Prognostic Discussion for Long-Lead Hawaiian Outlooks NWS Climate Prediction Center College Park MD 830AM EDT Thu Oct 17 2019 MONTHLY FORECAST DISCUSSION VALID NOVEMBER 2019 Sea surface temperature (SST) anomalies are about positive one to two degrees Celsius surrounding the Hawaiian Islands during the previous week. For January 2019 through September 2019, rainfall total accumulations were: - Lihue Airport 20.99 inches (89 percent of normal) - Honolulu Airport 11.19 inches (117 percent of normal) - Kahului Airport 10.17 Inches (92 percent of normal) - Hilo Airport 65.55 Inches (73 percent of normal) The NCEP Climate Forecast System (CFS) and other climate models of the North American Multi-Model Ensemble (NMME) predict above normal SSTs around the Hawaiian Islands for November 2019. Model guidance from the NMME indicates anomalies of 1-2 degrees C above normal. This elevates the chances of above normal monthly mean air temperatures for Hawaii in November 2019. Most dynamical models predict above normal precipitation over the Hawaiian Islands during November 2019, consistent with the Canonical Correlation Analysis (CCA) and Optimal Climate Normals (OCN) forecast tools. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV Hilo A65 74.4 0.4 A45 8.7 11.4 17.1 Kahului A65 76.0 0.6 A45 1.2 1.8 2.6 Honolulu A65 77.8 0.6 A45 0.9 1.4 2.1 Lihue A65 75.8 0.5 A40 2.6 3.5 5.5 SEASONAL FORECAST DISCUSSION VALID NDJ 2019 - NDJ 2020 Refer to the prognostic discussion of the long-lead seasonal outlooks for the CONUS and Alaska for a discussion of the ENSO outlook and other climate conditions relevant to the seasonal outlook, 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 above average across the western and central Pacific Ocean and are below average in the eastern Pacific. Positive subsurface temperature anomalies have strengthened in the central Pacific and have expanded to 120 W, while negative subsurface temperature anomalies have also strengthened and shifted eastward to the eastern Pacific. Low-level westerly wind anomalies are observed across the western and central equatorial Pacific Ocean, and upper-level easterly wind anomalies prevailed over much of the Pacific. ENSO-neutral is likely to continue through the Northern Hemisphere autumn 2019 with probabilities about 85% and spring 2020 with probabilities exceeding 55%. Enhanced probabilities for above normal temperatures are indicated across the Hawaiian Islands in the outlook from NDJ 2019 to MAM 2020, due to persistent above normal sea surface temperatures predicted by the NMME dynamical models, and supported by statistical models including the CCA and OCN through AMJ 2020. The signal weakens at longer leads, therefore Equal Chances (EC) for above, near, or below normal temperatures are indicated for Hawaii beginning in MJJ 2020 and thereafter. Most dynamical models predict larger signals for above normal precipitation over the Hawaiian Islands during NDJ 2019 to MAM 2020, though some statistical tools are on the drier side. Increasing uncertainty in the tropical climate state in AMJ 2020 and longer leads, leads to an indication of equal chances (EC) for above, near, or below normal precipitation for Hawaii. Hilo TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV NDJ 2019 A65 74.2 0.4 A40 26.4 36.6 43.0 DJF 2020 A60 72.8 0.4 A40 19.6 30.2 33.3 JFM 2020 A55 71.8 0.4 A45 22.0 32.0 44.5 FMA 2020 A50 71.7 0.4 A45 24.6 34.1 45.5 MAM 2020 A45 72.0 0.5 A40 22.5 28.4 34.0 AMJ 2020 A40 72.9 0.5 EC 21.4 23.7 29.0 MJJ 2020 EC 74.0 0.4 EC 20.2 27.5 29.1 JJA 2020 EC 75.2 0.4 EC 19.4 27.2 31.4 JAS 2020 EC 76.1 0.4 EC 25.2 28.6 33.4 ASO 2020 EC 76.4 0.4 EC 26.1 28.8 33.3 SON 2020 EC 76.2 0.4 EC 24.3 30.2 40.8 OND 2020 EC 75.5 0.4 EC 28.3 34.5 42.0 NDJ 2020 EC 74.2 0.4 EC 26.4 36.6 43.0 Kahului TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV NDJ 2019 A65 75.9 0.4 A40 5.2 7.6 9.5 DJF 2020 A60 73.8 0.4 A40 4.6 6.9 8.7 JFM 2020 A55 72.5 0.4 A45 4.2 6.2 8.2 FMA 2020 A50 72.3 0.4 A45 3.2 4.1 6.4 MAM 2020 A45 73.0 0.4 A40 2.5 3.5 4.6 AMJ 2020 A40 74.3 0.5 EC 1.2 1.6 2.2 MJJ 2020 EC 76.0 0.5 EC 0.7 1.1 1.8 JJA 2020 EC 77.7 0.4 EC 0.7 1.1 1.5 JAS 2020 EC 79.0 0.4 EC 0.8 1.1 1.6 ASO 2020 EC 79.4 0.4 EC 0.8 1.6 2.5 SON 2020 EC 79.1 0.4 EC 2.1 3.3 4.8 OND 2020 EC 77.8 0.4 EC 4.2 5.3 8.1 NDJ 2020 EC 75.9 0.4 EC 5.2 7.6 9.5 Honolulu TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV NDJ 2019 A65 77.7 0.5 A40 3.9 5.6 8.8 DJF 2020 A60 75.3 0.5 A40 3.7 5.6 8.6 JFM 2020 A50 73.9 0.4 A45 2.1 4.6 7.8 FMA 2020 A45 73.8 0.4 A45 1.9 3.2 4.7 MAM 2020 A40 74.8 0.4 A40 1.8 2.6 3.0 AMJ 2020 A40 76.3 0.4 EC 1.2 1.6 1.8 MJJ 2020 EC 78.2 0.4 EC 0.8 1.4 1.6 JJA 2020 EC 79.9 0.4 EC 0.7 0.8 1.3 JAS 2020 EC 81.3 0.4 EC 1.0 1.4 1.7 ASO 2020 EC 81.7 0.4 EC 1.6 2.4 3.1 SON 2020 EC 81.4 0.4 EC 2.5 4.0 5.6 OND 2020 EC 80.0 0.4 EC 4.4 6.4 8.5 NDJ 2020 EC 77.7 0.5 EC 3.9 5.6 8.8 Lihue TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV NDJ 2019 A65 75.7 0.3 A40 8.6 12.1 16.9 DJF 2020 A60 73.6 0.4 A40 7.5 8.4 14.0 JFM 2020 A50 72.2 0.4 A45 6.5 8.8 13.8 FMA 2020 A45 72.1 0.5 A45 5.8 8.4 9.9 MAM 2020 A40 72.8 0.5 A40 5.3 6.6 8.0 AMJ 2020 A40 74.2 0.5 EC 4.7 5.5 6.0 MJJ 2020 EC 76.0 0.5 EC 4.9 5.4 5.9 JJA 2020 EC 77.7 0.4 EC 4.4 5.3 6.9 JAS 2020 EC 79.0 0.3 EC 5.3 6.1 7.8 ASO 2020 EC 79.4 0.3 EC 6.2 7.9 8.4 SON 2020 EC 79.1 0.3 EC 9.2 10.0 11.2 OND 2020 EC 77.8 0.3 EC 9.2 11.7 15.6 NDJ 2020 EC 75.7 0.3 EC 8.6 12.1 16.9 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 Nov 21, 2019. $$