Hawaii 30 & 90 Day Narrative

276 
FXHW40 KWBC 151620
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EST THU NOV 15 2018
MONTHLY FORECAST DISCUSSION VALID DECEMBER 2018
SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND POSITIVE ONE-HALF 
DEGREE TO POSITIVE ONE DEGREE C OVER KAUAI, OAHU AND MAUI, AND ABOUT POSITIVE 
ONE DEGREE TO POSITIVE TWO DEGREES C OVER THE BIG ISLAND. 
FOR JANUARY 2018 THROUGH THE END OF OCTOBER 2018, RAINFALL TOTAL ACCUMULATIONS 
WERE:
- LIHUE AIRPORT 44.18 INCHES (161 PERCENT OF NORMAL)
- HONOLULU AIRPORT 15.99 INCHES (140 PERCENT OF NORMAL)
- KAHULUI AIRPORT 19.70 INCHES (160 PERCENT OF NORMAL)
- HILO AIRPORT 153.55 INCHES (154 PERCENT OF NORMAL)
THE NCEP CLIMATE FORECAST SYSTEM (CFS) AND OTHER CLIMATE MODELS, RUN AS A PART 
OF THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME), PREDICT ABOVE NORMAL SSTS 
AROUND THE HAWAIIAN ISLANDS FOR DECEMBER 2018. THIS INCREASES THE CHANCES OF 
ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR HAWAII IN DECEMBER 2018. MOST 
DYNAMICAL MODELS PREDICT BELOW NORMAL PRECIPITATION OVER AREAS NEAR THE 
NORTHWESTERN HAWAIIAN ISLANDS WITH GREATER UNCERTAINTY AMONG FORECASTS FOR MOST 
OTHER AREAS OF THE HAWAIIAN ISLANDS DURING DECEMBER 2018.
           TEMPERATURE           PRECIPITATION
          FCST   AVE    LIM  FCST  BLW  MEDIAN  ABV
HILO       A65   72.5   0.4   EC   6.8   10.2   13.6
KAHULUI    A65   73.5   0.5   EC   1.9   2.7   3.4
HONOLULU   A60   74.9   0.6  B45   0.8   1.3   3.8
LIHUE      A60   73.3   0.5  B45   1.8   3.2   5.5
SEASONAL FORECAST DISCUSSION VALID DJF 2018 - DJF 2019
REFER TO THE PROGNOSTIC DISCUSSION ON LONG-LEAD SEASONAL OUTLOOKS FOR THE CONUS 
AND ALASKA FOR A DISCUSSION OF THE ENSO FORECAST AND CLIMATE CONDITIONS 
RELEVANT TO THE SEASONAL OUTLOOK, INCLUDING DETAILS ON THE CURRENT STATE OF THE 
ATMOSPHERE AND OCEAN. ENSO-NEUTRAL CONDITIONS CURRENTLY ARE PRESENT ACROSS THE 
EQUATORIAL PACIFIC OCEAN. EQUATORIAL SEA SURFACE TEMPERATURES (SSTS) ARE ABOVE 
AVERAGE ACROSS THE PACIFIC OCEAN. POSITIVE SUBSURFACE TEMPERATURE ANOMALIES 
HAVE STRENGTHENED AND EXPANDED INTO THE EASTERN PACIFIC OCEAN.  CONVECTION IS 
ANOMALOUSLY BELOW AVERAGE OVER THE DATE LINE. LOW-LEVEL WESTERLY WIND ANOMALIES 
ARE OBSERVED OVER THE EASTERN PACIFIC, WHILE WEAK UPPER-LEVEL WESTERLY WIND 
ANOMALIES ARE PRESENT OVER THE FAR WESTERN PACIFIC. THE OFFICIAL CONSENSUS ENSO 
FORECAST INDICATES ABOUT 80% PROBABILITY OF EL NINO ONSET THROUGH THE NORTHERN 
HEMISPHERE WINTER 2018, AND ABOUT 55-60% CHANCE INTO SPRING 2019. 
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HAWAII 
FROM DJF 2019 TO MJJ 2019 DUE TO PREDICTED ABOVE NORMAL SEA SURFACE 
TEMPERATURES ACROSS THE REGION. EQUAL CHANCES (EC) FOR ABOVE, NEAR, OR BELOW 
NORMAL TEMPERATURES ARE INDICATED AT ALL LOCATIONS OF THE HAWAII FORECAST FOR 
JJA 2019 AND BEYOND, DUE TO INCREASING UNCERTAINTY IN CLIMATE CONDITIONS AT 
LONGER LEAD TIMES.
MOST ENSO FORECAST MODELS PREDICT A WARM EVENT, OR EL NINO, DEVELOPING IN THE 
NORTHERN HEMISPHERE AUTUMN OR WINTER 2018-19. HISTORICAL EL NINO IMPACTS 
INDICATE STRONG CORRELATIONS BETWEEN EL NINO AND INCREASED PROBABILITIES OF 
BELOW NORMAL PRECIPITATION FOR HAWAII IN WINTER AND SPRING, CONSISTENT WITH 
NMME DYNAMICAL MODEL FORECASTS AND STATISTICAL TOOLS, INCLUDING THE CONSTRUCTED 
ANALOG AND THE ENSO-OCN TOOL, INDICATING THE COMBINED IMPACT OF EL NINO AND 
DECADAL CLIMATE VARIABILITY. INCREASED PROBABILITIES OF BELOW NORMAL 
PRECIPITATION ARE FAVORED FOR THE HAWAIIAN ISLANDS FROM DJF TO MJJ 2019. THERE 
IS CONSIDERABLE UNCERTAINTY ACROSS THE HAWAIIAN ISLANDS IN THE PRECIPITATION 
FORECAST AMONG AVAILABLE FORECAST TOOLS IN JJA 2019 AND LONGER LEADS, SO EQUAL 
CHANCES (EC) FOR ABOVE, NEAR, OR BELOW NORMAL PRECIPITATION ARE INDICATED.
