PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THU APR 16 2015 MONTHLY FORECAST DISCUSSION VALID MAY 2015 SST ANOMALIES ARE CURRENTLY AROUND POSITIVE ONE-HALF TO ONE DEGREE C SURROUNDING THE HAWAIIAN ISLANDS. FROM FEBRUARY 2015 THROUGH THE END OF MARCH 2015, RAINFALL TOTAL ACCUMULATIONS WERE: - LIHUE AIRPORT 3.55 INCHES (31 PERCENT OF NORMAL) - HONOLULU AIRPORT 2.42 INCHES (38 PERCENT OF NORMAL) - KAHULUI AIRPORT 14.10 INCHES (196 PERCENT OF NORMAL) - HILO AIRPORT 17.01 INCHES (53 PERCENT OF NORMAL) THE CFS AND OTHER CLIMATE MODELS RUN AS A PART OF THE NATIONAL MULTI-MODEL ENSEMBLE (NMME) PREDICT NEAR- TO ABOVE-NORMAL SSTS SURROUNDING THE HAWAIIAN ISLANDS FOR MAY 2015. THIS ELEVATES THE CHANCES OF ABOVE-NORMAL MONTHLY MEAN AIR TEMPERATURES FOR THE HAWAIIAN ISLANDS. ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE INDICATED FOR HAWAII IN MAY 2015 BY DYNAMICAL MODEL FORECASTS. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV HILO A50 74.0 0.5 A40 4.1 7.4 8.7 KAHULUI A50 75.8 0.6 A40 0.2 0.5 0.8 HONOLULU A45 78.0 0.6 A40 0.2 0.4 0.8 LIHUE A45 75.8 0.6 A40 1.3 1.5 2.3 SEASONAL FORECAST DISCUSSION VALID MJJ 2015 - MJJ 2016 REFER TO THE 90-DAY DISCUSSION FOR FORECASTS OF EQUATORIAL PACIFIC SST AND DETAILS OF THE GENERAL BACKGROUND TO THE FORECAST. EL NINO CONDITIONS CURRENTLY ARE OBSERVED ACROSS THE EQUATORIAL PACIFIC OCEAN. POSITIVE EQUATORIAL SST ANOMALIES REMAIN ACROSS THE CENTRAL PACIFIC AND WERE OBSERVED OVER THE EASTERN PACIFIC, WITH NEAR AVERAGE SSTS IN THE WESTERN PACIFIC. POSITIVE SUBSURFACE ANOMALIES ARE OBSERVED ACROSS THE CENTRAL AND EASTERN PACIFIC, WHILE NEGATIVE ANOMALIES ARE PRESENT IN THE WESTERN PACIFIC. CONVECTION WAS ENHANCED OVER THE CENTRAL PACIFIC AROUND THE DATE LINE. LOW-LEVEL WESTERLY WIND ANOMALIES CONTINUED OVER THE CENTRAL EQUATORIAL PACIFIC. UPPER-LEVEL ANOMALOUS EASTERLY WINDS PERSISTED ACROSS THE CENTRAL PACIFIC. MOST STATISTICAL AND DYNAMICAL CLIMATE MODELS PREDICT THE CONTINUATION OF EL NINO CONDITIONS THROUGH AUTUMN 2015. THE OFFICIAL ENSO OUTLOOK SUGGESTS THAT THERE IS APPROXIMATELY A 70% CHANCE OF THE CONTINUATION OF EL NINO CONDITIONS THROUGH SUMMER 2015 AND APPROXIMATELY A 60% CHANCE OF CONTINUATION THROUGH AUTUMN 2015. EL NINO CONDITIONS IN AUTUMN HISTORICALLY HAVE PRECEDED EL NINO CONDITIONS IN THE FOLLOWING WINTER. NMME MODELS PREDICT A TENDENCY FOR ABOVE-NORMAL TEMPERATURES FOR HAWAII FROM MJJ TO SON 2015 DUE TO THE EXPECTATION OF ABOVE-NORMAL SSTS IN SURROUNDING WATERS. CORRELATION OF SURFACE AIR TEMPERATURE TO SST IN THE NINO 3.4 REGION INDICATES EL NINO CONDITIONS ARE ASSOCIATED WITH ABOVE-NORMAL TEMPERATURES INTO OND 2015 FOR THE SOUTHEASTERN HAWAIIAN ISLANDS. EQUAL CHANCES FOR ABOVE-, NEAR- AND BELOW-NORMAL SSTS ARE INDICATED IN THE NORTHWESTERN HAWAIIAN ISLANDS BEGINNING IN OND 2015 AND IN THE SOUTHEASTERN HAWAIIAN ISLANDS FOR NDJ 2015 AND THEREAFTER. NCEP AND NMME CLIMATE MODELS SHOW ABOVE-MEDIAN PRECIPITATION AMOUNTS ARE FAVORED FOR ALL OF HAWAII FROM MJJ TO ASO 2015. CORRELATION