +.5 C AND +1.0 C BY NOVEMBER OR DECEMBER, AND THEN DECREASING AFTER THAT. THIS SUGGESTS THAT WEAK EL NINO CONDITIONS WILL BE IN STORE FOR THIS COOL SEASON. BASED ON RESULTS FROM HISTORICAL STUDIES ON THE EFFECTS OF WARM EPISODES - DRIER THAN NORMAL CONDITIONS ARE EXPECTED FOR HAWAII AND SOME U.S.-AFFILIATED ISLANDS DURING THE WINTER. BELOW NORMAL TEMPERATURES ARE FAVORED FOR HAWAII FROM OND TO DJF 2012-2013 ACCORDING TO A MAJORITY OF CLIMATE MODELS RUN AS PART OF THE NMME, EXTENDING TO JFM 2013 FOR THE SOUTHEASTERN ISLANDS. THE MAJORITY OF NMME MEMBERS FAVOR BELOW MEDIAN PRECIPITATION FOR HAWAII FROM OND 2012 THROUGH JFM 2013 FOR MOST LOCATIONS. EQUATORIAL PACIFIC SST ANOMALIES ARE EXPECTED TO WEAKEN EARLY IN 2013, LEAVING LITTLE PREDICTIVE SIGNAL FOR THE LONGER LEADS FOR HAWAII. FORECASTER: DAVE UNGER HILO TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2012 B50 75.5 0.4 B50 28.3 34.5 42.0 NDJ 2012 B45 74.2 0.4 B45 26.4 36.6 43.0 DJF 2013 B40 72.8 0.4 B40 19.6 30.2 33.3 JFM 2013 B40 71.8 0.4 B40 22.0 32.0 44.5 FMA 2013 EC 71.7 0.4 EC 24.6 34.1 45.5 MAM 2013 EC 72.0 0.5 EC 22.5 28.4 34.0 AMJ 2013 EC 72.9 0.5 EC 21.4 23.7 29.0 MJJ 2013 EC 74.0 0.4 EC 20.2 27.5 29.1 JJA 2013 EC 75.2 0.4 EC 19.4 27.2 31.4 JAS 2013 EC 76.1 0.4 EC 25.2 28.6 33.4 ASO 2013 EC 76.4 0.4 EC 26.1 28.8 33.3 SON 2013 EC 76.2 0.4 EC 24.3 30.2 40.8 OND 2013 EC 75.5 0.4 EC 28.3 34.5 42.0 KAHULUI TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2012 B45 77.8 0.4 B40 4.2 5.3 8.1 NDJ 2012 B40 75.9 0.4 B40 5.2 7.6 9.5 DJF 2013 B40 73.8 0.4 B40 4.6 6.9 8.7 JFM 2013 B40 72.5 0.4 B40 4.2 6.2 8.2 FMA 2013 EC 72.3 0.4 EC 3.2 4.1 6.4 MAM 2013 EC 73.0 0.4 EC 2.5 3.5 4.6 AMJ 2013 EC 74.3 0.5 EC 1.2 1.6 2.2 MJJ 2013 EC 76.0 0.5 EC 0.7 1.1 1.8 JJA 2013 EC 77.7 0.4 EC 0.7 1.1 1.5 JAS 2013 EC 79.0 0.4 EC 0.8 1.1 1.6 ASO 2013 EC 79.4 0.4 EC 0.8 1.6 2.5 SON 2013 EC 79.1 0.4 EC 2.1 3.3 4.8 OND 2013 EC 77.8 0.4 EC 4.2 5.3 8.1 HONOLULU TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2012 B40 80.0 0.4 B40 4.4 6.4 8.5 NDJ 2012 B40 77.7 0.5 B40 3.9 5.6 8.8 DJF 2013 B40 75.3 0.5 B40 3.7 5.6 8.6 JFM 2013 EC 73.9 0.4 B40 2.1 4.6 7.8 FMA 2013 EC 73.8 0.4 EC 1.9 3.2 4.7 MAM 2013 EC 74.8 0.4 EC 1.8 2.6 3.0 AMJ 2013 EC 76.3 0.4 EC 1.2 1.6 1.8 MJJ 2013 EC 78.2 0.4 EC 0.8 1.4 1.6 JJA 2013 EC 79.9 0.4 EC 0.7 0.8 1.3 JAS 2013 EC 81.3 0.4 EC 1.0 1.4 1.7 ASO 2013 EC 81.7 0.4 EC 1.6 2.4 3.1 SON 2013 EC 81.4 0.4 EC 2.5 4.0 5.6 OND 2013 EC 80.0 0.4 EC 4.4 6.4 8.5 LIHUE TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV OND 2012 B40 77.8 0.3 B40 9.2 11.7 15.6 NDJ 2012 B40 75.7 0.3 B40 8.6 12.1 16.9 DJF 2013 B40 73.6 0.4 B40 7.5 8.4 14.0 JFM 2013 EC 72.2 0.4 EC 6.5 8.8 13.8 FMA 2013 EC 72.1 0.5 EC 5.8 8.4 9.9 MAM 2013 EC 72.8 0.5 EC 5.3 6.6 8.0 AMJ 2013 EC 74.2 0.5 EC 4.7 5.5 6.0 MJJ 2013 EC 76.0 0.5 EC 4.9 5.4 5.9 JJA 2013 EC 77.7 0.4 EC 4.4 5.3 6.9 JAS 2013 EC 79.0 0.3 EC 5.3 6.1 7.8 ASO 2013 EC 79.4 0.3 EC 6.2 7.9 8.4 SON 2013 EC 79.1 0.3 EC 9.2 10.0 11.2 OND 2013 EC 77.8 0.3 EC 9.2 11.7 15.6 FORECASTER: ANOMALIES BASED ON 1981-2010 MEANS CLARIFICATION: EC INDICATES EQUAL CHANCES THAT THE CLIMATE WILL FALL INTO ANY ONE OF THE THREE RANGES OR CATEGORIES WHOSE BOUNDARIES ARE SPECIFIED IN THE TABLES ABOVE. A FORECAST SPECIFICATION OF EC MEANS THERE IS NO PARTICULAR TILT OF THE ODDS TOWARD ABOVE - NORMAL - OR BELOW NORMAL CONDITIONS IN THE OUTLOOK. FOR EXAMPLE -A37 MEANS A 37% CHANCE THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE ABOVE CLASS - B36 MEANS A 36% PROBABILITY THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE BELOW CLASS - AND N35 MEANS A 35% PROBABILITY THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE NEAR NORMAL CLASS. WHEN EC IS SPECIFIED THE PROBABILITY OF THE MOST LIKELY CATEGORY CANNOT BE PREDICTED. 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 THU OCT 18, 2012. $$