895  
FXHW40 KWBC 211231  
PMDHCO  
PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
830AM EDT THU JUN 21 2018  
 
MONTHLY FORECAST DISCUSSION VALID JULY 2018  
 
SEA SURFACE TEMPERATURE (SST) ANOMALIES ARE CURRENTLY AROUND ZERO TO POSITIVE  
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 MAY 2018, RAINFALL TOTAL ACCUMULATIONS WERE:  
 
- LIHUE AIRPORT 25.94 INCHES (164 PERCENT OF NORMAL)  
 
- HONOLULU AIRPORT 8.19 INCHES (108 PERCENT OF NORMAL)  
 
- KAHULUI AIRPORT 13.70 INCHES (144 PERCENT OF NORMAL)  
 
- HILO AIRPORT 65.00 INCHES (125 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 JULY 2018. THIS ELEVATES THE  
CHANCES OF ABOVE NORMAL MONTHLY MEAN AIR TEMPERATURES FOR HAWAII IN JULY 2018.  
MOST DYNAMICAL TOOLS ALSO FAVOR ABOVE NORMAL PRECIPITATION FOR HAWAIIAN ISLANDS  
DURING JULY 2018.  
 
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
HILO A65 76.2 0.4 A60 7.1 9.5 11.4  
KAHULUI A60 79.2 0.4 A60 0.2 0.4 0.5  
HONOLULU A50 81.4 0.5 A50 0.2 0.4 0.5  
LIHUE A40 79.2 0.4 A40 1.5 1.7 1.9  
 
SEASONAL FORECAST DISCUSSION VALID JAS 2018 - JAS 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 PACIFIC  
OCEAN, AND ABOVE AVERAGE IN THE WESTERN PACIFIC. POSITIVE SUBSURFACE  
TEMPERATURE ANOMALIES HAVE INTENSIFIED AND EXPANDED ACROSS THE EQUATORIAL  
PACIFIC OCEAN,WHILE NEGATIVE SUBSURFACE TEMPERATURE ANOMALIES HAVE  
DISSIPATED IN THE FAR EASTERN PACIFIC OCEAN. CONVECTION REMAINED SUPPRESSED  
NEAR THE DATE LINE, WHILE LOW-LEVEL AND UPPER-LEVEL WIND ANOMALIES WERE NEAR  
AVERAGE ACROSS THE TROPICAL PACIFIC OCEAN. MOST MODELS INDICATE ENSO-NEUTRAL TO  
CONTINUE AT LEAST THROUGH THE NORTHERN HEMISPHERE SUMMER 2018, WITH THE  
PROBABILITY OF EL NINO NEARING 50% DURING THE NORTHERN HEMISPHERE AUTUMN,  
INCREASING TO ABOUT 65% BY NORTHERN HEMISPHERE WINTER 2018-19.  
 
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR HAWAII  
FROM JAS 2018 TO DJF 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 JFM 2019 AND BEYOND.  
 
DYNAMICAL TOOLS AND CONSTRUCTED ANALOG TOOL FAVOR ABOVE NORMAL PRECIPITATION  
FOR HAWAII FROM JAS TO SON 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  
FALL OR 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 MAM 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  
JAS 2018 A65 76.1 0.4 A45 25.2 28.6 33.4  
ASO 2018 A60 76.4 0.4 A40 26.1 28.8 33.3  
SON 2018 A55 76.2 0.4 EC 24.3 30.2 40.8  
OND 2018 A50 75.5 0.4 EC 28.3 34.5 42.0  
NDJ 2018 A45 74.2 0.4 B50 26.4 36.6 43.0  
DJF 2019 A40 72.8 0.4 B50 19.6 30.2 33.3  
JFM 2019 EC 71.8 0.4 B50 22.0 32.0 44.5  
FMA 2019 EC 71.7 0.4 B40 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  
JAS 2019 EC 76.1 0.4 EC 25.2 28.6 33.4  
\N KAHULUI  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
JAS 2018 A65 79.0 0.4 A45 0.8 1.1 1.6  
ASO 2018 A60 79.4 0.4 A40 0.8 1.6 2.5  
SON 2018 A55 79.1 0.4 EC 2.1 3.3 4.8  
OND 2018 A50 77.8 0.4 EC 4.2 5.3 8.1  
NDJ 2018 A45 75.9 0.4 B50 5.2 7.6 9.5  
DJF 2019 A40 73.8 0.4 B50 4.6 6.9 8.7  
JFM 2019 EC 72.5 0.4 B50 4.2 6.2 8.2  
FMA 2019 EC 72.3 0.4 B40 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  
JAS 2019 EC 79.0 0.4 EC 0.8 1.1 1.6  
\N HONOLULU  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
JAS 2018 A60 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 A50 80.0 0.4 EC 4.4 6.4 8.5  
NDJ 2018 A45 77.7 0.5 B50 3.9 5.6 8.8  
DJF 2019 A40 75.3 0.5 B50 3.7 5.6 8.6  
JFM 2019 EC 73.9 0.4 B50 2.1 4.6 7.8  
FMA 2019 EC 73.8 0.4 B40 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  
JAS 2019 EC 81.3 0.4 EC 1.0 1.4 1.7  
\N LIHUE  
TEMPERATURE PRECIPITATION  
FCST AVE LIM FCST BLW MEDIAN ABV  
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 A50 77.8 0.3 EC 9.2 11.7 15.6  
NDJ 2018 A45 75.7 0.3 B50 8.6 12.1 16.9  
DJF 2019 A40 73.6 0.4 B50 7.5 8.4 14.0  
JFM 2019 EC 72.2 0.4 B50 6.5 8.8 13.8  
FMA 2019 EC 72.1 0.5 B40 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  
JAS 2019 EC 79.0 0.3 EC 5.3 6.1 7.8  
\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 JUL 19, 2018.  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page