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FXHW40 KWBC 191230
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THU JUN 19 2025
MONTHLY FORECAST DISCUSSION VALID JULY 2025
SEA-SURFACE TEMPERATURE (SST) ANOMALIES IN THE RANGE OF +0.5 TO +1.0 DEGREES
CELSIUS (C) WERE OBSERVED AROUND THE HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND
THE BIG ISLAND) DURING THE PREVIOUS WEEK.
FROM JANUARY THROUGH MAY 2025, RAINFALL TOTAL ACCUMULATIONS WERE:
LIHUE AIRPORT 8.64 INCHES (53 PERCENT OF AVERAGE)
HONOLULU AIRPORT 8.82 INCHES (114 PERCENT OF AVERAGE)
KAHULUI AIRPORT 6.44 INCHES (71 PERCENT OF AVERAGE)
HILO AIRPORT 24.76 INCHES (53 PERCENT OF AVERAGE)
MOST CLIMATE MODELS OF THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE
INTERNATIONAL MULTI-MODEL ENSEMBLE (IMME/C3S) PREDICT NEAR TO SLIGHTLY ABOVE
NORMAL SSTS FOR THE BIG ISLAND IN JULY 2025, WITH SOMEWHAT HIGHER PROBABILITIES
FAVORING ABOVE NORMAL SSTS FOR THE REMAINDER OF THE ISLAND CHAIN. AS IS MOST
OFTEN THE CASE, THE HAWAIIAN SURFACE TEMPERATURE PATTERN MIRRORS THAT OF THE
SURROUNDING SST ANOMALY PATTERN.
FOR THE JULY 2025 PRECIPITATION OUTLOOK, THERE IS SUBSTANTIAL VARIANCE BETWEEN
THE MODELS OF THE NMME AND IMME/C3S. HOWEVER, THE GENERAL TENDENCY FAVORS A
RELATIVELY DRY PATTERN FOR THE BIG ISLAND AND MAUI, WITH INCREASING CHANCES OF
RELATIVE WETNESS NORTHWESTWARD FROM MAUI (I.E. WITH WETNESS BEING SLIGHTLY MORE
LIKELY FOR KAUAI THAN FOR OAHU). A FEW MODELS (CFS, CANESM5, AND THE NCAR
CCSM4) FAVOR BELOW-NORMAL PRECIPITATION ACROSS THE ENTIRE ARCHIPELAGO.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO A40 76.2 0.4 B50 7.1 9.5 11.4
KAHULUI A45 79.2 0.4 B40 0.2 0.4 0.5
HONOLULU A50 81.4 0.5 EC 0.2 0.4 0.5
LIHUE A50 79.2 0.4 A40 1.5 1.7 1.9
SEASONAL FORECAST DISCUSSION VALID JAS 2025 - JAS 2026
REFER TO THE PROGNOSTIC DISCUSSION OF THE LONG-LEAD SEASONAL OUTLOOKS FOR THE
CONTIGUOUS U.S. (CONUS) AND ALASKA FOR A DESCRIPTION OF THE EL NIñO SOUTHERN
OSCILLATION (ENSO) OUTLOOK AND OTHER CLIMATE CONDITIONS RELEVANT TO THE
SEASONAL OUTLOOK. ENSO-NEUTRAL CONDITIONS CONTINUED OVER THE PACIFIC OCEAN
THROUGH MAY. EQUATORIAL SST ANOMALIES ARE NEAR TO SLIGHTLY ABOVE NORMAL ACROSS
MUCH OF THE PACIFIC OCEAN. WEAK NEGATIVE SST ANOMALIES ARE OBSERVED OVER PARTS
OF THE EASTERN EQUATORIAL PACIFIC OCEAN. NEGATIVE SUBSURFACE TEMPERATURE
ANOMALIES IN THE CENTRAL PACIFIC OCEAN HAVE DISSIPATED IN THE LAST SEVERAL
WEEKS. POSITIVE SUBSURFACE TEMPERATURE ANOMALIES PERSIST AT DEPTHS OF 75 TO 200
METERS IN THE WESTERN EQUATORIAL PACIFIC OCEAN. LOW-LEVEL (850-HPA) WIND
ANOMALIES ARE EASTERLY OVER THE EAST-CENTRAL PACIFIC, AND UPPER-LEVEL (200-HPA)
