887
FXHW40 KWBC 181252
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EST THU APR 18 2024
MONTHLY FORECAST DISCUSSION VALID APRIL 2024
SEA SURFACE TEMPERATURE (SST) ANOMALIES WERE NEAR-AVERAGE OVER THE HAWAIIAN
ISLANDS (KAUAI, OAHU, MAUI AND THE BIG ISLAND) DURING THE PREVIOUS WEEK, WITH
SLIGHTLY NEGATIVE SST ANOMALIES NEAR THE SOUTHEASTERN ISLANDS INCLUDING THE BIG
ISLAND.
FOR JANUARY THROUGH MARCH 2024, RAINFALL TOTAL ACCUMULATIONS WERE:
-LIHUE AIRPORT 4.41 INCHES (37 PERCENT OF NORMAL)
-HONOLULU AIRPORT 3.17 INCHES (52 PERCENT OF NORMAL)
-KAHULUI AIRPORT 6.70 INCHES (95 PERCENT OF NORMAL)
-HILO AIRPORT 24.78 INCHES (81 PERCENT OF NORMAL)
THE NCEP CLIMATE FORECAST SYSTEM (CFS) AND OTHER CLIMATE MODELS OF THE NORTH
AMERICAN MULTI-MODEL ENSEMBLE (NMME) PREDICT BELOW AVERAGE SSTS AROUND THE
SOUTHEASTERN ISLANDS INCLUDING THE BIG ISLAND THROUGH MAY 2024 AND NEAR AVERAGE
SSTS NEAR NORTHWESTERN ISLANDS. BASED PRIMARILY ON THESE SST FORECASTS, SURFACE
TEMPERATURES ARE ALSO FAVORED TO BE BELOW NORMAL FOR THE BIG ISLAND, WHILE
EQUAL CHANCES (EC) FOR ABOVE, NEAR OR BELOW NORMAL TEMPERATURES ARE FORECAST
FOR MAUI, KAUAI AND OAHU IN MAY 2024. FOR THE MAY 2024 PRECIPITATION OUTLOOK,
BELOW NORMAL PRECIPITATION CHANCES ARE ELEVATED FOR ALL OF THE ISLAND CHAIN, AS
INDICATED BY MOST DYNAMICAL MODEL FORECASTS, AND CONSISTENT WITH EL NIñO
CONDITIONS OVER THE TROPICAL PACIFIC.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO B40 72.6 0.7 B55 7.4 8.9 11.2
KAHULUI EC 74.1 0.6 B55 0.5 0.9 1.3
HONOLULU EC 76.3 0.5 B50 0.3 0.5 0.7
LIHUE EC 74.0 0.6 B50 1.6 1.9 2.8
SEASONAL FORECAST DISCUSSION VALID MJJ 2024 - MJJ 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. EL NIñO CONDITIONS ARE OBSERVED
OVER THE TROPICAL PACIFIC OCEAN. EQUATORIAL SEA SURFACE TEMPERATURES (SSTS) ARE
ABOVE AVERAGE ACROSS THE CENTRAL AND EAST-CENTRAL PACIFIC OCEAN. POSITIVE
SUBSURFACE TEMPERATURE ANOMALIES HAVE WEAKENED ACROSS THE EQUATORIAL PACIFIC
BUT REMAIN CLOSE TO THE SURFACE IN THE CENTRAL PACIFIC. NEGATIVE SUBSURFACE
TEMPERATURE ANOMALIES EXPANDED ACROSS THE EQUATORIAL PACIFIC AND BELOW-AVERAGE
TEMPERATURES HAVE REACHED THE SURFACE IN THE FAR EASTERN PACIFIC OCEAN.
LOW-LEVEL (850-HPA) WIND ANOMALIES WERE EASTERLY OVER A SMALL REGION IN THE
WEST-CENTRAL TROPICAL PACIFIC OCEAN, WHILE
UPPER-LEVEL WIND ANOMALIES (200-HPA) WERE NEAR AVERAGE OVER MOST OF THE
EQUATORIAL PACIFIC. CONVECTION AND PRECIPITATION WERE NEAR AVERAGE IN THE
CENTRAL AND EASTERN EQUATORIAL PACIFIC, AND SLIGHTLY SUPPRESSED AROUND THE
PHILIPPINES AND MALAYSIA. WHILE ATMOSPHERIC AND OCEANIC CONDITIONS OVER THE
TROPICAL PACIFIC ARE GENERALLY CONSISTENT WITH EL NIñO CONDITIONS, ATMOSPHERIC
ANOMALIES ARE WEAKENING. THERE IS A 85% CHANCE OF TRANSITION FROM EL NIñO TO
ENSO-NEUTRAL DURING APRIL-JUNE 2024, WITH ABOUT A 60% CHANCE OF LA NIñA
DEVELOPING IN JUNE-AUGUST 2024.
