PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD 830AM EDT THU JUL 19 2018 MONTHLY FORECAST DISCUSSION VALID AUGUST 2018 SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO POSITIVE 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 JUNE 2018, RAINFALL TOTAL ACCUMULATIONS WERE: - LIHUE AIRPORT 27.31 INCHES (157 PERCENT OF NORMAL) - HONOLULU AIRPORT 8.34 INCHES (107 PERCENT OF NORMAL) - KAHULUI AIRPORT 13.71 INCHES (141 PERCENT OF NORMAL) - HILO AIRPORT 74.13INCHES (125 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 AUGUST 2018. THIS ELEVATES THE CHANCES OF ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR HAWAII IN AUGUST 2018. MOST DYNAMICAL TOOLS ALSO FAVOR ABOVE NORMAL PRECIPITATION FOR THE HAWAIIAN ISLANDS DURING AUGUST 2018. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV HILO A65 76.6 0.4 A50 7.6 8.4 10.3 KAHULUI A60 79.8 0.4 A50 0.3 0.5 0.6 HONOLULU A60 82.1 0.4 A50 0.1 0.2 0.4 LIHUE A55 79.7 0.4 A50 1.4 1.8 2.5 SEASONAL FORECAST DISCUSSION VALID ASO 2018 - ASO 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-ABOVE AVERAGE ACROSS MOST OF THE PACIFIC OCEAN. POSITIVE SUBSURFACE TEMPERATURE ANOMALIES HAVE INTENSIFIED AND EXPANDED INTO THE FAR EASTERN PACIFIC OCEAN. CONVECTION REMAINED SUPPRESSED NEAR THE DATE LINE. ANOMALOUS LOW-LEVEL WESTERLY WINDS WERE EVIDENT OVER THE EAST-CENTRAL TROPICAL PACIFIC OCEAN, WHILE UPPER-LEVEL WINDS WERE NEAR AVERAGE OVER MOST OF THE TROPICAL PACIFIC OCEAN. MOST MODELS INDICATE ENSO-NEUTRAL TO CONTINUE AT LEAST THROUGH THE NORTHERN HEMISPHERE SUMMER 2018, WITH THE PROBABILITY OF EL NINO NEARING 65% DURING THE NORTHERN HEMISPHERE AUTUMN, INCREASING TO ABOUT 70% BY NORTHERN HEMISPHERE WINTER 2018-19. ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HAWAII FROM ASO 2018 TO JFM 2019 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 FMA 2019 AND BEYOND. DYNAMICAL TOOLS FAVOR ABOVE NORMAL PRECIPITATION FOR HAWAII FROM ASO TO SON 2018. MOST ENSO FORECAST MODELS PREDICT A WARM EVENT (EL NINO) BY THE NORTHERN HEMISPHERE FALL OR WINTER 2018-19. IF CORRECT, HISTORICAL EL NINO COMPOSITES FAVOR INCREASED ODDS FOR DRY CONDITIONS FOR HAWAII IN WINTER AND SPRING , 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 IN OND 2018, AND IN MJJ 2019 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 ASO 2018 A65 76.4 0.4 A50 26.1 28.8 33.3 SON 2018 A65 76.2 0.4 A40 24.3 30.2 40.8 OND 2018 A60 75.5 0.4 EC 28.3 34.5 42.0 NDJ 2018 A60 74.2 0.4 B55 26.4 36.6 43.0 DJF 2019 A50 72.8 0.4 B65 19.6 30.2 33.3 JFM 2019 A40 71.8 0.4 B65 22.0 32.0 44.5 FMA 2019 EC 71.7 0.4 B60 24.6 34.1 45.5 MAM 2019 EC 72.0 0.5 B50 22.5 28.4 34.0 AMJ 2019 EC 72.9 