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FXHW40 KWBC 181331
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EST THU DEC 18 2025
MONTHLY FORECAST DISCUSSION VALID JANUARY 2026
SEA-SURFACE TEMPERATURE (SST) ANOMALIES IN THE RANGE OF +0.5 TO +1.0 DEGREE
CELSIUS (C) WERE OBSERVED AROUND THE HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND
THE BIG ISLAND) DURING THE PREVIOUS WEEK, WITH THE WARMEST ANOMALIES AROUND
KAUAI.
FROM JANUARY THROUGH NOVEMBER 2025, RAINFALL TOTAL ACCUMULATIONS WERE:
LIHUE AIRPORT 21.22 INCHES (67 PERCENT OF AVERAGE)
HONOLULU AIRPORT 10.23 INCHES (72 PERCENT OF AVERAGE)
KAHULUI AIRPORT 7.86 INCHES (59 PERCENT OF AVERAGE)
HILO AIRPORT 55.11 INCHES (51 PERCENT OF AVERAGE)
MOST CLIMATE MODELS OF THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE
INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME/C3S) PREDICT POSITIVE SST ANOMALIES
AROUND MOST OF THE HAWAIIAN ISLANDS IN JANUARY 2026, THOUGH THE ANOMALIES
SURROUNDING THE BIG ISLAND ARE MARGINALLY WARM. BASED ON MODEL SST AND SURFACE
AIR TEMPERATURE FORECASTS, ABOVE NORMAL TEMPERATURES ARE FAVORED FOR KAUAI
(LIHUE), OAHU (HONOLULU), MAUI (KAHULUI), AND THE BIG ISLAND (HILO), WITH THE
HIGHEST ODDS GENERALLY OVER KAUAI.
FOR THE JANUARY 2026 PRECIPITATION OUTLOOK, MOST MODEL SOLUTIONS INDICATE
WETTER-THAN-NORMAL CONDITIONS, WITH THE HIGHEST PROBABILITIES FAVORED AROUND
KAUAI.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO A40 71.6 0.5 A40 3.1 8.9 11.8
KAHULUI A45 72.1 0.6 A45 1.2 2.3 2.8
HONOLULU A55 73.3 0.5 A50 0.7 1.1 2.1
LIHUE A60 71.8 0.7 A55 1.3 2.2 4.8
SEASONAL FORECAST DISCUSSION VALID JFM 2026 - JFM 2027
REFER TO THE PROGNOSTIC DISCUSSION OF THE LONG-LEAD SEASONAL OUTLOOKS FOR THE
CONTIGUOUS U.S. (CONUS) AND ALASKA FOR FURTHER DESCRIPTION OF THE EL NIñO
SOUTHERN OSCILLATION (ENSO) OUTLOOK AND OTHER CLIMATE CONDITIONS RELEVANT TO
THE SEASONAL OUTLOOK.
LA NIñA PERSISTED IN NOVEMBER, AS INDICATED BY THE CONTINUATION OF
BELOW-AVERAGE SSTS ACROSS THE CENTRAL AND EASTERN EQUATORIAL PACIFIC, AND
ABOVE-AVERAGE SSTS OVER THE WESTERN EQUATORIAL PACIFIC. RECENT NEGATIVE
SUBSURFACE TEMPERATURE ANOMALIES WEAKENED SLIGHTLY (AVERAGED FROM 180-100W),
BUT BELOW-AVERAGE TEMPERATURES CONTINUED FROM THE SURFACE TO 200M DEPTH IN THE
EASTERN HALF OF THE EQUATORIAL PACIFIC. THE TROPICAL ATMOSPHERE REFLECTED LA
NIñA, WITH LOW-LEVEL EASTERLY WIND ANOMALIES EVIDENT IN THE CENTRAL PACIFIC,
AND UPPER-LEVEL WESTERLY WIND ANOMALIES OBSERVED ACROSS MOST OF THE EQUATORIAL
PACIFIC OCEAN. ENHANCED CONVECTION PERSISTED OVER INDONESIA AND SUPPRESSED
CONVECTION WAS NEAR THE DATE LINE. ACCORDING TO THE CPC ENSO TEAM, LA NIñA IS
FAVORED TO CONTINUE FOR THE NEXT MONTH OR TWO, WITH A TRANSITION TO
ENSO-NEUTRAL MOST LIKELY IN JAN-FEB-MAR 2026 (68% CHANCE).
