678  
FXHW40 KWBC 211331  
PMDHCO  
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
830AM EST THU NOV 21 2024  
 
MONTHLY FORECAST DISCUSSION VALID DECEMBER 2024  
 
SEA-SURFACE TEMPERATURES (SSTS) SURROUNDING THE HAWAIIAN ISLANDS HAVE BEEN  
SLIGHTLY ABOVE AVERAGE DURING THE PAST FEW WEEKS.  
 
FROM JANUARY THROUGH OCTOBER 2024, RAINFALL TOTAL ACCUMULATIONS WERE:  
 
LIHUE AIRPORT 24.79 INCHES (90 PERCENT OF AVERAGE)  
 
HONOLULU AIRPORT 10.28 INCHES (86 PERCENT OF AVERAGE)  
 
KAHULUI AIRPORT 11.26 INCHES (97 PERCENT OF AVERAGE)  
 
HILO AIRPORT 83.14 INCHES (89 PERCENT OF AVERAGE)  
 
MOST CLIMATE MODELS OF THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE  
INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME OR C3S) FAVOR NEAR NORMAL SSTS AROUND  
THE HAWAIIAN ISLANDS IN DECEMBER 2024. A FEW SOLUTIONS LEAN TOWARDS ABOVE  
NORMAL SSTS, ESPECIALLY FOR KAUAI, WHILE ONLY THE NCEP CLIMATE FORECAST SYSTEM  
(CFSV2) FAVORS BELOW NORMAL SSTS FOR THIS PERIOD. BASED PRIMARILY ON THESE SST  
PREDICTIONS, EQUAL CHANCES (EC) OF BELOW, NEAR, AND ABOVE NORMAL TEMPERATURES  
ARE FAVORED FOR THE BIG ISLAND, MAUI, AND OAHU IN DECEMBER, AND A SLIGHT TILT  
TOWARDS ABOVE NORMAL TEMPERATURES IS FAVORED FOR KAUAI. FOR THE DECEMBER 2024  
PRECIPITATION OUTLOOK, THE C3S GENERALLY FAVORS NEAR NORMAL PRECIPITATION WITH  
TWO CONSTITUENT MODELS LEANING TOWARDS RELATIVELY WET CONDITIONS (METEO-FRANCE  
AND ECMWF), TWO MODELS SUPPORTING RELATIVELY DRY CONDITIONS (DWD AND CMCC), AND  
TWO FAVORING MIXED CONDITIONS (CFSV2 AND UKMO). THE NMME INPUTS DEPICTED MIXED  
RESULTS AT BEST. THEREFORE, EC APPEARS TO BE THE BEST BET FOR THE DECEMBER 2024  
PRECIPITATION OUTLOOK. THESE WEAK TEMPERATURE AND PRECIPITATION SIGNALS ARE TO  
BE EXPECTED GIVEN THE WEAK ENSO FORCING CURRENTLY ONGOING IN THE PACIFIC (SEE  
BELOW).  
 
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
HILO EC 72.5 0.4 EC 6.8 10.2 13.6  
KAHULUI EC 73.5 0.5 EC 1.9 2.7 3.4  
HONOLULU EC 74.9 0.6 EC 0.8 1.3 3.8  
LIHUE A40 73.3 0.5 EC 1.8 3.2 5.5  
 
SEASONAL FORECAST DISCUSSION VALID DJF 2024 - DJF 2025  
 
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. ENSO-NEUTRAL CONDITIONS CONTINUE  
TO BE OBSERVED OVER THE PACIFIC OCEAN. EQUATORIAL SEA SURFACE TEMPERATURES ARE  
NEAR-TO-BELOW-AVERAGE IN THE CENTRAL AND EASTERN PACIFIC OCEAN. NEGATIVE  
SUBSURFACE TEMPERATURE ANOMALIES REMAIN AT DEPTH IN THE CENTRAL AND EASTERN  
PACIFIC, WITH POSITIVE SUBSURFACE TEMPERATURE ANOMALIES CONTINUING OVER THE  
WESTERN PACIFIC. A RELATIVELY SMALL AREA OF LOW-LEVEL EASTERLY WIND ANOMALIES  
WAS OBSERVED IN THE EAST-CENTRAL EQUATORIAL PACIFIC OCEAN, WHILE UPPER-LEVEL  
WIND ANOMALIES WERE NEAR AVERAGE. SUPPRESSED CONVECTION WAS OBSERVED OVER THE  
VICINITY OF THE DATE LINE AND EQUATOR, WHILE NEAR TO SLIGHTLY ENHANCED  
CONVECTION WAS NOTED ACROSS EASTERN INDONESIA. COLLECTIVELY, THE COUPLED  
OCEAN-ATMOSPHERE SYSTEM REFLECTED ENSO-NEUTRAL. LA NIƱA IS MOST LIKELY TO  
EMERGE IN OCTOBER-NOVEMBER-DECEMBER (OND 2024) WITH A 57% CHANCE, AND IS  
EXPECTED TO PERSIST THROUGH JANUARY-FEBRUARY-MARCH (JFM) 2025.  
 
