Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
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FXHW40 KWBC 161231
PMDHCO
Prognostic Discussion for Long-Lead Hawaiian Outlooks
NWS Climate Prediction Center College Park MD
830AM EDT Thu Oct 16 2025
MONTHLY FORECAST DISCUSSION VALID NOVEMBER 2025
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 September 2025, rainfall total accumulations were:
Lihue Airport 15.73 inches (65 percent of average)
Honolulu Airport 9.68 inches (92 percent of average)
Kahului Airport 6.66 inches (62 percent of average)
Hilo Airport 38.17 inches (46 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 November 2025, though the anomalies
surrounding the Big Island are marginally warm. The main dissenter in opinion
is the CanESM5 forecast, which depicts near-normal SSTs around all but far
northwestern parts of the island chain, where slightly warmer-than-normal SSTs
are predicted. Based on model SST and surface air temperature forecasts, above
normal temperatures are favored for Kauai (Lihue), Oahu (Honolulu) and Maui
(Kahului) with greater probabilities for the northwestern islands of Oahu and
Kauai. Though a few solutions favor near-normal temperatures for the Big
Island, the majority of them favor slightly warmer-than-normal temperatures.
For the November 2025 precipitation outlook, a variety of outcomes is depicted
by the models. Therefore, Equal Chances (EC) of below, near, and above-normal
precipitation is favored.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
Hilo A40 74.4 0.4 EC 8.7 11.4 17.1
Kahului A45 76.0 0.6 EC 1.2 1.8 2.6
Honolulu A55 77.8 0.6 EC 0.9 1.4 2.1
Lihue A60 75.8 0.5 EC 2.6 3.5 5.5
SEASONAL FORECAST DISCUSSION VALID NDJ 2025 - NDJ 2026
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 Nio
Southern Oscillation (ENSO) outlook and other climate conditions relevant to
the seasonal outlook.
La Nia conditions emerged in September 2025. Equatorial SSTs were near to
below average across most of the central and eastern Pacific Ocean, and above
average in the western Pacific Ocean. Below-average subsurface ocean
temperatures strengthened across the central and eastern Pacific, while
above-average subsurface temperatures persisted in the western Pacific.
Above-average outgoing longwave radiation (OLR), associated with suppressed
convection and precipitation, are observed over the Date Line. Over the western
and east-central Pacific, low-level wind anomalies were easterly and
upper-level wind anomalies were westerly. The CPC ENSO Outlook forecasts La
Nia to continue through Dec-Jan-Feb (DJF) 2025-26, with a transition to
ENSO-neutral likely in JFM 2026 (55% chance).
Enhanced probabilities for above normal temperatures are predicted in the
outlook for Kauai, Oahu, Maui, and the Big Island from NDJ 2025 through MAM
2026, supported by nearly all dynamical model forecasts from the NMME and C3S
(through lead 3). Probabilities for above normal temperatures are greater for
northwestern islands of Hawaii, following calibrated model guidance from the
NMME and C3S. Due to increasing 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
April-May-June (AMJ) 2026 and extending through longer leads.
Enhanced probabilities for above normal precipitation are forecast over the
island chain from NDJ 2025 through MAM 2026, supported by most of the dynamical
model forecast tools. This is often (but not always) the case during a cold
season La Nia, and is related to the tendency of the jet to bifurcate
upstream. On occasion, a robust subtropical cyclone, often referred to as a
Kona Low, travels with the southern branch of the split jet, and 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. 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).
Similar to the temperature outlooks, the greatest probabilities favoring
positive anomalies are for the northwestern islands, with reduced odds over the
southeastern islands. 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 AMJ 2026 and continuing through the final season, NDJ 2026.
Hilo
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 2025 A40 74.2 0.4 A40 26.4 36.6 43.0
DJF 2026 A40 72.8 0.4 A40 19.6 30.2 33.3
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 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
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
Kahului
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 2025 A50 75.9 0.4 A45 5.2 7.6 9.5
DJF 2026 A45 73.8 0.4 A45 4.6 6.9 8.7
JFM 2026 A45 72.5 0.4 A40 4.2 6.2 8.2
FMA 2026 A40 72.3 0.4 A40 3.2 4.1 6.4
MAM 2026 A40 73.0 0.4 A40 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
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
Honolulu
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 2025 A60 77.7 0.5 A55 3.9 5.6 8.8
DJF 2026 A55 75.3 0.5 A50 3.7 5.6 8.6
JFM 2026 A45 73.9 0.4 A50 2.1 4.6 7.8
FMA 2026 A40 73.8 0.4 A45 1.9 3.2 4.7
MAM 2026 A40 74.8 0.4 A40 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
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
Lihue
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 2025 A65 75.7 0.3 A60 8.6 12.1 16.9
DJF 2026 A60 73.6 0.4 A55 7.5 8.4 14.0
JFM 2026 A50 72.2 0.4 A50 6.5 8.8 13.8
FMA 2026 A45 72.1 0.5 A50 5.8 8.4 9.9
MAM 2026 A40 72.8 0.5 A45 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
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
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 Nov 20, 2025.
$$