OF PRECIPITATION TO SST IN THE NINO 3.4 REGION INDICATES EL NINO CONDITIONS ARE ASSOCIATED WITH ABOVE-MEDIAN PRECIPITATION IN THE WARM SEASONS, FROM MJJ THROUGH ASO, AND BELOW-MEDIAN PRECIPITATION IN THE COLD SEASONS, FROM NDJ THROUGH FMA, FOR THE HAWAIIAN ISLANDS. EQUAL CHANCES FOR ABOVE-, NEAR- AND BELOW-MEDIAN PRECIPITATION ARE INDICATED AT ALL LOCATIONS FOR SON AND OND 2015 AND FOR MAM 2016 AND THEREAFTER. HILO TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV MJJ 2015 A55 74.0 0.4 A40 20.2 27.5 29.1 JJA 2015 A50 75.2 0.4 A45 19.4 27.2 31.4 JAS 2015 A50 76.1 0.4 A45 25.2 28.6 33.4 ASO 2015 A50 76.4 0.4 A45 26.1 28.8 33.3 SON 2015 A45 76.2 0.4 EC 24.3 30.2 40.8 OND 2015 A40 75.5 0.4 EC 28.3 34.5 42.0 NDJ 2015 EC 74.2 0.4 B40 26.4 36.6 43.0 DJF 2016 EC 72.8 0.4 B45 19.6 30.2 33.3 JFM 2016 EC 71.8 0.4 B45 22.0 32.0 44.5 FMA 2016 EC 71.7 0.4 B40 24.6 34.1 45.5 MAM 2016 EC 72.0 0.5 EC 22.5 28.4 34.0 AMJ 2016 EC 72.9 0.5 EC 21.4 23.7 29.0 MJJ 2016 EC 74.0 0.4 EC 20.2 27.5 29.1 KAHULUI TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV MJJ 2015 A55 76.0 0.5 A40 0.7 1.1 1.8 JJA 2015 A50 77.7 0.4 A45 0.7 1.1 1.5 JAS 2015 A50 79.0 0.4 A45 0.8 1.1 1.6 ASO 2015 A50 79.4 0.4 A45 0.8 1.6 2.5 SON 2015 A45 79.1 0.4 EC 2.1 3.3 4.8 OND 2015 A40 77.8 0.4 EC 4.2 5.3 8.1 NDJ 2015 EC 75.9 0.4 B40 5.2 7.6 9.5 DJF 2016 EC 73.8 0.4 B45 4.6 6.9 8.7 JFM 2016 EC 72.5 0.4 B45 4.2 6.2 8.2 FMA 2016 EC 72.3 0.4 B40 3.2 4.1 6.4 MAM 2016 EC 73.0 0.4 EC 2.5 3.5 4.6 AMJ 2016 EC 74.3 0.5 EC 1.2 1.6 2.2 MJJ 2016 EC 76.0 0.5 EC 0.7 1.1 1.8 HONOLULU TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV MJJ 2015 A45 78.2 0.4 A40 0.8 1.4 1.6 JJA 2015 A50 79.9 0.4 A40 0.7 0.8 1.3 JAS 2015 A50 81.3 0.4 A40 1.0 1.4 1.7 ASO 2015 A45 81.7 0.4 A40 1.6 2.4 3.1 SON 2015 A40 81.4 0.4 EC 2.5 4.0 5.6 OND 2015 EC 80.0 0.4 EC 4.4 6.4 8.5 NDJ 2015 EC 77.7 0.5 B40 3.9 5.6 8.8 DJF 2016 EC 75.3 0.5 B40 3.7 5.6 8.6 JFM 2016 EC 73.9 0.4 B40 2.1 4.6 7.8 FMA 2016 EC 73.8 0.4 B40 1.9 3.2 4.7 MAM 2016 EC 74.8 0.4 EC 1.8 2.6 3.0 AMJ 2016 EC 76.3 0.4 EC 1.2 1.6 1.8 MJJ 2016 EC 78.2 0.4 EC 0.8 1.4 1.6 LIHUE TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV MJJ 2015 A45 76.0 0.5 A40 4.9 5.4 5.9 JJA 2015 A50 77.7 0.4 A40 4.4 5.3 6.9 JAS 2015 A50 79.0 0.3 A40 5.3 6.1 7.8 ASO 2015 A45 79.4 0.3 A40 6.2 7.9 8.4 SON 2015 A40 79.1 0.3 EC 9.2 10.0 11.2 OND 2015 EC 77.8 0.3 EC 9.2 11.7 15.6 NDJ 2015 EC 75.7 0.3 B40 8.6 12.1 16.9 DJF 2016 EC 73.6 0.4 B40 7.5 8.4 14.0 JFM 2016 EC 72.2 0.4 B40 6.5 8.8 13.8 FMA 2016 EC 72.1 0.5 B40 5.8 8.4 9.9 MAM 2016 EC 72.8 0.5 EC 5.3 6.6 8.0 AMJ 2016 EC 74.2 0.5 EC 4.7 5.5 6.0 MJJ 2016 EC 76.0 0.5 EC 4.9 5.4 5.9 FORECASTER: DAN COLLINS 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 A40 MEANS A 40% CHANCE THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE ABOVE CLASS, B40 MEANS A 40% 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, ALL CATEGORIES ARE EQUALLY LIKELY. 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 MAY 21, 2015. $$