881
FXHW40 KWBC 191230
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EST THU MAR 19 2026
MONTHLY FORECAST DISCUSSION VALID APRIL 2026
SEA SURFACE TEMPERATURE (SST) ANOMALIES IN THE RANGE OF 0 TO +1 DEGREES CELSIUS
(C) WERE OBSERVED AROUND THE HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND THE BIG
ISLAND) DURING THE PREVIOUS WEEK WITH WARMER ANOMALIES NEAR KAUAI AND WEAKER
ANOMALIES NEAR THE BIG ISLAND OF HAWAII.
FROM JANUARY THROUGH FEBRUARY 2026, RAINFALL TOTAL ACCUMULATIONS WERE:
LIHUE AIRPORT 7.09 INCHES (111 PERCENT OF AVERAGE)
HONOLULU AIRPORT 3.71 INCHES (98 PERCENT OF AVERAGE)
KAHULUI AIRPORT 4.23 INCHES (96 PERCENT OF AVERAGE)
HILO AIRPORT 25.96 INCHES (144 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 THE HAWAIIAN ISLANDS IN APRIL 2026. 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).
FOR THE APRIL 2026 PRECIPITATION OUTLOOK, THE PROBABILITY OF ABOVE NORMAL
PRECIPITATION IS ELEVATED FOR ALL ISLANDS OF HAWAII. THE OUTLOOK IS CONSISTENT
WITH MOST MODELS OF THE NMME AND IMME, AS WELL AS STATISTICAL FORECASTS FROM
THE CONSTRUCTED ANALOG (CA).
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO A50 72.6 0.7 A45 7.4 8.9 11.2
KAHULUI A50 74.1 0.6 A45 0.5 0.9 1.3
HONOLULU A50 76.3 0.5 A45 0.3 0.5 0.7
LIHUE A50 74.0 0.6 A45 1.6 1.9 2.8
SEASONAL FORECAST DISCUSSION VALID AMJ 2026 - AMJ 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 CONDITIONS CONTINUED INTO MARCH 2026. SST ANOMALIES ARE NEGATIVE OVER
THE EAST-CENTRAL EQUATORIAL PACIFIC. SST ANOMALIES WERE POSITIVE OVER THE
WESTERN TROPICAL PACIFIC OCEAN AND THE EQUATORIAL PACIFIC TO THE EAST OF ABOUT
120 DEGREES WEST LONGITUDE. AVERAGE RELATIVE SST ANOMALIES FOR THE NIñO 3.4
REGION ARE CURRENTLY ABOUT -0.5 DEGREES C, THE THRESHOLD BETWEEN LA NIñA AND
ENSO-NEUTRAL CONDITIONS, WHERE RELATIVE SST ANOMALIES SUBTRACT THE AVERAGE
GLOBAL TROPICAL SST ANOMALY BETWEEN 20 DEGREES S AND 20 DEGREES N LATITUDE. THE
MOST RECENT 3-MONTH RELATIVE OCEAN NIñO INDEX (RONI) IS -0.9 C FOR THE
DECEMBER THROUGH FEBRUARY PERIOD, INDICATING A RELATIVELY STRONGER LA NIñA
DURING WINTER THAT IS CURRENTLY WEAKENING. POSITIVE SST ANOMALIES ARE OBSERVED
ACROSS MOST OF THE TROPICAL PACIFIC OCEAN TO THE NORTH OF 10 DEGREES N
LATITUDE.
ABOVE-AVERAGE SUBSURFACE OCEAN TEMPERATURES HAVE EXPANDED ACROSS THE ENTIRE
EQUATORIAL PACIFIC OCEAN AT DEPTHS GREATER THAN 200 METERS IN THE WESTERN
PACIFIC AND 150 METERS IN THE EASTERN PACIFIC, AND EXTENDING TO THE SURFACE IN
THE FAR EASTERN EQUATORIAL PACIFIC. ABOVE-AVERAGE OUTGOING LONGWAVE RADIATION
(OLR), ASSOCIATED WITH SUPPRESSED CONVECTION AND PRECIPITATION, IS OBSERVED
AROUND THE DATE LINE IN THE EQUATORIAL PACIFIC OCEAN, WHILE BELOW-AVERAGE OLR,
ASSOCIATED WITH ENHANCED CONVECTION AND PRECIPITATION, IS OBSERVED OVER MUCH OF
THE MARITIME CONTINENT AND NORTHERN AUSTRALIA. EASTERLY LOW-LEVEL (850-HPA)
WIND ANOMALIES ARE ENHANCED OVER THE CENTRAL EQUATORIAL PACIFIC, WHILE
UPPER-LEVEL (200-HPA) WIND ANOMALIES ARE WESTERLY OVER THE EAST-CENTRAL
EQUATORIAL PACIFIC.
