945
FXHW40 KWBC 181231
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THU JUL 18 2024
MONTHLY FORECAST DISCUSSION VALID AUGUST 2024
SEA-SURFACE TEMPERATURE (SST) ANOMALIES NEAR ZERO DEGREES CELSIUS WERE OBSERVED
AROUND THE HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND THE BIG ISLAND) DURING THE
PREVIOUS WEEK.
FROM JANUARY THROUGH JUNE 2024, RAINFALL TOTAL ACCUMULATIONS WERE:
LIHUE AIRPORT 21.91 INCHES (122 PERCENT OF AVERAGE)
HONOLULU AIRPORT 9.54 INCHES (116 PERCENT OF AVERAGE)
KAHULUI AIRPORT 8.92 INCHES (96 PERCENT OF AVERAGE)
HILO AIRPORT 51.82 INCHES (95 PERCENT OF AVERAGE)
THE NCEP CLIMATE FORECAST SYSTEM (CFS) AND OTHER CLIMATE MODELS OF THE NORTH
AMERICAN MULTI-MODEL ENSEMBLE (NMME) GENERALLY PREDICT NEAR-AVERAGE SSTS AROUND
THE HAWAIIAN ISLANDS THROUGH AUGUST 2024. BASED PRIMARILY ON THESE SST
FORECASTS, SURFACE TEMPERATURES ARE INDICATED TO BE EQUAL CHANCES (EC) OF
BELOW, NEAR, AND ABOVE-NORMAL FOR ALL THE ISLANDS THROUGH AUGUST. FOR THE
AUGUST 2024 PRECIPITATION OUTLOOK, BELOW NORMAL PRECIPITATION PROBABILITIES ARE
ELEVATED FOR ALL OF THE ISLAND CHAIN, AS INDICATED BY MOST DYNAMICAL MODEL
FORECASTS, AND CONSISTENT WITH A TRANSITION FROM ENSO-NEUTRAL TO LA NIñA
CONDITIONS OVER THE TROPICAL PACIFIC IN THE NEAR FUTURE.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO EC 76.6 0.4 B45 7.6 8.4 10.3
KAHULUI EC 79.8 0.4 B45 0.3 0.5 0.6
HONOLULU EC 82.1 0.4 B50 0.1 0.2 0.4
LIHUE EC 79.7 0.4 B50 1.4 1.8 2.5
SEASONAL FORECAST DISCUSSION VALID ASO 2024 - ASO 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 ARE
OBSERVED OVER THE PACIFIC OCEAN. EQUATORIAL SSTS ARE ABOVE AVERAGE IN THE
WEST-CENTRAL PACIFIC OCEAN, AND NEAR TO BELOW AVERAGE IN THE EAST-CENTRAL AND
EASTERN PACIFIC OCEAN. NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES REMAIN IN THE
EASTERN HALF OF THE EQUATORIAL PACIFIC OCEAN, BUT HAVE WEAKENED IN THE LAST
MONTH. LOW-LEVEL (850-HPA) WIND ANOMALIES WERE EASTERLY ACROSS THE WESTERN
EQUATORIAL PACIFIC OCEAN, WHILE UPPER-LEVEL WINDS WERE NEAR AVERAGE OVER MOST
OF THE EQUATORIAL PACIFIC OCEAN. ENHANCED CONVECTION AND PRECIPITATION WAS
OBSERVED RECENTLY OVER PARTS OF THE MARITIME CONTINENT. MOST RECENT DYNAMICAL
AND STATISTICAL MODELS HAVE DELAYED THE DEVELOPMENT OF LA NIñA RELATIVE TO
LAST MONTH’S FORECASTS. HOWEVER LA NIñA IS FAVORED TO DEVELOP WITH A 70%
PROBABILITY DURING AUGUST-SEPTEMBER-OCTOBER AND PERSIST INTO THE NORTHERN
HEMISPHERE WINTER 2024-25 WITH NEAR 80% PROBABILITY.
