Hawaii 30 & 90 Day Narrative

865 
FXHW40 KWBC 171231
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THU MAY 17 2018
MONTHLY FORECAST DISCUSSION VALID JUNE 2018
SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO NEGATIVE 
ONE-HALF DEGREE C OVER THE NORTHERN HAWAIIAN ISLANDS, AND ABOUT POSITIVE 
ONE-HALF TO ONE DEGREE C OVER THE SOUTHEASTERN ISLANDS. 
FOR JANUARY 2018 THROUGH THE END OF APRIL 2018, RAINFALL TOTAL ACCUMULATIONS 
WERE:
- LIHUE AIRPORT 24.34 INCHES (177 PERCENT OF NORMAL)
- HONOLULU AIRPORT 7.94 INCHES (114 PERCENT OF NORMAL)
- KAHULUI AIRPORT 12.51 INCHES (143 PERCENT OF NORMAL)
- HILO AIRPORT 54.26 INCHES (124 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 JUNE 2018. THIS ELEVATES THE 
CHANCES OF ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR KAHULUI AND HILO IN 
JUNE 2018. BELOW NORMAL TEMPERATURES ARE FAVORED FOR LIHUE WHERE SSTS ARE 
CURRENTLY BELOW NORMAL. MOST DYNAMICAL TOOLS ALSO FAVOR ABOVE NORMAL 
PRECIPITATION FOR THE SOUTHEASTERN ISLANDS (HILO AND KAHULUI) DURING JUNE 2018.
           TEMPERATURE           PRECIPITATION
          FCST   AVE    LIM  FCST  BLW  MEDIAN  ABV
HILO       A60   75.4   0.4  A50   5.3   6.3   8.7
KAHULUI    A50   78.0   0.5  A40   0.1   0.1   0.2
HONOLULU    EC   80.3   0.4   EC   0.1   0.2   0.3
LIHUE      B40   78.1   0.4   EC   1.1   1.3   1.6
SEASONAL FORECAST DISCUSSION VALID JJA 2018 - JJA 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-BELOW AVERAGE ACROSS THE EAST-CENTRAL AND 
EASTERN PACIFIC OCEAN, AND ABOVE AVERAGE IN THE WESTERN PACIFIC. POSITIVE 
SUBSURFACE TEMPERATURE ANOMALIES HAVE SHIFTED EASTWARD INTO THE EASTERN PACIFIC 
OCEAN,WHILE NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES HAVE WEAKENED IN 
THE FAR EASTERN PACIFIC OCEAN. CONVECTION WAS REMAINED SUPPRESSED NEAR AND EAST 
OF THE DATE LINE, WHILE LOW-LEVEL WIND ANOMALIES WERE NEAR AVERAGE OVER MOST OF 
THE TROPICAL PACIFIC OCEAN AND UPPER-LEVEL WINDS WERE ANOMALOUS WESTERLY OVER 
THE EASTERN PACIFIC. MOST MODELS INDICATE ENSO-NEUTRAL TO CONTINUE AT LEAST 
THROUGH THE NORTHERN HEMISPHERE SUMMER 2018, WITH THE POSSIBILITY OF EL NINO 
NEARING 50% BY NORTHERN HEMISPHERE WINTER 2018-19.
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HONOLULU 
AND LIHUE FROM JAS TO NDJ, 2018. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR 
HILO AND KAHULUI FROM JJA 2018 TO NDJ 2018 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 DJF 2019 AND 
BEYOND.
DYNAMICAL TOOLS AND CONSTRUCTED ANALOG TOOL FAVOR ABOVE NORMAL PRECIPITATION 
FOR HAWAII FROM JJA TO ASO, 2018. THE STATISTICAL TOOLS (CANONICAL CORRELATION 
ANALYSIS, AND ENSO-OCN) PREDICT BELOW NORMAL PRECIPITATION DURING THE SUMMER. 