THE MADDEN JULIAN OSCILLATION (MJO) HAS CIRCLED THE GLOBE IN RECENT WEEKS BUT
HAS SHOWN SIGNS OF INTERFERENCE WITH OTHER TROPICAL VARIABILITY, REMAINING
RELATIVELY WEAK. THE REAL-TIME MULTIVARIATE MJO (RMM) INDEX HAS RECENTLY
STRENGTHENED IN PHASE 7 IN THE WESTERN PACIFIC OCEAN. MODELS PREDICT EASTWARD
PROPAGATION IN THE NEXT WEEK. HOWEVER DYNAMICAL MODEL FORECASTS DIVERGE AND
INDICATE SIGNIFICANT UNCERTAINTY IN THE MJO IN THE FOLLOWING WEEKS, WITH SOME
MODEL REALIZATIONS PREDICTING A STRONG MJO TO PROPAGATE ACROSS THE WESTERN
HEMISPHERE INTO THE INDIAN OCEAN, WHILE OTHER SOLUTIONS PREDICT THE MJO SIGNAL
TO QUICKLY WEAKEN. MJO ACTIVITY MAY ENHANCE PRECIPITATION OVER THE CENTRAL
PACIFIC AND HAWAII IN THE NEXT TWO TO THREE WEEKS, AT THE END OF MARCH AND THE
BEGINNING OF APRIL. THE IMPACTS OF THE MJO FOR HAWAII ARE UNCERTAIN FOR THE
REMAINDER OF APRIL.
DYNAMICAL AND STATISTICAL MODELS PREDICT A TRANSITION FROM LA NIñA TO
ENSO-NEUTRAL CONDITIONS IN THE NEXT MONTH. SOME MODELS, SUCH AS THE NCEP
CLIMATE FORECAST SYSTEM (CFSV2) AND THE CPC SST CONSTRUCTED ANALOG (CA) PREDICT
A RAPID INCREASE IN SEA SURFACE TEMPERATURES, WITH THE POTENTIAL FOR
DEVELOPMENT OF EL NIñO CONDITIONS, WITH NIñO 3.4 ANOMALIES EXCEEDING +0.5
DEGREES C, BY THE END OF BOREAL SPRING (JUNE). WHILE THE CPC SST CANONICAL
CORRELATION ANALYSIS (CCA) PREDICTS ENSO-NEUTRAL CONDITIONS AND A WEAKER
POSITIVE NIñO 3.4 ANOMALY TO EMERGE IN SPRING, THE CCA FAVORS ENSO-NEUTRAL
CONDITIONS TO PERSIST THROUGH SUMMER. THE CPC ENSO OUTLOOK FORECASTS
ENSO-NEUTRAL CONDITIONS WITH GREATER THAN A 90% CHANCE IN THE THREE-MONTH
MARCH-APRIL-MAY (MAM) SEASON. HOWEVER, EL NIñO CONDITIONS ARE MORE LIKELY THAN
ENSO-NEUTRAL IN SUMMER AND AUTUMN 2026. ENSO-NEUTRAL CONDITIONS ARE EXPECTED TO
BE IN PLACE FOR THE HAWAII OUTLOOK FOR APRIL AND THE NEXT THREE MONTH SEASON,
WHILE POTENTIAL EL NIñO CONDITIONS IMPACT THE OUTLOOKS IN SUMMER AND EARLY
AUTUMN. HISTORICALLY, EL NIñO CONDITIONS FAVOR ABOVE NORMAL PRECIPITATION FOR
HAWAII IN THE BOREAL SUMMER AND EARLY AUTUMN. THE HAWAII SEASONAL OUTLOOK FOR
TEMPERATURE AND PRECIPITATION IS BASED PRIMARILY ON DYNAMICAL MODEL FORECASTS
FROM THE NMME AND STATISTICAL FORECASTS, INCLUDING THE CA. THE IMPACTS OF THE
ENSO ON THE TEMPERATURE AND PRECIPITATION FOR HAWAII WEAKEN IN BOREAL AUTUMN,
LEADING TO INCREASED UNCERTAINTY IN THE HAWAII SEASONAL OUTLOOK FOR TEMPERATURE
AND PRECIPITATION IN THESE SEASONS.
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE PREDICTED IN THE
OUTLOOK FOR LIHUE, HONOLULU, KAHULUI AND HILO BEGINNING IN APRIL-MAY-JUNE (AMJ)
AND CONTINUING THROUGH AUGUST-SEPTEMBER-OCTOBER (ASO) 2026, SUPPORTED BY NEARLY
ALL DYNAMICAL MODEL FORECASTS FROM THE NMME AND C3S, THE CA STATISTICAL MODEL,
AND CONSISTENT WITH DECADAL TIMESCALE TEMPERATURE TRENDS FOR THE REGION. DUE TO
INCREASING UNCERTAINTY IN THE IMPACTS 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 SEPTEMBER-OCTOBER-NOVEMBER
(SON) 2026 AND EXTENDING THROUGH LONGER LEADS.