WIND ANOMALIES ARE NEAR AVERAGE ACROSS MOST OF THE PACIFIC OCEAN. ENHANCED
CONVECTION AND PRECIPITATION WERE OBSERVED OVER INDONESIA. COLLECTIVELY, THE
COUPLED OCEAN-ATMOSPHERE SYSTEM REFLECTS ENSO-NEUTRAL. MOST DYNAMICAL AND
STATISTICAL MODELS PREDICT A CONTINUATION OF ENSO-NEUTRAL CONDITIONS THROUGH
BOREAL SUMMER. SOME MODELS, SUCH AS THE CPC SST CANONICAL CORRELATION ANALYSIS
(CCA) PREDICT THE DEVELOPMENT OF A LA NIñA IN SUMMER BY FORECASTS OF NEGATIVE
NIñO 3.4 REGION SST ANOMALIES REACHING THE -0.5 C THRESHOLD IN JJA 2025,
DIPPING TO A MINIMUM OF ABOUT -1.2 C (MODERATE INTENSITY LA NIñA) IN NDJ AND
DJF 2025-26, AND THEN RECOVERING TO JUST ABOVE THE -0.5 C THRESHOLD BY NEXT
SPRING (AMJ 2026). ENSO-NEUTRAL CONDITIONS ARE FORECAST IN THE CPC ENSO OUTLOOK
WITH A GREATER PROBABILITY THAN LA NIñA THROUGH THE JANUARY-FEBRUARY-MARCH
(JFM) 2026 SEASON, ALTHOUGH THE PROBABILITY OF THE DEVELOPMENT OF LA NIñA
INCREASES THROUGH THE NORTHERN HEMISPHERE AUTUMN AND WINTER, COMING TO WITHIN
TEN PERCENTAGE POINTS DURING OND AND NDJ. DEVELOPMENT OF LA NIñA WOULD ALTER
THE PROBABILITIES OF PRECIPITATION FOR THE HAWAIIAN ISLANDS, ESPECIALLY IN
BOREAL WINTER, BUT THE STATE OF ENSO AT LONGER LEAD TIMES IS SOMEWHAT UNCERTAIN
AS OF LATE SPRING 2025.
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED IN THE
OFFICIAL OUTLOOK FOR LIHUE, HONOLULU, AND KAHULUI FROM JAS
(JULY-AUGUST-SEPTEMBER) THROUGH OCTOBER-NOVEMBER-DECEMBER (OND) 2025, FAVORED
BY MOST NMME AND AVAILABLE C3S DYNAMICAL MODELS AND DECADAL TEMPERATURE TRENDS.
MOST MODEL GUIDANCE SUPPORTS EQUAL CHANCES (EC) OF ABOVE, NEAR, AND BELOW
NORMAL SEASONAL MEAN TEMPERATURES FOR THE BIG ISLAND THROUGH OND, THOUGH A
SUBSTANTIAL NUMBER OF MODELS SUPPORT A WEAK TILT TOWARDS ABOVE NORMAL
TEMPERATURES. BY NDJ, THE TEMPERATURE OUTLOOK FOR ALL OF THE ISLANDS IS FAVORED
TO BE ABOVE NORMAL. THE CHANCES FOR ABOVE NORMAL TEMPERATURES ARE GREATER FOR
NORTHWESTERN ISLANDS OF HAWAII, AND GRADUALLY DIMINISH TOWARDS THE SOUTHEASTERN
ISLANDS.
ENHANCED PROBABILITIES FOR BELOW NORMAL PRECIPITATION ARE INDICATED OVER THE
BIG ISLAND OF HAWAII, MAUI, AND OAHU FROM JAS THROUGH
SEPTEMBER-OCTOBER-NOVEMBER (SON) 2025, CONSISTENT WITH MOST DYNAMICAL MODEL
FORECASTS, AS WELL AS DECADAL TRENDS. FOR KAUAI, WEAK OR CONFLICTING SIGNALS
WARRANTS EC FOR JAS, FOLLOWED BY A SLIGHT TILT TOWARDS BELOW NORMAL
PRECIPITATION IN BOTH ASO AND SON. FOR THE AUTUMN AND EARLY WINTER SEASONS OF
OND AND NDJ, A TRANSITION TOWARDS AN ANOMALOUSLY WET PATTERN IS PREDICTED BY
THE NMME AND ITS CONSTITUENT MODELS, INITIALLY FAVORING A FORECAST OF EC FOR
MOST ISLANDS IN OND, AND COMPLETING THE TRANSITION TO A WETTER PATTERN IN NDJ.
