PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THU MAY 17 2018 MONTHLY FORECAST DISCUSSION VALID JUNE 2018 SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO NEGATIVE ONE-HALF DEGREE C OVER THE NORTHERN HAWAIIAN ISLANDS, AND ABOUT POSITIVE ONE-HALF TO ONE DEGREE C OVER THE SOUTHEASTERN ISLANDS. FOR JANUARY 2018 THROUGH THE END OF APRIL 2018, RAINFALL TOTAL ACCUMULATIONS WERE: - LIHUE AIRPORT 24.34 INCHES (177 PERCENT OF NORMAL) - HONOLULU AIRPORT 7.94 INCHES (114 PERCENT OF NORMAL) - KAHULUI AIRPORT 12.51 INCHES (143 PERCENT OF NORMAL) - HILO AIRPORT 54.26 INCHES (124 PERCENT OF NORMAL) THE NCEP CLIMATE FORECAST SYSTEM (CFS) AND OTHER CLIMATE MODELS RUN AS A PART OF THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) PREDICT ABOVE NORMAL SSTS AROUND THE SOUTHEASTERN HAWAIIAN ISLANDS FOR JUNE 2018. THIS ELEVATES THE CHANCES OF ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR KAHULUI AND HILO IN JUNE 2018. BELOW NORMAL TEMPERATURES ARE FAVORED FOR LIHUE WHERE SSTS ARE CURRENTLY BELOW NORMAL. MOST DYNAMICAL TOOLS ALSO FAVOR ABOVE NORMAL PRECIPITATION FOR THE SOUTHEASTERN ISLANDS (HILO AND KAHULUI) DURING JUNE 2018. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV HILO A60 75.4 0.4 A50 5.3 6.3 8.7 KAHULUI A50 78.0 0.5 A40 0.1 0.1 0.2 HONOLULU EC 80.3 0.4 EC 0.1 0.2 0.3 LIHUE B40 78.1 0.4 EC 1.1 1.3 1.6 SEASONAL FORECAST DISCUSSION VALID JJA 2018 - JJA 2019 REFER TO THE PROGNOSTIC DISCUSSION ON LONG-LEAD SEASONAL OUTLOOKS FOR THE CONUS AND ALASKA FOR A DISCUSSION OF THE FORECASTS OF EQUATORIAL PACIFIC SSTS, AND FOR THE GENERAL BACKGROUND FOR THE SEASONAL FORECAST, INCLUDING DETAILS ON THE CURRENT STATE OF THE ATMOSPHERE AND OCEAN. ENSO-NEUTRAL CONDITIONS CURRENTLY ARE PRESENT ACROSS THE EQUATORIAL PACIFIC OCEAN. EQUATORIAL SEA SURFACE TEMPERATURES (SSTS) ARE NEAR-TO-BELOW AVERAGE ACROSS THE EAST-CENTRAL AND EASTERN PACIFIC OCEAN, AND ABOVE AVERAGE IN THE WESTERN PACIFIC. POSITIVE SUBSURFACE TEMPERATURE ANOMALIES HAVE SHIFTED EASTWARD INTO THE EASTERN PACIFIC OCEAN,WHILE NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES HAVE WEAKENED IN THE FAR EASTERN PACIFIC OCEAN. CONVECTION WAS REMAINED SUPPRESSED NEAR AND EAST OF THE DATE LINE, WHILE LOW-LEVEL WIND ANOMALIES WERE NEAR AVERAGE OVER MOST OF THE TROPICAL PACIFIC OCEAN AND UPPER-LEVEL WINDS WERE ANOMALOUS WESTERLY OVER THE EASTERN PACIFIC. MOST MODELS INDICATE ENSO-NEUTRAL TO CONTINUE AT LEAST THROUGH THE NORTHERN HEMISPHERE SUMMER 2018, WITH THE POSSIBILITY OF EL NINO NEARING 50% BY NORTHERN HEMISPHERE WINTER 2018-19. ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HONOLULU AND LIHUE FROM JAS TO NDJ, 2018. