Hawaii 30 & 90 Day Narrative

718 
FXHW40 KWBC 191231
PMDHCO
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830AM EDT THU SEP 19 2013
MONTHLY FORECAST DISCUSSION VALID OCTOBER 2013
SST ANOMALIES NEAR HAWAII ARE NEAR +0.5 DEGREES C NEAR THE NORTHWESTERN 
ISLANDS, AND SLIGHTLY LOWER, BUT REMAINING POSITIVE NEAR THE BIG ISLAND. 
 
FOR JANUARY 2013 THROUGH THE END OF AUGUST, RAINFALL TOTAL ACCUMULATIONS WERE: 
 
- LIHUE AIRPORT 17.21 INCHES (80 PERCENT OF NORMAL) 
- HONOLULU AIRPORT 9.08 INCHES (102 PERCENT OF NORMAL) 
- KAHULUI AIRPORT 8.66 INCHES (81 PERCENT OF NORMAL) 
- HILO AIRPORT 54.88 INCHES (81 PERCENT OF NORMAL) 
 
THE CFS SHOWS WEAK INDICATIONS FOR ABOVE NORMAL TEMPERATURES FOR HAWAII. SST 
ANOMALIES ARE FORECAST BY THE CFS TO EDGE UPWARD TO AROUND +0.5 DEGREES C IN 
OCTOBER. CLIMATE MODELS RUN AS A PART OF THE NATIONAL MULTI-MODEL ENSEMBLE 
(NMME) ALSO SUPPORT THIS FORECAST SO THE CHANCES OF ABOVE NORMAL TEMPERATURES 
ARE SLIGHTLY ENHANCED FOR OCTOBER, 2013.  THERE IS CONSIDERABLE VARIABILITY IN 
THE PRECIPITATION FORECAST BETWEEN MODELS INCLUDED IN THE NMME.  BELOW MEDIAN 
PRECIPITATION IS SLIGHTLY FAVORED AMONG MEMBERS, LEADING TO A FORECAST OF 
SLIGHT ELEVATED CHANCES FOR BELOW MEDIAN PRECIPITATION AMOUNTS FOR HAWAII IN 
OCTOBER 2013.
           TEMPERATURE           PRECIPITATION
          FCST   AVE    LIM  FCST  BLW  MEDIAN  ABV
HILO       A40   75.7   0.5  B40   7.8   8.6   12.1
KAHULUI    A40   78.2   0.4  B40   0.3   0.6   1.1
HONOLULU   A40   80.2   0.5  B40   0.5   1.3   1.9
LIHUE      A40   78.1   0.3  B40   2.5   3.3   4.2
SEASONAL FORECAST DISCUSSION VALID OND 2013 - OND 2014
REFER TO THE 90 DAY DISCUSSION FOR FORECASTS OF EQUATORIAL PACIFIC SST AND 
DETAILS OF THE GENERAL BACKGROUND TO THE FORECAST. ENSO-NEUTRAL CONDITIONS 
CONTINUE ACROSS THE EQUATORIAL PACIFIC. SEA SURFACE TEMPERATURE ANOMALIES HAVE 
RISEN SLIGHTLY IN THE LAST FEW WEEKS IN THE CENTRAL PACIFIC AND ARE NOW VERY 
SLIGHTLY POSITIVE. BELOW NORMAL EQUATORIAL SSTS ARE HOLDING ON IN MUCH OF THE 
EASTERN PACIFIC ALTHOUGH BELOW NORMAL WATER TEMPERATURES ALONG THE EQUATOR ARE 
CONFINED TO A SHALLOW LAYER NEAR THE SURFACE THROUGHOUT THE EASTERN PACIFIC 
EXCEPT NEAR THE SOUTH AMERICAN COAST. WINDS AT BOTH LOW AND UPPER LEVELS WERE 
CLOSE TO LONG TERM AVERAGES IN AUGUST. CONVECTION REMAINED ENHANCED OVER 
INDONESIA AND SUPPRESSED IN THE CENTRAL PART OF THE BASIN. MOST MODEL FORECASTS 
INDICATE THAT SSTS THROUGHOUT THE EAST-CENTRAL EQUATORIAL PACIFIC WILL REMAIN 
CLOSE TO NORMAL THROUGH AT LEAST EARLY 2014, FAVORING CONTINUED ENSO-NEUTRAL 
CONDITIONS.
THE CFS AND NMME SHOW ONLY VERY WEAK INDICATIONS OF CLIMATE ANOMALIES FOR THE 
NORTHERN HEMISPHERE FALL AND WINTER. BOTH THE CFS AND NMME PREDICT CONTINUED 
POSITIVE SST ANOMALIES NEAR HAWAII FOR OND, WITH MAGNITUDES STRONGEST NEAR THE 
NORTHWESTERN ISLANDS, LEADING TO ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES 
FOR LIHUE AND HONOLULU FOR OND 2013. THERE ARE NO CLEAR INDICATIONS FOR 
TEMPERATURE ANOMALIES BEYOND OND, SO EQUAL CHANCES FOR ABOVE, NEAR OR BELOW 
NORMAL TEMPERATURES ARE ANTICIPATED AT ALL LOCATIONS FOR LEAD TIMES BEYOND OND 
2013. 
THE NMME SHOWS ENHANCED CHANCES FOR BELOW MEDIAN PRECIPITATION JUST SOUTH OF 
HAWAII FOR OND 2013. SOME HINTS AT DRY CONDITIONS FROM FORECASTS BASED ON SST 
CONSTRUCTED ANALOGS AND INDICATIONS FOR BELOW MEDIAN PRECIPITATION FROM THE CCA 
LEAD TO A FORECAST FOR ELEVATED CHANCES OF BELOW MEDIAN PRECIPITATION AT HILO.  
THE PROBABILISTIC FORECAST FROM THE NMME INDICATES ELEVATED CHANCES FOR BELOW 