THE DYNAMICAL MODEL FORECASTS DEPICT KAUAI AS MOST LIKELY TO COMPLETE THE
TRANSITION TO A WETTER-THAN-NORMAL PATTERN FIRST, FAVORING ABOVE NORMAL
PRECIPITATION AS EARLY AS OND. THIS IS CONSISTENT WITH AN EXPECTED ENSO-NEUTRAL
BACKGROUND AND GENERALLY NEAR-AVERAGE TRADE WINDS, WITH CONSIDERATION OF
SIGNIFICANT PROBABILITIES FOR A LA NIñA EVENT AS WELL.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JAS 2025 EC 76.1 0.4 B60 25.2 28.6 33.4
ASO 2025 EC 76.4 0.4 B50 26.1 28.8 33.3
SON 2025 EC 76.2 0.4 B40 24.3 30.2 40.8
OND 2025 EC 75.5 0.4 EC 28.3 34.5 42.0
NDJ 2025 A40 74.2 0.4 A40 26.4 36.6 43.0
DJF 2026 EC 72.8 0.4 EC 19.6 30.2 33.3
JFM 2026 EC 71.8 0.4 EC 22.0 32.0 44.5
FMA 2026 EC 71.7 0.4 EC 24.6 34.1 45.5
MAM 2026 EC 72.0 0.5 EC 22.5 28.4 34.0
AMJ 2026 EC 72.9 0.5 EC 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
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JAS 2025 A40 79.0 0.4 B55 0.8 1.1 1.6
ASO 2025 A45 79.4 0.4 B45 0.8 1.6 2.5
SON 2025 A45 79.1 0.4 B40 2.1 3.3 4.8
OND 2025 A45 77.8 0.4 EC 4.2 5.3 8.1
NDJ 2025 A40 75.9 0.4 A40 5.2 7.6 9.5
DJF 2026 EC 73.8 0.4 EC 4.6 6.9 8.7
JFM 2026 EC 72.5 0.4 EC 4.2 6.2 8.2
FMA 2026 EC 72.3 0.4 EC 3.2 4.1 6.4
MAM 2026 EC 73.0 0.4 EC 2.5 3.5 4.6
AMJ 2026 EC 74.3 0.5 EC 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
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JAS 2025 A50 81.3 0.4 B45 1.0 1.4 1.7
ASO 2025 A50 81.7 0.4 B45 1.6 2.4 3.1
SON 2025 A55 81.4 0.4 B40 2.5 4.0 5.6
OND 2025 A45 80.0 0.4 EC 4.4 6.4 8.5
NDJ 2025 A40 77.7 0.5 A45 3.9 5.6 8.8
DJF 2026 EC 75.3 0.5 EC 3.7 5.6 8.6
JFM 2026 EC 73.9 0.4 EC 2.1 4.6 7.8
FMA 2026 EC 73.8 0.4 EC 1.9 3.2 4.7
MAM 2026 EC 74.8 0.4 EC 1.8 2.6 3.0
AMJ 2026 EC 76.3 0.4 EC 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
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
JAS 2025 A55 79.0 0.3 EC 5.3 6.1 7.8
ASO 2025 A60 79.4 0.3 B40 6.2 7.9 8.4
SON 2025 A60 79.1 0.3 B40 9.2 10.0 11.2
OND 2025 A50 77.8 0.3 A40 9.2 11.7 15.6
NDJ 2025 A40 75.7 0.3 A50 8.6 12.1 16.9
DJF 2026 EC 73.6 0.4 EC 7.5 8.4 14.0
JFM 2026 EC 72.2 0.4 EC 6.5 8.8 13.8
FMA 2026 EC 72.1 0.5 EC 5.8 8.4 9.9
MAM 2026 EC 72.8 0.5 EC 5.3 6.6 8.0
AMJ 2026 EC 74.2 0.5 EC 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
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 JUL 17, 2025.
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