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR HILO AND KAHULUI FROM JJA 2018 TO NDJ 2018 DUE TO PREDICTED ABOVE NORMAL SEA SURFACE TEMPERATURES ACROSS THE REGION. EQUAL CHANCES (EC) FOR ABOVE, NEAR, OR BELOW NORMAL TEMPERATURES ARE INDICATED AT ALL LOCATIONS FOR DJF 2019 AND BEYOND. DYNAMICAL TOOLS AND CONSTRUCTED ANALOG TOOL FAVOR ABOVE NORMAL PRECIPITATION FOR HAWAII FROM JJA TO ASO, 2018. THE STATISTICAL TOOLS (CANONICAL CORRELATION ANALYSIS, AND ENSO-OCN) PREDICT BELOW NORMAL PRECIPITATION DURING THE SUMMER. THEREFORE THE PROBABILITIES OF ABOVE NORMAL PRECIPITATION ARE LOWERED. SOME ENSO FORECAST MODELS PREDICT A WARM EVENT (EL NINO) BY THE NORTHERN HEMISPHERE WINTER 2018-19. IF CORRECT, HISTORICAL EL NINO COMPOSITES FAVOR INCREASED ODDS FOR DRY CONDITIONS FOR HAWAII IN WINTER, WHICH IS CONSISTENT WITH THE FORECAST FROM THE STATISTICAL TOOLS (CONSTRUCTED ANALOG, CANONICAL CORRELATION ANALYSIS, AND ENSO-OCN). THERE IS CONSIDERABLE UNCERTAINTY ACROSS THE HAWAIIAN ISLANDS IN THE PRECIPITATION FORECAST AMONG AVAILABLE FORECAST TOOLS FROM SON TO OND 2018, AND IN JFM AND LONGER LEADS, SO EQUAL CHANCES (EC) FOR ABOVE, NEAR, OR BELOW NORMAL PRECIPITATION ARE INDICATED. HILO TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV JJA 2018 A65 75.2 0.4 A50 19.4 27.2 31.4 JAS 2018 A60 76.1 0.4 A45 25.2 28.6 33.4 ASO 2018 A55 76.4 0.4 A40 26.1 28.8 33.3 SON 2018 A50 76.2 0.4 EC 24.3 30.2 40.8 OND 2018 A45 75.5 0.4 EC 28.3 34.5 42.0 NDJ 2018 A40 74.2 0.4 B40 26.4 36.6 43.0 DJF 2019 EC 72.8 0.4 B40 19.6 30.2 33.3 JFM 2019 EC 71.8 0.4 EC 22.0 32.0 44.5 FMA 2019 EC 71.7 0.4 EC 24.6 34.1 45.5 MAM 2019 EC 72.0 0.5 EC 22.5 28.4 34.0 AMJ 2019 EC 72.9 0.5 EC 21.4 23.7 29.0 MJJ 2019 EC 74.0 0.4 EC 20.2 27.5 29.1 JJA 2019 EC 75.2 0.4 EC 19.4 27.2 31.4 \N KAHULUI TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV JJA 2018 A65 77.7 0.4 A50 0.7 1.1 1.5 JAS 2018 A60 79.0 0.4 A45 0.8 1.1 1.6 ASO 2018 A55 79.4 0.4 A40 0.8 1.6 2.5 SON 2018 A50 79.1 0.4 EC 2.1 3.3 4.8 OND 2018 A45 77.8 0.4 EC 4.2 5.3 8.1 NDJ 2018 A40 75.9 0.4 B40 5.2 7.6 9.5 DJF 2019 EC 73.8 0.4 B40 4.6 6.9 8.7 JFM 2019 EC 72.5 0.4 EC 4.2 6.2 8.2 FMA 2019 EC 72.3 0.4 EC 3.2 4.1 6.4 MAM 2019 EC 73.0 0.4 EC 2.5 3.5 4.6 AMJ 2019 EC 74.3 0.5 EC 1.2 1.6 2.2 MJJ 2019 EC 76.0 0.5 EC 0.7 1.1 1.8 JJA 2019 EC 77.7 0.4 EC 0.7 1.1 1.5 \N HONOLULU TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV JJA 2018 EC 79.9 0.4 A50 0.7 0.8 1.3 JAS 2018 A55 81.3 0.4 A45 1.0 1.4 1.7 ASO 2018 A55 81.7 0.4 A40 1.6 2.4 3.1 SON 2018 A50 81.4 0.4 EC 2.5 4.0 5.6 OND 2018 A45 80.0 0.4 EC 4.4 6.4 8.5 NDJ 2018 A40 77.7 0.5 B40 3.9 5.6 8.8 DJF 2019 EC 75.3 0.5 B40 3.7 5.6 8.6 JFM 2019 EC 73.9 0.4 EC 2.1 4.6 7.8 FMA 2019 EC 73.8 0.4 EC 1.9 3.2 4.7 MAM 2019 EC 74.8 0.4 EC 1.8 2.6 3.0 AMJ 2019 EC 76.3 0.4 EC 1.2 1.6 1.8 MJJ 2019 EC 78.2 0.4 EC 0.8 1.4 1.6 JJA 2019 EC 79.9 0.4 EC 0.7 0.8 1.3 \N LIHUE TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV JJA 2018 EC 77.7 0.4 A50 4.4 5.3 6.9 JAS 2018 A55 79.0 0.3 A45 5.3 6.1 7.8 ASO 2018 A55 79.4 0.3 A40 6.2 7.9 8.4 SON 2018 A50 79.1 0.3 EC 9.2 10.0 11.2 OND 2018 A45 77.8 0.3 EC 9.2 11.7 15.6 NDJ 2018 A40 75.7 0.3 B40 8.6 12.1 16.9 DJF 2019 EC 73.6 0.4 B40 7.5 8.4 14.0 JFM 2019 EC 72.2 0.4 EC 6.5 8.8 13.8 FMA 2019 EC 72.1 0.5 EC 5.8 8.4 9.9 MAM 2019 EC 72.8 0.5 EC 5.3 6.6 8.0 AMJ 2019 EC 74.2 0.5 EC 4.7 5.5 6.0 MJJ 2019 EC 76.0 0.5 EC 4.9 5.4 5.9 JJA 2019 EC 77.7 0.4 EC 4.4 5.3 6.9 \NFORECASTER: LUKE HE 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 JUN 21, 2018. $$