ENHANCED PROBABILITIES FOR ABOVE NORMAL PRECIPITATION ARE FORECAST OVER ALL
HAWAIIAN ISLANDS, KAUAI, OAHU, MAUI AND THE BIG ISLAND, FOR AMJ AND
MAY-JUNE-JULY (MJJ) 2026, ASSOCIATED IN PART WITH PREDICTED POSITIVE SST
ANOMALIES NEAR THE ISLANDS, AS PREDICTED ENSO-NEUTRAL CONDITIONS EMERGE. IN
JUNE-JULY-AUGUST (JJA) 2026, EC IS INDICATED IN THE SEASONAL PRECIPITATION
OUTLOOK, DUE TO UNCERTAINTY IN THE STATE OF ENSO AND WEAKER SIGNALS IN FORECAST
TOOLS. ABOVE NORMAL PRECIPITATION IS MORE LIKELY TO OCCUR IN THE
JULY-AUGUST-SEPTEMBER (JAS) AND ASO SEASONS, SUPPORTED BY THE NMME AND CA
FORECASTS AND POSSIBLY LINKED TO AN EMERGING EL NIñO. IN SON 2026 THROUGH
LONGER LEADS, EC IS INDICATED IN THE SEASONAL PRECIPITATION OUTLOOK, AS THE
IMPACT OF EL NIñO ON THE CLIMATE OF HAWAII WEAKENS IN AUTUMN. IF AN EL NIñO
EVENT EMERGES BY BOREAL AUTUMN, IT WILL LIKELY PERSIST INTO WINTER.
HISTORICALLY, EL NIñO CONDITIONS LEAD TO BELOW-AVERAGE PRECIPITATION FOR THE
HAWAIIAN ISLANDS IN BOREAL WINTER. HOWEVER, DUE TO UNCERTAINTY IN MODEL
FORECASTS FOR LONGER LEADS, EC IS INDICATED FOR THE PRECIPITATION OUTLOOK.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
AMJ 2026 A55 72.9 0.5 A45 21.4 23.7 29.0
MJJ 2026 A50 74.0 0.4 A40 20.2 27.5 29.1
JJA 2026 A50 75.2 0.4 EC 19.4 27.2 31.4
JAS 2026 A45 76.1 0.4 A40 25.2 28.6 33.4
ASO 2026 A40 76.4 0.4 A45 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
FMA 2027 EC 71.7 0.4 EC 24.6 34.1 45.5
MAM 2027 EC 72.0 0.5 EC 22.5 28.4 34.0
AMJ 2027 EC 72.9 0.5 EC 21.4 23.7 29.0
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
AMJ 2026 A55 74.3 0.5 A45 1.2 1.6 2.2
MJJ 2026 A50 76.0 0.5 A40 0.7 1.1 1.8
JJA 2026 A50 77.7 0.4 EC 0.7 1.1 1.5
JAS 2026 A45 79.0 0.4 A40 0.8 1.1 1.6
ASO 2026 A40 79.4 0.4 A45 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
FMA 2027 EC 72.3 0.4 EC 3.2 4.1 6.4
MAM 2027 EC 73.0 0.4 EC 2.5 3.5 4.6
AMJ 2027 EC 74.3 0.5 EC 1.2 1.6 2.2
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
AMJ 2026 A55 76.3 0.4 A45 1.2 1.6 1.8
MJJ 2026 A50 78.2 0.4 A40 0.8 1.4 1.6
JJA 2026 A50 79.9 0.4 EC 0.7 0.8 1.3
JAS 2026 A45 81.3 0.4 A40 1.0 1.4 1.7
ASO 2026 A40 81.7 0.4 A45 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
FMA 2027 EC 73.8 0.4 EC 1.9 3.2 4.7
MAM 2027 EC 74.8 0.4 EC 1.8 2.6 3.0
AMJ 2027 EC 76.3 0.4 EC 1.2 1.6 1.8
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
AMJ 2026 A55 74.2 0.5 A45 4.7 5.5 6.0
MJJ 2026 A50 76.0 0.5 A40 4.9 5.4 5.9
JJA 2026 A50 77.7 0.4 EC 4.4 5.3 6.9
JAS 2026 A45 79.0 0.3 A40 5.3 6.1 7.8
ASO 2026 A40 79.4 0.3 A45 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
FMA 2027 EC 72.1 0.5 EC 5.8 8.4 9.9
MAM 2027 EC 72.8 0.5 EC 5.3 6.6 8.0
AMJ 2027 EC 74.2 0.5 EC 4.7 5.5 6.0
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 APR 16, 2026.
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