ENHANCED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE PREDICTED IN THE
OUTLOOK FOR KAUAI, OAHU, MAUI, AND THE BIG ISLAND FROM JFM 2026 THROUGH MAM
2026, SUPPORTED BY NEARLY ALL DYNAMICAL MODEL FORECASTS FROM THE NMME AND C3S.
FOR AMJ 2026, THE NMME CONTINUES TO DEPICT ENHANCED PROBABILITIES FOR
ABOVE-NORMAL TEMPERATURES FOR THE ISLANDS, WITH THE EXCEPTION OF THE CANADIAN
CANESM5 MODEL, WHICH FAVORS NEAR-NORMAL TEMPERATURES. IN GENERAL FOR THIS SET
OF OUTLOOKS FROM JFM TO AMJ 2026, PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES
ARE GREATER FOR NORTHWESTERN ISLANDS OF HAWAII, FOLLOWING CALIBRATED MODEL
GUIDANCE FROM THE MAJOR MODELS. DUE TO INCREASED UNCERTAINTY IN THE STATE OF
ENSO AND WEAKENING SIGNALS IN FORECAST GUIDANCE AT LONGER LEADS, EQUAL CHANCES
(EC) FOR ABOVE, NEAR OR BELOW-NORMAL TEMPERATURES ARE INDICATED FOR HAWAII
BEGINNING IN MAY-JUN-JUL (MJJ) 2026 AND EXTENDING THROUGH LONGER LEADS.
ENHANCED PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE FORECAST OVER THE
ISLAND CHAIN FROM JFM 2026 THROUGH AMJ 2026, SUPPORTED BY MOST (BUT NOT ALL) OF
THE AVAILABLE DYNAMICAL MODEL FORECAST TOOLS. SIMILAR TO THE TEMPERATURE
OUTLOOKS, THE GREATEST CHANCES FOR ABOVE-NORMAL PRECIPITATION ARE FOR THE
NORTHWESTERN ISLANDS, WITH THE SMALLEST CHANCES FOR ABOVE-NORMAL ACROSS THE
SOUTHEASTERN ISLANDS. ON OCCASION DURING A COLD SEASON LA NIñA, A ROBUST
SUBTROPICAL CYCLONE (OFTEN REFERRED TO AS A KONA LOW) APPROACHES THE HAWAIIAN
ISLANDS FROM THE NORTHWEST. THE HAWAIIAN WORD, KONA, MEANS LEEWARD AND IS USED
TO DESCRIBE WINDS WITH A SOUTHERLY COMPONENT THAT REPLACE THE USUALLY
PERSISTENT TRADE WIND REGIME, AND BRINGS PRECIPITATION ALSO TO THE
TYPICALLY-DRIER LEEWARD SLOPES. HISTORICALLY, KONA LOWS HAVE PRODUCED A VARIETY
OF WEATHER-RELATED HAZARDS, MOST NOTABLY HEAVY RAIN, FLOODS, AND HIGH WINDS
(MORRISON AND BUSINGER, 2001, WEATHER AND FORECASTING). EQUAL CHANCES (EC) FOR
ABOVE, NEAR OR BELOW NORMAL PRECIPITATION ARE INDICATED FOR THE ISLANDS OF
KAUAI, OAHU, MAUI, AND THE BIG ISLAND STARTING IN MJJ 2026 AND CONTINUING
THROUGH THE FINAL SEASON, JFM 2027.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JFM 2026 A40 71.8 0.4 A40 22.0 32.0 44.5