THEREFORE THE PROBABILITIES OF ABOVE NORMAL PRECIPITATION ARE LOWERED. SOME 
ENSO FORECAST MODELS PREDICT A WARM EVENT (EL NINO) BY THE NORTHERN HEMISPHERE 
WINTER 2018-19. IF CORRECT, HISTORICAL EL NINO COMPOSITES FAVOR INCREASED ODDS 
FOR DRY CONDITIONS FOR HAWAII IN WINTER, WHICH IS CONSISTENT WITH THE FORECAST 
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 FROM SON TO OND 2018, 
AND  IN JFM 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
JJA 2018  A65  75.2   0.4   A50   19.4   27.2   31.4
JAS 2018  A60  76.1   0.4   A45   25.2   28.6   33.4
ASO 2018  A55  76.4   0.4   A40   26.1   28.8   33.3
SON 2018  A50  76.2   0.4    EC   24.3   30.2   40.8
OND 2018  A45  75.5   0.4    EC   28.3   34.5   42.0
NDJ 2018  A40  74.2   0.4   B40   26.4   36.6   43.0
DJF 2019   EC  72.8   0.4   B40   19.6   30.2   33.3
JFM 2019   EC  71.8   0.4    EC   22.0   32.0   44.5
FMA 2019   EC  71.7   0.4    EC   24.6   34.1   45.5
MAM 2019   EC  72.0   0.5    EC   22.5   28.4   34.0
AMJ 2019   EC  72.9   0.5    EC   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
\N                      KAHULUI
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JJA 2018  A65  77.7   0.4   A50   0.7    1.1    1.5 
JAS 2018  A60  79.0   0.4   A45   0.8    1.1    1.6 
ASO 2018  A55  79.4   0.4   A40   0.8    1.6    2.5 
SON 2018  A50  79.1   0.4    EC   2.1    3.3    4.8 
OND 2018  A45  77.8   0.4    EC   4.2    5.3    8.1 
NDJ 2018  A40  75.9   0.4   B40   5.2    7.6    9.5 
DJF 2019   EC  73.8   0.4   B40   4.6    6.9    8.7 
JFM 2019   EC  72.5   0.4    EC   4.2    6.2    8.2 
FMA 2019   EC  72.3   0.4    EC   3.2    4.1    6.4 
MAM 2019   EC  73.0   0.4    EC   2.5    3.5    4.6 
AMJ 2019   EC  74.3   0.5    EC   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 
\N                      HONOLULU
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JJA 2018   EC  79.9   0.4   A50   0.7    0.8    1.3 
JAS 2018  A55  81.3   0.4   A45   1.0    1.4    1.7 
ASO 2018  A55  81.7   0.4   A40   1.6    2.4    3.1 
SON 2018  A50  81.4   0.4    EC   2.5    4.0    5.6 
OND 2018  A45  80.0   0.4    EC   4.4    6.4    8.5 
NDJ 2018  A40  77.7   0.5   B40   3.9    5.6    8.8 
DJF 2019   EC  75.3   0.5   B40   3.7    5.6    8.6 
JFM 2019   EC  73.9   0.4    EC   2.1    4.6    7.8 
FMA 2019   EC  73.8   0.4    EC   1.9    3.2    4.7 
MAM 2019   EC  74.8   0.4    EC   1.8    2.6    3.0 
AMJ 2019   EC  76.3   0.4    EC   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 
\N                      LIHUE
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JJA 2018   EC  77.7   0.4   A50   4.4    5.3    6.9 
JAS 2018  A55  79.0   0.3   A45   5.3    6.1    7.8 
ASO 2018  A55  79.4   0.3   A40   6.2    7.9    8.4 
SON 2018  A50  79.1   0.3    EC   9.2    10.0   11.2
OND 2018  A45  77.8   0.3    EC   9.2    11.7   15.6
NDJ 2018  A40  75.7   0.3   B40   8.6    12.1   16.9
DJF 2019   EC  73.6   0.4   B40   7.5    8.4    14.0
JFM 2019   EC  72.2   0.4    EC   6.5    8.8    13.8
FMA 2019   EC  72.1   0.5    EC   5.8    8.4    9.9 
MAM 2019   EC  72.8   0.5    EC   5.3    6.6    8.0 
AMJ 2019   EC  74.2   0.5    EC   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 
\NFORECASTER: LUKE HE
ANOMALIES BASED ON 1981-2010 MEANS
 CLARIFICATION: EC INDICATES EQUAL CHANCES THAT THE CLIMATE WILL FALL INTO ANY 
ONE OF THE THREE RANGES OR CATEGORIES WHOSE BOUNDARIES ARE SPECIFIED IN THE 
TABLES ABOVE. A FORECAST SPECIFICATION OF EC MEANS THERE IS NO PARTICULAR TILT 
OF THE ODDS TOWARD ABOVE-NORMAL OR BELOW-NORMAL CONDITIONS IN THE OUTLOOK. FOR 
EXAMPLE A40 MEANS A 40% CHANCE THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE 
ABOVE CLASS, B40 MEANS A 40% PROBABILITY THAT TEMPERATURE OR PRECIPITATION WILL 
BE IN THE BELOW CLASS, AND N35 MEANS A 35% PROBABILITY THAT TEMPERATURE OR 
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 THEIR VALID 
PERIODS.  WITHIN ANY VALID PERIOD OBSERVATIONS AND SHORTER RANGE FORECASTS 
SHOULD BE CONSULTED.  ALSO - THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE 
ISSUANCE OF THE NEW SET NEXT MONTH ON THU JUN 21, 2018.
$$