                      HILO
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
DJF 2019  A65  72.8   0.4   B65   19.6   30.2   33.3
JFM 2019  A60  71.8   0.4   B70   22.0   32.0   44.5
FMA 2019  A60  71.7   0.4   B65   24.6   34.1   45.5
MAM 2019  A55  72.0   0.5   B65   22.5   28.4   34.0
AMJ 2019  A45  72.9   0.5   B60   21.4   23.7   29.0
MJJ 2019  A40  74.0   0.4   B50   20.2   27.5   29.1
JJA 2019   EC  75.2   0.4    EC   19.4   27.2   31.4
JAS 2019   EC  76.1   0.4    EC   25.2   28.6   33.4
ASO 2019   EC  76.4   0.4    EC   26.1   28.8   33.3
SON 2019   EC  76.2   0.4    EC   24.3   30.2   40.8
OND 2019   EC  75.5   0.4    EC   28.3   34.5   42.0
NDJ 2019   EC  74.2   0.4    EC   26.4   36.6   43.0
DJF 2020   EC  72.8   0.4    EC   19.6   30.2   33.3
                      KAHULUI
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
DJF 2019  A65  73.8   0.4   B65   4.6    6.9    8.7 
JFM 2019  A60  72.5   0.4   B70   4.2    6.2    8.2 
FMA 2019  A60  72.3   0.4   B65   3.2    4.1    6.4 
MAM 2019  A55  73.0   0.4   B65   2.5    3.5    4.6 
AMJ 2019  A45  74.3   0.5   B60   1.2    1.6    2.2 
MJJ 2019  A40  76.0   0.5   B50   0.7    1.1    1.8 
JJA 2019   EC  77.7   0.4    EC   0.7    1.1    1.5 
JAS 2019   EC  79.0   0.4    EC   0.8    1.1    1.6 
ASO 2019   EC  79.4   0.4    EC   0.8    1.6    2.5 
SON 2019   EC  79.1   0.4    EC   2.1    3.3    4.8 
OND 2019   EC  77.8   0.4    EC   4.2    5.3    8.1 
NDJ 2019   EC  75.9   0.4    EC   5.2    7.6    9.5 
DJF 2020   EC  73.8   0.4    EC   4.6    6.9    8.7 
                      HONOLULU
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
DJF 2019  A60  75.3   0.5   B65   3.7    5.6    8.6 
JFM 2019  A55  73.9   0.4   B70   2.1    4.6    7.8 
FMA 2019  A55  73.8   0.4   B65   1.9    3.2    4.7 
MAM 2019  A50  74.8   0.4   B65   1.8    2.6    3.0 
AMJ 2019  A45  76.3   0.4   B60   1.2    1.6    1.8 
MJJ 2019  A40  78.2   0.4   B50   0.8    1.4    1.6 
JJA 2019   EC  79.9   0.4    EC   0.7    0.8    1.3 
JAS 2019   EC  81.3   0.4    EC   1.0    1.4    1.7 
ASO 2019   EC  81.7   0.4    EC   1.6    2.4    3.1 
SON 2019   EC  81.4   0.4    EC   2.5    4.0    5.6 
OND 2019   EC  80.0   0.4    EC   4.4    6.4    8.5 
NDJ 2019   EC  77.7   0.5    EC   3.9    5.6    8.8 
DJF 2020   EC  75.3   0.5    EC   3.7    5.6    8.6 
                      LIHUE
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
DJF 2019  A55  73.6   0.4   B65   7.5    8.4    14.0
JFM 2019  A50  72.2   0.4   B70   6.5    8.8    13.8
FMA 2019  A50  72.1   0.5   B65   5.8    8.4    9.9 
MAM 2019  A45  72.8   0.5   B65   5.3    6.6    8.0 
AMJ 2019  A40  74.2   0.5   B60   4.7    5.5    6.0 
MJJ 2019  A40  76.0   0.5   B50   4.9    5.4    5.9 
JJA 2019   EC  77.7   0.4    EC   4.4    5.3    6.9 
JAS 2019   EC  79.0   0.3    EC   5.3    6.1    7.8 
ASO 2019   EC  79.4   0.3    EC   6.2    7.9    8.4 
SON 2019   EC  79.1   0.3    EC   9.2    10.0   11.2
OND 2019   EC  77.8   0.3    EC   9.2    11.7   15.6
NDJ 2019   EC  75.7   0.3    EC   8.6    12.1   16.9
DJF 2020   EC  73.6   0.4    EC   7.5    8.4    14.0
FORECASTER: LUKE HE
ANOMALIES ARE BASED ON THE 1981-2010 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 DEC 20, 2018.
$$