Prognostic Discussion for Long-Lead Hawaiian Outlooks NWS Climate Prediction Center College Park MD 830AM EST Thu Jan 19 2023 MONTHLY FORECAST DISCUSSION VALID FEBRUARY 2023 Sea surface temperature (SST) anomalies from zero to positive one-half degree Celsius were observed over the Hawaiian islands (Kauai, Oahu, Maui and the Big Island) during the previous week. For January through December 2022, rainfall total accumulations were: - Lihue Airport 26.74 inches (74 percent of normal) - Honolulu Airport 12.15 inches (74 percent of normal) - Kahului Airport 6.69 inches (41 percent of normal) - Hilo Airport 93.85 inches (78 percent of normal) The NCEP Climate Forecast System (CFS) and other climate models of the North American Multi-Model Ensemble (NMME) predict above average SSTs around the Hawaiian Islands through February 2023. Dynamical ensembles and the Week 3-4 Outlook indicate large probabilities for above normal temperatures throughout Hawaii at the beginning of February. This supports likely above normal temperatures over the Hawaiian Islands in February 2023. Above normal precipitation is favored slightly for the Hawaiian Islands in February 2023, supported by most dynamical and statistical models and consistent with current La Niña conditions that are expected to transition to ENSO-neutral conditions during the next three months. Continued eastward propagation of the Madden-Julian Oscillation (MJO) from the Indian Ocean to the Maritime Continent favors increased precipitation at the start of the month. TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV Hilo A55 71.4 0.5 A45 5.0 8.4 11.1 Kahului A55 71.9 0.6 A45 0.9 1.1 1.8 Honolulu A55 73.3 0.5 A45 0.7 1.0 1.4 Lihue A55 71.7 0.6 A45 1.3 1.8 4.0 SEASONAL FORECAST DISCUSSION VALID FMA 2023 - FMA 2024 Refer to the prognostic discussion of the long-lead seasonal outlooks for the CONUS and Alaska for a description of the ENSO outlook and other climate conditions relevant to the seasonal outlook. La Niña conditions continue across the Pacific Ocean, with below average sea surface temperatures (SSTs) across most of the Pacific Ocean. However, a transition to ENSO-neutral conditions is considered imminent following dynamical and statistical model forecasts and the official ENSO outlook. Negative subsurface temperature anomalies near the surface weakened in the central and east-central Pacific Ocean, while positive subsurface temperature anomalies remained at depth from the western Pacific into the east-central Pacific Ocean. In the monthly average, low-level easterly wind anomalies and upper-level westerly wind anomalies were observed across most of the equatorial Pacific Ocean. Convection remained suppressed over the western and central tropical Pacific and enhanced over Indonesia. The tropical Pacific atmosphere and ocean remain consistent overall with La Niña conditions. La Niña is favored to continue only through the winter season (January-March, JFM) 2023, with a greater than 70 percent chance of transition to ENSO-neutral conditions in February-April (FMA) 2023. Enhanced probabilities for above normal temperatures are forecast for the Hawaiian Islands from