Hawaii 30 & 90 Day Narrative

325 
FXHW40 KWBC 161231
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THU AUG 16 2018
MONTHLY FORECAST DISCUSSION VALID SEPTEMBER 2018
SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO POSITIVE 
ONE-HALF DEGREE C NEAR THE HAWAIIAN ISLANDS.
FOR JANUARY 2018 THROUGH THE END OF JULY 2018, RAINFALL TOTAL ACCUMULATIONS 
WERE:
- LIHUE AIRPORT 29.02 INCHES (150 PERCENT OF NORMAL)
- HONOLULU AIRPORT 8.57 INCHES (103 PERCENT OF NORMAL)
- KAHULUI AIRPORT 13.98 INCHES (137 PERCENT OF NORMAL)
- HILO AIRPORT 80.96 INCHES (116 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 SOUTHEASTERN HAWAIIAN ISLANDS FOR SEPTEMBER 2018. THIS ELEVATES THE 
CHANCES OF ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR HAWAII IN SEPTEMBER 
2018. MOST DYNAMICAL TOOLS ALSO FAVOR ABOVE NORMAL PRECIPITATION FOR THE 
HAWAIIAN ISLANDS DURING SEPTEMBER 2018.
           TEMPERATURE           PRECIPITATION
          FCST   AVE    LIM  FCST  BLW  MEDIAN  ABV
HILO       A65   76.4   0.5  A50   8.0   9.3   11.0
KAHULUI    A60   79.3   0.4  A50   0.1   0.2   0.5
HONOLULU   A60   81.8   0.4  A50   0.4   0.6   0.8
LIHUE      A55   79.4   0.3  A50   1.7   1.9   2.6
SEASONAL FORECAST DISCUSSION VALID SON 2018 - SON 2019
REFER TO THE PROGNOSTIC DISCUSSION ON LONG-LEAD SEASONAL OUTLOOKS FOR THE CONUS 
AND ALASKA FOR A DISCUSSION OF THE FORECASTS OF EQUATORIAL PACIFIC SSTS, AND 
FOR THE GENERAL BACKGROUND FOR THE SEASONAL FORECAST, 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 NEAR-TO-ABOVE AVERAGE ACROSS MOST OF THE PACIFIC OCEAN. 
POSITIVE SUBSURFACE TEMPERATURE ANOMALIES EXTENDED TO THE SURFACE IN THE 
EASTERN PACIFIC OCEAN. CONVECTION REMAINED SUPPRESSED NEAR THE DATE LINE. 
ANOMALOUS LOW-LEVEL WESTERLY WINDS WERE EVIDENT OVER THE EAST-CENTRAL TROPICAL 
PACIFIC OCEAN, WHILE UPPER-LEVEL WINDS WERE NEAR AVERAGE OVER THE EASTERN 
PACIFIC OCEAN AND NEAR THE INTERNATIONAL DATE LINE. MOST MODELS INDICATE 
ENSO-NEUTRAL TO CONTINUE AT LEAST THROUGH THE NORTHERN HEMISPHERE SUMMER 2018, 
WITH THE PROBABILITY OF EL NINO NEARING 60% DURING THE NORTHERN HEMISPHERE 
AUTUMN, INCREASING TO ABOUT 70% BY NORTHERN HEMISPHERE WINTER 2018-19. 
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HAWAII 
FROM SON 2018 TO FMA 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 FOR MAM 2019 AND BEYOND.
DYNAMICAL TOOLS FAVOR ABOVE NORMAL PRECIPITATION FOR HAWAII IN SON 2018. MOST 
ENSO FORECAST MODELS PREDICT A WARM EVENT (EL NINO) BY THE NORTHERN HEMISPHERE 
AUTUMN OR WINTER 2018-19. IF CORRECT, HISTORICAL EL NINO COMPOSITES FAVOR 
INCREASED ODDS FOR DRY CONDITIONS FOR HAWAII IN WINTER AND SPRING , WHICH IS 
CONSISTENT WITH THE FORECASTS FROM THE STATISTICAL TOOLS (CONSTRUCTED ANALOG, 
CANONICAL CORRELATION ANALYSIS, AND ENSO-OCN). THERE IS CONSIDERABLE 
UNCERTAINTY ACROSS THE HAWAIIAN ISLANDS IN THE PRECIPITATION FORECAST AMONG 
AVAILABLE FORECAST TOOLS IN OND 2018, AND IN MJJ 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
SON 2018  A65  76.2   0.4   A40   24.3   30.2   40.8
OND 2018  A65  75.5   0.4    EC   28.3   34.5   42.0
NDJ 2018  A60  74.2   0.4   B55   26.4   36.6   43.0
DJF 2019  A60  72.8   0.4   B65   19.6   30.2   33.3
JFM 2019  A50  71.8   0.4   B65   22.0   32.0   44.5
FMA 2019  A40  71.7   0.4   B60   24.6   34.1   45.5
MAM 2019   EC  72.0   0.5   B50   22.5   28.4   34.0
AMJ 2019   EC  72.9   0.5   B40   21.4   23.7   29.0
MJJ 2019   EC  74.0   0.4    EC   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
                      KAHULUI
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
SON 2018  A65  79.1   0.4   A40   2.1    3.3    4.8 
OND 2018  A65  77.8   0.4    EC   4.2    5.3    8.1 
NDJ 2018  A60  75.9   0.4   B55   5.2    7.6    9.5 
DJF 2019  A60  73.8   0.4   B65   4.6    6.9    8.7 
JFM 2019  A50  72.5   0.4   B65   4.2    6.2    8.2 
FMA 2019  A40  72.3   0.4   B60   3.2    4.1    6.4 
MAM 2019   EC  73.0   0.4   B50   2.5    3.5    4.6 
AMJ 2019   EC  74.3   0.5   B40   1.2    1.6    2.2 
MJJ 2019   EC  76.0   0.5    EC   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 
                      HONOLULU
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
SON 2018  A60  81.4   0.4   A40   2.5    4.0    5.6 
OND 2018  A60  80.0   0.4    EC   4.4    6.4    8.5 
NDJ 2018  A55  77.7   0.5   B55   3.9    5.6    8.8 
DJF 2019  A55  75.3   0.5   B65   3.7    5.6    8.6 
JFM 2019  A45  73.9   0.4   B65   2.1    4.6    7.8 
FMA 2019  A40  73.8   0.4   B60   1.9    3.2    4.7 
MAM 2019   EC  74.8   0.4   B50   1.8    2.6    3.0 
AMJ 2019   EC  76.3   0.4   B40   1.2    1.6    1.8 
MJJ 2019   EC  78.2   0.4    EC   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 
                      LIHUE
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
SON 2018  A55  79.1   0.3   A40   9.2    10.0   11.2
OND 2018  A55  77.8   0.3    EC   9.2    11.7   15.6
NDJ 2018  A50  75.7   0.3   B55   8.6    12.1   16.9
DJF 2019  A50  73.6   0.4   B65   7.5    8.4    14.0
JFM 2019  A45  72.2   0.4   B65   6.5    8.8    13.8
FMA 2019  A40  72.1   0.5   B60   5.8    8.4    9.9 
MAM 2019   EC  72.8   0.5   B60   5.3    6.6    8.0 
AMJ 2019   EC  74.2   0.5   B40   4.7    5.5    6.0 
MJJ 2019   EC  76.0   0.5    EC   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
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 SEP 20, 2018.
$$