085  
FXHW40 KWBC 181231  
PMDHCO  
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
830AM EDT THU OCT 18 2018  
 
MONTHLY FORECAST DISCUSSION VALID NOVEMBER 2018  
 
SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO POSITIVE  
ONE HALF DEGREE C OVER THE NORTHWESTERN HAWAIIAN ISLANDS, AND ABOUT POSITIVE  
ONE-HALF DEGREE TO POSITIVE ONE DEGREE C OVER THE SOUTHEASTERN ISLANDS.  
 
FOR JANUARY 2018 THROUGH THE END OF SEPTEMBER 2018, RAINFALL TOTAL  
ACCUMULATIONS WERE:  
 
- LIHUE AIRPORT 39.16 INCHES (166 PERCENT OF NORMAL)  
 
- HONOLULU AIRPORT 11.37 INCHES (118 PERCENT OF NORMAL)  
 
- KAHULUI AIRPORT 17.88 INCHES (161 PERCENT OF NORMAL)  
 
- HILO AIRPORT 135.32 INCHES (151 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 NOVEMBER 2018. THIS INCREASES THE CHANCES OF  
ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR HAWAII IN NOVEMBER 2018. MOST  
DYNAMICAL MODELS PREDICT ABOVE NORMAL PRECIPITATION OVER AREAS NEAR THE  
SOUTHEASTERN HAWAIIAN ISLANDS WITH GREATER UNCERTAINTY AMONG FORECASTS FOR MOST  
OTHER AREAS OF THE HAWAIIAN ISLANDS DURING NOVEMBER 2018.  
 
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
HILO A65 74.4 0.4 A45 8.7 11.4 17.1  
KAHULUI A65 76.0 0.6 EC 1.2 1.8 2.6  
HONOLULU A60 77.8 0.6 EC 0.9 1.4 2.1  
LIHUE A60 75.8 0.5 EC 2.6 3.5 5.5  
 
SEASONAL FORECAST DISCUSSION VALID NDJ 2018 - NDJ 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 IN MOST OF THE CENTRAL AND EASTERN PACIFIC OCEAN. POSITIVE SUBSURFACE  
TEMPERATURE ANOMALIES HAVE INCREASED AND EXPANDED ACROSS THE CENTRAL AND  
EAST-CENTRAL PACIFIC OCEAN. CONVECTION IS ANOMALOUSLY BELOW AVERAGE OVER THE  
DATE LINE. LOW-LEVEL WESTERLY WIND ANOMALIES ARE PRESENT NORTH OF THE EQUATOR  
OVER THE EAST-CENTRAL TROPICAL PACIFIC OCEAN, WHILE UPPER-LEVEL WIND ANOMALIES  
ARE EASTERLY OVER A SMALL AREA OF THE EAST-CENTRAL PACIFIC OCEAN. THE OFFICIAL  
CONSENSUS ENSO FORECAST INDICATES OVER A 50% PROBABILITY OF EL NINO ONSET  
DURING THE NORTHERN HEMISPHERE AUTUMN 2018, INCREASING TO OVER A 70% CHANCE  
DURING WINTER 2018-19.  
 
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HAWAII  
FROM NDJ 2018 TO AMJ 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  
MJJ 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. EARLY IN THE NDJ SEASON, DYNAMICAL MODEL FORECASTS  
INDICATE INCREASED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR THE  
SOUTHEASTERN HAWAIIAN ISLANDS, MODERATING THE PROBABILITIES FOR BELOW NORMAL  
PRECIPITATION TOTALS FOR THE ENTIRE SEASON. THERE IS CONSIDERABLE UNCERTAINTY  
ACROSS THE HAWAIIAN ISLANDS IN THE PRECIPITATION FORECAST AMONG AVAILABLE  
FORECAST TOOLS 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  
NDJ 2018 A65 74.2 0.4 B50 26.4 36.6 43.0  
DJF 2019 A60 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 A55 71.7 0.4 B65 24.6 34.1 45.5  
MAM 2019 A45 72.0 0.5 B60 22.5 28.4 34.0  
AMJ 2019 A40 72.9 0.5 B50 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  
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  
KAHULUI  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
NDJ 2018 A65 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 A60 72.5 0.4 B70 4.2 6.2 8.2  
FMA 2019 A55 72.3 0.4 B65 3.2 4.1 6.4  
MAM 2019 A45 73.0 0.4 B60 2.5 3.5 4.6  
AMJ 2019 A40 74.3 0.5 B50 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  
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  
HONOLULU  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
NDJ 2018 A60 77.7 0.5 B60 3.9 5.6 8.8  
DJF 2019 A55 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 A50 73.8 0.4 B65 1.9 3.2 4.7  
MAM 2019 A45 74.8 0.4 B60 1.8 2.6 3.0  
AMJ 2019 A40 76.3 0.4 B50 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  
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  
LIHUE  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
NDJ 2018 A55 75.7 0.3 B60 8.6 12.1 16.9  
DJF 2019 A50 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 A45 72.1 0.5 B65 5.8 8.4 9.9  
MAM 2019 A40 72.8 0.5 B60 5.3 6.6 8.0  
AMJ 2019 A40 74.2 0.5 B50 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  
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  
FORECASTER: DAN COLLINS  
 
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 NOV 15, 2018.  
 

 
 
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