0.5 B40 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 JAS 2019 EC 76.1 0.4 EC 25.2 28.6 33.4 ASO 2019 EC 76.4 0.4 EC 26.1 28.8 33.3 KAHULUI TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV ASO 2018 A65 79.4 0.4 A50 0.8 1.6 2.5 SON 2018 A65 79.1 0.4 A40 2.1 3.3 4.8 OND 2018 A60 77.8 0.4 EC 4.2 5.3 8.1 NDJ 2018 A60 75.9 0.4 B55 5.2 7.6 9.5 DJF 2019 A50 73.8 0.4 B65 4.6 6.9 8.7 JFM 2019 A40 72.5 0.4 B65 4.2 6.2 8.2 FMA 2019 EC 72.3 0.4 B60 3.2 4.1 6.4 MAM 2019 EC 73.0 0.4 B50 2.5 3.5 4.6 AMJ 2019 EC 74.3 0.5 B40 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 JAS 2019 EC 79.0 0.4 EC 0.8 1.1 1.6 ASO 2019 EC 79.4 0.4 EC 0.8 1.6 2.5 HONOLULU TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV ASO 2018 A60 81.7 0.4 A50 1.6 2.4 3.1 SON 2018 A60 81.4 0.4 A40 2.5 4.0 5.6 OND 2018 A55 80.0 0.4 EC 4.4 6.4 8.5 NDJ 2018 A55 77.7 0.5 B55 3.9 5.6 8.8 DJF 2019 A45 75.3 0.5 B65 3.7 5.6 8.6 JFM 2019 A40 73.9 0.4 B65 2.1 4.6 7.8 FMA 2019 EC 73.8 0.4 B60 1.9 3.2 4.7 MAM 2019 EC 74.8 0.4 B50 1.8 2.6 3.0 AMJ 2019 EC 76.3 0.4 B40 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 JAS 2019 EC 81.3 0.4 EC 1.0 1.4 1.7 ASO 2019 EC 81.7 0.4 EC 1.6 2.4 3.1 LIHUE TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV ASO 2018 A55 79.4 0.3 A50 6.2 7.9 8.4 SON 2018 A55 79.1 0.3 A40 9.2 10.0 11.2 OND 2018 A50 77.8 0.3 EC 9.2 11.7 15.6 NDJ 2018 A50 75.7 0.3 B55 8.6 12.1 16.9 DJF 2019 A45 73.6 0.4 B65 7.5 8.4 14.0 JFM 2019 A40 72.2 0.4 B65 6.5 8.8 13.8 FMA 2019 EC 72.1 0.5 B60 5.8 8.4 9.9 MAM 2019 EC 72.8 0.5 B50 5.3 6.6 8.0 AMJ 2019 EC 74.2 0.5 B40 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 JAS 2019 EC 79.0 0.3 EC 5.3 6.1 7.8 ASO 2019 EC 79.4 0.3 EC 6.2 7.9 8.4 FORECASTER: LUKE HE ANOMALIES ARE BASED ON THE 1981-2010 MEANS. CLARIFICATION: EC INDICATED EQUAL CHANCES THAT THE PREDICTED PARAMETER WILL FALL INTO ANY ONE OF THE THREE CATEGORIES, WHOSE BOUNDARIES ARE SPECIFIC IN THE TABLES ABOVE. A FORECAST SPECIFICATION OF EC MEANS THERE IS NO PARTICULATE TILT OF THE ODDS TOWARD ABOVE NORMAL OR BELOW NORMAL CONDITIONS IN THE OUTLOOK. FOR EXAMPLE A40 MEANS A 40% CHANCE THAT THE AVERAGE TEMPERATURE OR TOTAL PRECIPITATION WILL BE IN THE ABOVE NORMAL CLASS, B40 MEANS A 40% CHANCE THAT THE AVERAGE TEMPERATURE OR TOTAL PRECIPITATION WILL BE IN THE BELOW NORMAL CLASS, AND N35 MEANS A 35% PROBABILITY THAT THE AVERAGE TEMPERATURE OR TOTAL 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 THE VALID PERIODS. WITHIN ANY VALID PERIOD, OBSERVATIONS AND SHORTER RANGE FORECASTS SHOULD BE CONSULTED. ALSO, THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCES OF THE NEW SET NET MONTH, ON THU AUG 16, 2018. $$