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE FORECAST FOR KAUAI,
OAHU AND MAUI AND EQUAL CHANCES (EC) FOR ABOVE, NEAR OR BELOW NORMAL
TEMPERATURES ARE FORECAST FOR THE BIG ISLAND IN MJJ (MAY-JUNE-JULY) 2024,
CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS FROM THE NMME. ENHANCED
PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE FORECAST FOR THE BIG ISLAND,
KAUAI, OAHU AND MAUI IN JJA (JUNE-JULY-AUGUST) 2024 THROUGH ASO
(AUGUST-SEPTEMBER-OCTOBER) 2023, CONSISTENT WITH THE NMME FORECAST. THE
FORECAST SIGNAL WEAKENS AT LONGER LEADS, THEREFORE EC IS INDICATED FOR HAWAII
BEGINNING IN SON (SEPTEMBER-OCTOBER-NOVEMBER) 2024 AND EXTENDING THROUGH ALL
LONGER LEADS THEREAFTER.
ENHANCED PROBABILITIES FOR BELOW NORMAL PRECIPITATION ARE FORECAST OVER THE
HAWAIIAN ISLANDS (KAUAI, OAHU, MAUI AND THE BIG ISLAND) FROM MJJ 2024 TO SON
2024, CONSISTENT WITH MOST DYNAMICAL AND STATISTICAL MODEL FORECASTS. DUE TO
CONSIDERABLE UNCERTAINTY IN THE PRECIPITATION FORECASTS FROM DYNAMICAL AND
STATISTICAL MODELS, EC IS INDICATED OVER THE HAWAIIAN ISLANDS BEGINNING IN OND
(OCTOBER-NOVEMBER-DECEMBER) 2024 THROUGH LONGER LEADS.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
MJJ 2024 EC 74.0 0.4 B60 20.2 27.5 29.1
JJA 2024 A40 75.2 0.4 B60 19.4 27.2 31.4
JAS 2024 A40 76.1 0.4 B50 25.2 28.6 33.4
ASO 2024 A40 76.4 0.4 B45 26.1 28.8 33.3
SON 2024 EC 76.2 0.4 B40 24.3 30.2 40.8
OND 2024 EC 75.5 0.4 EC 28.3 34.5 42.0
NDJ 2024 EC 74.2 0.4 EC 26.4 36.6 43.0
DJF 2025 EC 72.8 0.4 EC 19.6 30.2 33.3
JFM 2025 EC 71.8 0.4 EC 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 2024 EC 74.0 0.4 EC 20.2 27.5 29.1
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
MJJ 2024 EC 76.0 0.5 B60 0.7 1.1 1.8
JJA 2024 A40 77.7 0.4 B55 0.7 1.1 1.5
JAS 2024 A45 79.0 0.4 B50 0.8 1.1 1.6
ASO 2024 A45 79.4 0.4 B45 0.8 1.6 2.5
SON 2024 EC 79.1 0.4 B40 2.1 3.3 4.8
OND 2024 EC 77.8 0.4 EC 4.2 5.3 8.1
NDJ 2024 EC 75.9 0.4 EC 5.2 7.6 9.5
DJF 2025 EC 73.8 0.4 EC 4.6 6.9 8.7
JFM 2025 EC 72.5 0.4 EC 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 2024 EC 76.0 0.5 EC 0.7 1.1 1.8
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
MJJ 2024 EC 78.2 0.4 B50 0.8 1.4 1.6
JJA 2024 A40 79.9 0.4 B50 0.7 0.8 1.3
JAS 2024 A45 81.3 0.4 B45 1.0 1.4 1.7
ASO 2024 A45 81.7 0.4 B45 1.6 2.4 3.1
SON 2024 EC 81.4 0.4 B40 2.5 4.0 5.6
OND 2024 EC 80.0 0.4 EC 4.4 6.4 8.5
NDJ 2024 EC 77.7 0.5 EC 3.9 5.6 8.8
DJF 2025 EC 75.3 0.5 EC 3.7 5.6 8.6
JFM 2025 EC 73.9 0.4 EC 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 2024 EC 78.2 0.4 EC 0.8 1.4 1.6
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
MJJ 2024 A40 76.0 0.5 B50 4.9 5.4 5.9
JJA 2024 A40 77.7 0.4 B50 4.4 5.3 6.9
JAS 2024 A45 79.0 0.3 B45 5.3 6.1 7.8
ASO 2024 A45 79.4 0.3 B40 6.2 7.9 8.4
SON 2024 EC 79.1 0.3 B40 9.2 10.0 11.2
OND 2024 EC 77.8 0.3 EC 9.2 11.7 15.6
NDJ 2024 EC 75.7 0.3 EC 8.6 12.1 16.9
DJF 2025 EC 73.6 0.4 EC 7.5 8.4 14.0
JFM 2025 EC 72.2 0.4 EC 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 2024 EC 76.0 0.5 EC 4.9 5.4 5.9
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 NEXT MONTH, ON THU MAY 16, 2024.
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