EQUAL CHANCES (EC) FOR ABOVE, NEAR OR BELOW NORMAL TEMPERATURES ARE INDICATED
FOR LIHUE, HONOLULU, KAHULUI AND THE BIG ISLAND FROM ASO
(AUGUST-SEPTEMBER-OCTOBER) TO OND (OCTOBER-NOVEMBER-DECEMBER) 2024, CONSISTENT
WITH MOST DYNAMICAL MODEL FORECASTS FROM THE NMME AND C3S. ENHANCED
PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE FAVORED OVER THE HAWAIIAN
ISLANDS INCLUDING LIHUE, HONOLULU, KAHULUI, AND THE BIG ISLAND FROM NDJ
(NOVEMBER-DECEMBER-JANUARY) 2024-25 THROUGH JFM (JANUARY-FEBRUARY-MARCH) 2025,
SUPPORTED BY MOST OF THE DYNAMICAL MODEL AND STATISTICAL MODEL TEMPERATURE
FORECAST TOOLS. THE FORECAST SIGNAL WEAKENS AT LONGER LEADS, THEREFORE EC IS
INDICATED FOR HAWAII BEGINNING IN FMA (FEBRUARY-MARCH-APRIL) 2025 AND EXTENDING
THROUGH LONGER LEADS.
ENHANCED PROBABILITIES FOR BELOW NORMAL PRECIPITATION ARE FORECAST OVER THE
HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND THE BIG ISLAND) FROM ASO TO SON 2024,
CONSISTENT WITH MOST DYNAMICAL AND STATISTICAL MODEL FORECASTS. ENHANCED
PROBABILITIES OF ABOVE-NORMAL PRECIPITATION ARE PREDICTED FROM NDJ 2024 TO JFM
2025, CONSISTENT WITH IMPACTS OF A DEVELOPING LA NIñA AND DYNAMICAL MODEL
FORECASTS. DUE TO CONSIDERABLE UNCERTAINTY IN THE PRECIPITATION FORECASTS FROM
DYNAMICAL AND STATISTICAL MODELS, EC IS INDICATED OVER THE HAWAIIAN ISLANDS IN
OND 2024 AND BEGINNING FMA 2025 AND CONTINUING THROUGH LONGER LEADS.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
ASO 2024 EC 76.4 0.4 B50 26.1 28.8 33.3
SON 2024 EC 76.2 0.4 B45 24.3 30.2 40.8
OND 2024 EC 75.5 0.4 EC 28.3 34.5 42.0
NDJ 2024 A40 74.2 0.4 A40 26.4 36.6 43.0
DJF 2025 A45 72.8 0.4 A50 19.6 30.2 33.3
JFM 2025 A45 71.8 0.4 A45 22.0 32.0 44.5
FMA 2025 EC 71.7 0.4 EC 24.6 34.1 45.5
MAM 2025 EC 72.0 0.5 EC 22.5 28.4 34.0
AMJ 2025 EC 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
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
ASO 2024 EC 79.4 0.4 B50 0.8 1.6 2.5
SON 2024 EC 79.1 0.4 B45 2.1 3.3 4.8
OND 2024 EC 77.8 0.4 EC 4.2 5.3 8.1
NDJ 2024 A40 75.9 0.4 A40 5.2 7.6 9.5
DJF 2025 A45 73.8 0.4 A50 4.6 6.9 8.7
JFM 2025 A45 72.5 0.4 A45 4.2 6.2 8.2
FMA 2025 EC 72.3 0.4 EC 3.2 4.1 6.4
MAM 2025 EC 73.0 0.4 EC 2.5 3.5 4.6
AMJ 2025 EC 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
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
ASO 2024 EC 81.7 0.4 B50 1.6 2.4 3.1
SON 2024 EC 81.4 0.4 B45 2.5 4.0 5.6
OND 2024 EC 80.0 0.4 EC 4.4 6.4 8.5
NDJ 2024 A40 77.7 0.5 A40 3.9 5.6 8.8
DJF 2025 A45 75.3 0.5 A50 3.7 5.6 8.6
JFM 2025 A45 73.9 0.4 A45 2.1 4.6 7.8
FMA 2025 EC 73.8 0.4 EC 1.9 3.2 4.7
MAM 2025 EC 74.8 0.4 EC 1.8 2.6 3.0
AMJ 2025 EC 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
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
ASO 2024 EC 79.4 0.3 B50 6.2 7.9 8.4
SON 2024 EC 79.1 0.3 B45 9.2 10.0 11.2
OND 2024 EC 77.8 0.3 EC 9.2 11.7 15.6
NDJ 2024 A40 75.7 0.3 A40 8.6 12.1 16.9
DJF 2025 A45 73.6 0.4 A50 7.5 8.4 14.0
JFM 2025 A45 72.2 0.4 A45 6.5 8.8 13.8
FMA 2025 EC 72.1 0.5 EC 5.8 8.4 9.9
MAM 2025 EC 72.8 0.5 EC 5.3 6.6 8.0
AMJ 2025 EC 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
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 AUG 15, 2024.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page