FMA 2026 A40 71.7 0.4 A40 24.6 34.1 45.5
MAM 2026 A40 72.0 0.5 A40 22.5 28.4 34.0
AMJ 2026 A40 72.9 0.5 A40 21.4 23.7 29.0
MJJ 2026 EC 74.0 0.4 EC 20.2 27.5 29.1
JJA 2026 EC 75.2 0.4 EC 19.4 27.2 31.4
JAS 2026 EC 76.1 0.4 EC 25.2 28.6 33.4
ASO 2026 EC 76.4 0.4 EC 26.1 28.8 33.3
SON 2026 EC 76.2 0.4 EC 24.3 30.2 40.8
OND 2026 EC 75.5 0.4 EC 28.3 34.5 42.0
NDJ 2026 EC 74.2 0.4 EC 26.4 36.6 43.0
DJF 2027 EC 72.8 0.4 EC 19.6 30.2 33.3
JFM 2027 EC 71.8 0.4 EC 22.0 32.0 44.5
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JFM 2026 A45 72.5 0.4 A45 4.2 6.2 8.2
FMA 2026 A45 72.3 0.4 A45 3.2 4.1 6.4
MAM 2026 A40 73.0 0.4 A40 2.5 3.5 4.6
AMJ 2026 A40 74.3 0.5 A40 1.2 1.6 2.2
MJJ 2026 EC 76.0 0.5 EC 0.7 1.1 1.8
JJA 2026 EC 77.7 0.4 EC 0.7 1.1 1.5
JAS 2026 EC 79.0 0.4 EC 0.8 1.1 1.6
ASO 2026 EC 79.4 0.4 EC 0.8 1.6 2.5
SON 2026 EC 79.1 0.4 EC 2.1 3.3 4.8
OND 2026 EC 77.8 0.4 EC 4.2 5.3 8.1
NDJ 2026 EC 75.9 0.4 EC 5.2 7.6 9.5
DJF 2027 EC 73.8 0.4 EC 4.6 6.9 8.7
JFM 2027 EC 72.5 0.4 EC 4.2 6.2 8.2
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JFM 2026 A60 73.9 0.4 A55 2.1 4.6 7.8
FMA 2026 A55 73.8 0.4 A50 1.9 3.2 4.7
MAM 2026 A50 74.8 0.4 A50 1.8 2.6 3.0
AMJ 2026 A45 76.3 0.4 A45 1.2 1.6 1.8
MJJ 2026 EC 78.2 0.4 EC 0.8 1.4 1.6
JJA 2026 EC 79.9 0.4 EC 0.7 0.8 1.3
JAS 2026 EC 81.3 0.4 EC 1.0 1.4 1.7
ASO 2026 EC 81.7 0.4 EC 1.6 2.4 3.1
SON 2026 EC 81.4 0.4 EC 2.5 4.0 5.6
OND 2026 EC 80.0 0.4 EC 4.4 6.4 8.5
NDJ 2026 EC 77.7 0.5 EC 3.9 5.6 8.8
DJF 2027 EC 75.3 0.5 EC 3.7 5.6 8.6
JFM 2027 EC 73.9 0.4 EC 2.1 4.6 7.8
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JFM 2026 A65 72.2 0.4 A60 6.5 8.8 13.8
FMA 2026 A60 72.1 0.5 A55 5.8 8.4 9.9
MAM 2026 A55 72.8 0.5 A50 5.3 6.6 8.0
AMJ 2026 A45 74.2 0.5 A45 4.7 5.5 6.0
MJJ 2026 EC 76.0 0.5 EC 4.9 5.4 5.9
JJA 2026 EC 77.7 0.4 EC 4.4 5.3 6.9
JAS 2026 EC 79.0 0.3 EC 5.3 6.1 7.8
ASO 2026 EC 79.4 0.3 EC 6.2 7.9 8.4
SON 2026 EC 79.1 0.3 EC 9.2 10.0 11.2
OND 2026 EC 77.8 0.3 EC 9.2 11.7 15.6
NDJ 2026 EC 75.7 0.3 EC 8.6 12.1 16.9
DJF 2027 EC 73.6 0.4 EC 7.5 8.4 14.0
JFM 2027 EC 72.2 0.4 EC 6.5 8.8 13.8
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 JAN 15, 2026.
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