ENHANCED PROBABILITIES FAVORING ABOVE NORMAL TEMPERATURES ARE INDICATED FOR THE  
HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI, AND THE BIG ISLAND) IN DJF  
(DECEMBER-JANUARY-FEBRUARY) 2024-25, CONSISTENT WITH PRACTICALLY ALL C3S  
DYNAMICAL MODEL FORECASTS, A MAJORITY OF THE NMME DYNAMICAL MODEL FORECASTS,  
AND (FOR THE BIG ISLAND AND MAUI) THE STATISTICAL ENSO-OCN TOOL. PROBABILITIES  
FAVORING ABOVE NORMAL TEMPERATURES ARE EXPECTED TO INCREASE FROM SOUTHEAST TO  
NORTHWEST ACROSS THE ISLAND CHAIN. ABOVE NORMAL TEMPERATURES ARE FAVORED BY  
PRACTICALLY ALL NMME AND C3S MODEL INPUTS DURING JANUARY-FEBRUARY-MARCH (JFM)  
AND FEBRUARY-MARCH-APRIL (FMA) 2025, THOUGH THE ENSO-OCN FAVORS NEAR NORMAL  
TEMPERATURES. NEARLY ALL MODELS THAT CONSTITUTE THE NMME FAVOR RELATIVELY WARM  
TEMPERATURES ACROSS THE ARCHIPELAGO DURING MARCH-APRIL-MAY (MAM) AND  
APRIL-MAY-JUNE (AMJ) 2025. BEYOND AMJ 2025, THE FORECAST SIGNAL WEAKENS AT  
LONGER LEADS, IN LARGE PART DUE TO THE LACK OF CLEAR FORCING FROM ENSO AND THE  
CLIMATOLOGICAL SPRING BARRIER. THEREFORE, EC IS INDICATED FOR HAWAII BEGINNING  
IN MAY-JUNE-JULY (MJJ) AND EXTENDING THROUGH LONGER LEADS.  
 
FOR DJF 2024-25 PRECIPITATION, MOST NMME AND C3S DYNAMICAL MODEL FORECASTS  
DEPICT ABOVE NORMAL PRECIPITATION ACROSS HAWAII, WITH METEO-FRANCE THE MAIN  
OUTLIER FAVORING RELATIVELY DRY CONDITIONS. THE STATISTICAL CONSOLIDATION TOOL  
(STAT-CON) AND ITS CONSTITUENTS (CANONICAL CORRELATION ANALYSIS (CCA), OPTIMAL  
CLIMATE NORMALS (OCN), CONSTRUCTED ANALOG (CA) AND ENSO-OCN) PROVIDE  
CONFLICTING INDICATIONS AMID VERY WEAK PRECIPITATION SIGNALS FROM DJF THROUGH  
THE WINTER MONTHS AND INTO SPRING 2025. IN JFM 2025, ABOVE NORMAL PRECIPITATION  
CONTINUES TO BE FAVORED BY MOST NMME SOLUTIONS, THOUGH THE GFDL SPEAR FORECASTS  
MIXED CONDITIONS OVER THE ISLANDS. THE IMME/C3S SOLUTIONS ALSO MOSTLY FAVOR  
RELATIVELY WET CONDITIONS, THOUGH ONCE AGAIN THE EXCEPTION IS THE METEO-FRANCE  
MODEL WHICH LEANS DRY. FOR FMA, THE C3S INPUTS METEO-FRANCE AND CMCC (CANADIAN)  
FAVOR A MIXED PRECIPITATION SIGNAL FOR HAWAII, WITH THE MAJORITY OF MODELS  
FAVORING ABOVE NORMAL PRECIPITATION. FOR THE NMME, NEARLY ALL MODELS PREDICT  
ABOVE NORMAL PRECIPITATION, EXCEPT FOR THE RELATIVELY DRY GFDL-SPEAR SOLUTION.  
MOST OF THE NMME SUITE OF MODELS CONTINUE TO FAVOR THE THEME OF ANOMALOUS  
WETNESS THROUGH MAM 2025, THOUGH BY AMJ THE UNCERTAINTY INCREASES  
SIGNIFICANTLY, FAVORING EC FOR THE ARCHIPELAGO. THE LACK OF STRONG FORCING FROM  
ENSO WARRANTS EC FOR THE REMAINING PRECIPITATION LEADS.  
 