MEDIAN PRECIPITATION FOR JFM AND FMA 2014, WITH STATISTICAL FORECASTS FROM CCA 
EXTENDING THIS SIGNAL INTO MAM 2014 AT HILO.   
                      HILO
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
OND 2013   EC  75.5   0.4   B40   28.3   34.5   42.0
NDJ 2013   EC  74.2   0.4    EC   26.4   36.6   43.0
DJF 2014   EC  72.8   0.4    EC   19.6   30.2   33.3
JFM 2014   EC  71.8   0.4   B40   22.0   32.0   44.5
FMA 2014   EC  71.7   0.4   B40   24.6   34.1   45.5
MAM 2014   EC  72.0   0.5   B40   22.5   28.4   34.0
AMJ 2014   EC  72.9   0.5    EC   21.4   23.7   29.0
MJJ 2014   EC  74.0   0.4    EC   20.2   27.5   29.1
JJA 2014   EC  75.2   0.4    EC   19.4   27.2   31.4
JAS 2014   EC  76.1   0.4    EC   25.2   28.6   33.4
ASO 2014   EC  76.4   0.4    EC   26.1   28.8   33.3
SON 2014   EC  76.2   0.4    EC   24.3   30.2   40.8
OND 2014   EC  75.5   0.4    EC   28.3   34.5   42.0
                      KAHULUI
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
OND 2013   EC  77.8   0.4    EC   4.2    5.3    8.1 
NDJ 2013   EC  75.9   0.4    EC   5.2    7.6    9.5 
DJF 2014   EC  73.8   0.4    EC   4.6    6.9    8.7 
JFM 2014   EC  72.5   0.4   B40   4.2    6.2    8.2 
FMA 2014   EC  72.3   0.4   B40   3.2    4.1    6.4 
MAM 2014   EC  73.0   0.4    EC   2.5    3.5    4.6 
AMJ 2014   EC  74.3   0.5    EC   1.2    1.6    2.2 
MJJ 2014   EC  76.0   0.5    EC   0.7    1.1    1.8 
JJA 2014   EC  77.7   0.4    EC   0.7    1.1    1.5 
JAS 2014   EC  79.0   0.4    EC   0.8    1.1    1.6 
ASO 2014   EC  79.4   0.4    EC   0.8    1.6    2.5 
SON 2014   EC  79.1   0.4    EC   2.1    3.3    4.8 
OND 2014   EC  77.8   0.4    EC   4.2    5.3    8.1 
                      HONOLULU
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
OND 2013  A40  80.0   0.4    EC   4.4    6.4    8.5 
NDJ 2013   EC  77.7   0.5    EC   3.9    5.6    8.8 
DJF 2014   EC  75.3   0.5    EC   3.7    5.6    8.6 
JFM 2014   EC  73.9   0.4   B40   2.1    4.6    7.8 
FMA 2014   EC  73.8   0.4   B40   1.9    3.2    4.7 
MAM 2014   EC  74.8   0.4    EC   1.8    2.6    3.0 
AMJ 2014   EC  76.3   0.4    EC   1.2    1.6    1.8 
MJJ 2014   EC  78.2   0.4    EC   0.8    1.4    1.6 
JJA 2014   EC  79.9   0.4    EC   0.7    0.8    1.3 
JAS 2014   EC  81.3   0.4    EC   1.0    1.4    1.7 
ASO 2014   EC  81.7   0.4    EC   1.6    2.4    3.1 
SON 2014   EC  81.4   0.4    EC   2.5    4.0    5.6 
OND 2014   EC  80.0   0.4    EC   4.4    6.4    8.5 
                      LIHUE
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
OND 2013  A40  77.8   0.3    EC   9.2    11.7   15.6
NDJ 2013   EC  75.7   0.3    EC   8.6    12.1   16.9
DJF 2014   EC  73.6   0.4    EC   7.5    8.4    14.0
JFM 2014   EC  72.2   0.4   B40   6.5    8.8    13.8
FMA 2014   EC  72.1   0.5   B40   5.8    8.4    9.9 
MAM 2014   EC  72.8   0.5    EC   5.3    6.6    8.0 
AMJ 2014   EC  74.2   0.5    EC   4.7    5.5    6.0 
MJJ 2014   EC  76.0   0.5    EC   4.9    5.4    5.9 
JJA 2014   EC  77.7   0.4    EC   4.4    5.3    6.9 
JAS 2014   EC  79.0   0.3    EC   5.3    6.1    7.8 
ASO 2014   EC  79.4   0.3    EC   6.2    7.9    8.4 
SON 2014   EC  79.1   0.3    EC   9.2    10.0   11.2
OND 2014   EC  77.8   0.3    EC   9.2    11.7   15.6
FORECASTER: DAVID UNGER
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 -A37 MEANS A 37% CHANCE THAT TEMPERATURE OR PRECIPITATION WILL BE 
IN THE ABOVE CLASS - B36 MEANS A 36% 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 THE PROBABILITY OF THE MOST LIKELY CATEGORY CANNOT BE PREDICTED.
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 OCT 17, 2013.