FMA 2023 through summer (July-September, JAS) 2023, consistent with most dynamical model forecasts from the NMME and statistical forecasts. The forecast signal weakens at longer leads, therefore Equal Chances (EC) for above, near or below normal temperatures is indicated for Hawaii beginning in ASO 2023 and extending through longer leads. Enhanced probabilities for above normal precipitation are forecast over Hawaii from FMA 2023 to AMJ 2023 for southeastern islands and from FMA 2023 to MJJ 2023 for northwestern islands, consistent with most dynamical and statistical model forecasts. Due to considerable uncertainty in the precipitation forecasts from dynamical and statistical models, EC is indicated over the Hawaiian Islands beginning in MJJ 2023 for southeastern islands and beginning in JJA 2023 for northwestern islands. Hilo TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV FMA 2023 A60 71.7 0.4 A60 24.6 34.1 45.5 MAM 2023 A55 72.0 0.5 A50 22.5 28.4 34.0 AMJ 2023 A50 72.9 0.5 A40 21.4 23.7 29.0 MJJ 2023 A45 74.0 0.4 EC 20.2 27.5 29.1 JJA 2023 A40 75.2 0.4 EC 19.4 27.2 31.4 JAS 2023 A40 76.1 0.4 EC 25.2 28.6 33.4 ASO 2023 EC 76.4 0.4 EC 26.1 28.8 33.3 SON 2023 EC 76.2 0.4 EC 24.3 30.2 40.8 OND 2023 EC 75.5 0.4 EC 28.3 34.5 42.0 NDJ 2023 EC 74.2 0.4 EC 26.4 36.6 43.0 DJF 2024 EC 72.8 0.4 EC 19.6 30.2 33.3 JFM 2024 EC 71.8 0.4 EC 22.0 32.0 44.5 FMA 2024 EC 71.7 0.4 EC 24.6 34.1 45.5 Kahului TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV FMA 2023 A60 72.3 0.4 A60 3.2 4.1 6.4 MAM 2023 A55 73.0 0.4 A50 2.5 3.5 4.6 AMJ 2023 A50 74.3 0.5 A40 1.2 1.6 2.2 MJJ 2023 A45 76.0 0.5 EC 0.7 1.1 1.8 JJA 2023 A40 77.7 0.4 EC 0.7 1.1 1.5 JAS 2023 A40 79.0 0.4 EC 0.8 1.1 1.6 ASO 2023 EC 79.4 0.4 EC 0.8 1.6 2.5 SON 2023 EC 79.1 0.4 EC 2.1 3.3 4.8 OND 2023 EC 77.8 0.4 EC 4.2 5.3 8.1 NDJ 2023 EC 75.9 0.4 EC 5.2 7.6 9.5 DJF 2024 EC 73.8 0.4 EC 4.6 6.9 8.7 JFM 2024 EC 72.5 0.4 EC 4.2 6.2 8.2 FMA 2024 EC 72.3 0.4 EC 3.2 4.1 6.4 Honolulu TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV FMA 2023 A60 73.8 0.4 A60 1.9 3.2 4.7 MAM 2023 A55 74.8 0.4 A50 1.8 2.6 3.0 AMJ 2023 A55 76.3 0.4 A40 1.2 1.6 1.8 MJJ 2023 A45 78.2 0.4 A40 0.8 1.4 1.6 JJA 2023 A40 79.9 0.4 EC 0.7 0.8 1.3 JAS 2023 A40 81.3 0.4 EC 1.0 1.4 1.7 ASO 2023 EC 81.7 0.4 EC 1.6 2.4 3.1 SON 2023 EC 81.4 0.4 EC 2.5 4.0 5.6 OND 2023 EC 80.0 0.4 EC 4.4 6.4 8.5 NDJ 2023 EC 77.7 0.5 EC 3.9 5.6 8.8 DJF 2024 EC 75.3 0.5 EC 3.7 5.6 8.6 JFM 2024 EC 73.9 0.4 EC 2.1 4.6 7.8 FMA 2024 EC 73.8 0.4 EC 1.9 3.2 4.7 Lihue TEMPERATURE PRECIPITATION FCST AVE LIM FCST BLW MEDIAN ABV FMA 2023 A60 72.1 0.5 A60 5.8 8.4 9.9 MAM 2023 A55 72.8 0.5 A50 5.3 6.6 8.0 AMJ 2023 A55 74.2 0.5 A40 4.7 5.5 6.0 MJJ 2023 A45 76.0 0.5 A40 4.9 5.4 5.9 JJA 2023 A40 77.7 0.4 EC 4.4 5.3 6.9 JAS 2023 A40 79.0 0.3 EC 5.3 6.1 7.8 ASO 2023 EC 79.4 0.3 EC 6.2 7.9 8.4 SON 2023 EC 79.1 0.3 EC 9.2 10.0 11.2 OND 2023 EC 77.8 0.3 EC 9.2 11.7 15.6 NDJ 2023 EC 75.7 0.3 EC 8.6 12.1 16.9 DJF 2024 EC 73.6 0.4 EC 7.5 8.4 14.0 JFM 2024 EC 72.2 0.4 EC 6.5 8.8 13.8 FMA 2024 EC 72.1 0.5 EC 5.8 8.4 9.9 FORECASTER: Dan Collins Anomalies are based on the 1991-2020 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 Feb 16, 2023. $$