HILO  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
DJF 2025 A40 72.8 0.4 A40 19.6 30.2 33.3  
JFM 2025 A50 71.8 0.4 A50 22.0 32.0 44.5  
FMA 2025 A50 71.7 0.4 A50 24.6 34.1 45.5  
MAM 2025 A50 72.0 0.5 A40 22.5 28.4 34.0  
AMJ 2025 A40 72.9 0.5 EC 21.4 23.7 29.0  
MJJ 2025 EC 74.0 0.4 EC 20.2 27.5 29.1  
JJA 2025 EC 75.2 0.4 EC 19.4 27.2 31.4  
JAS 2025 EC 76.1 0.4 EC 25.2 28.6 33.4  
ASO 2025 EC 76.4 0.4 EC 26.1 28.8 33.3  
SON 2025 EC 76.2 0.4 EC 24.3 30.2 40.8  
OND 2025 EC 75.5 0.4 EC 28.3 34.5 42.0  
NDJ 2025 EC 74.2 0.4 EC 26.4 36.6 43.0  
DJF 2026 EC 72.8 0.4 EC 19.6 30.2 33.3  
KAHULUI  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
DJF 2025 A50 73.8 0.4 A45 4.6 6.9 8.7  
JFM 2025 A55 72.5 0.4 A55 4.2 6.2 8.2  
FMA 2025 A60 72.3 0.4 A55 3.2 4.1 6.4  
MAM 2025 A55 73.0 0.4 A45 2.5 3.5 4.6  
AMJ 2025 A45 74.3 0.5 EC 1.2 1.6 2.2  
MJJ 2025 EC 76.0 0.5 EC 0.7 1.1 1.8  
JJA 2025 EC 77.7 0.4 EC 0.7 1.1 1.5  
JAS 2025 EC 79.0 0.4 EC 0.8 1.1 1.6  
ASO 2025 EC 79.4 0.4 EC 0.8 1.6 2.5  
SON 2025 EC 79.1 0.4 EC 2.1 3.3 4.8  
OND 2025 EC 77.8 0.4 EC 4.2 5.3 8.1  
NDJ 2025 EC 75.9 0.4 EC 5.2 7.6 9.5  
DJF 2026 EC 73.8 0.4 EC 4.6 6.9 8.7  
HONOLULU  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
DJF 2025 A60 75.3 0.5 A50 3.7 5.6 8.6  
JFM 2025 A60 73.9 0.4 A55 2.1 4.6 7.8  
FMA 2025 A60 73.8 0.4 A55 1.9 3.2 4.7  
MAM 2025 A55 74.8 0.4 A45 1.8 2.6 3.0  
AMJ 2025 A45 76.3 0.4 EC 1.2 1.6 1.8  
MJJ 2025 EC 78.2 0.4 EC 0.8 1.4 1.6  
JJA 2025 EC 79.9 0.4 EC 0.7 0.8 1.3  
JAS 2025 EC 81.3 0.4 EC 1.0 1.4 1.7  
ASO 2025 EC 81.7 0.4 EC 1.6 2.4 3.1  
SON 2025 EC 81.4 0.4 EC 2.5 4.0 5.6  
OND 2025 EC 80.0 0.4 EC 4.4 6.4 8.5  
NDJ 2025 EC 77.7 0.5 EC 3.9 5.6 8.8  
DJF 2026 EC 75.3 0.5 EC 3.7 5.6 8.6  
LIHUE  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
DJF 2025 A60 73.6 0.4 A50 7.5 8.4 14.0  
JFM 2025 A60 72.2 0.4 A60 6.5 8.8 13.8  
FMA 2025 A60 72.1 0.5 A60 5.8 8.4 9.9  
MAM 2025 A60 72.8 0.5 A50 5.3 6.6 8.0  
AMJ 2025 A50 74.2 0.5 EC 4.7 5.5 6.0  
MJJ 2025 EC 76.0 0.5 EC 4.9 5.4 5.9  
JJA 2025 EC 77.7 0.4 EC 4.4 5.3 6.9  
JAS 2025 EC 79.0 0.3 EC 5.3 6.1 7.8  
ASO 2025 EC 79.4 0.3 EC 6.2 7.9 8.4  
SON 2025 EC 79.1 0.3 EC 9.2 10.0 11.2  
OND 2025 EC 77.8 0.3 EC 9.2 11.7 15.6  
NDJ 2025 EC 75.7 0.3 EC 8.6 12.1 16.9  
DJF 2026 EC 73.6 0.4 EC 7.5 8.4 14.0  
FORECASTER: ANTHONY ARTUSA  
 
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 DEC 19, 2024.  
 
 
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