Climate Prediction Center - Seasonal Outlook

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.
 
 
$$