PROGNOSTIC DISCUSSION FOR LONG-LEAD HAWAIIAN OUTLOOK
CLIMATE PREDICTION CENTER NCEP
NATIONAL WEATHER SERVICE WASHINGTON DC
3 PM EDT THURSDAY OCTOBER 14 1999
PROGNOSTIC DISCUSSION OF HAWAIIAN OUTLOOKS
MONTHLY OUTLOOK DISCUSSION - NOVEMBER 1999
SSTS NEAR HAWAII CURRENTLY AVERAGE ABOUT ONE-HALF DEGREE C BELOW NORMAL -
RANGING FROM A LITTLE MORE NEAR THE BIG ISLAND OF HAWAII TO A LITTLE LESS
NEAR THE NORTHWESTERN ISLANDS. FOR A DISCUSSION OF THE SSTS IN THE EQUATORIAL
PACIFIC REFER TO THE 90 DAY MESSAGE. SINCE THERE IS NO NEW PREDICTIVE DATA
FROM CCA - WE ARE CONSERVATIVELY FOLLOWING THE RECENT OBSERVED RESPONSES IN
SURFACE TEMPERATURE ANOMALIES TO THE BELOW NORMAL SSTS. THERE DOES NOT APPEAR
TO BE ANY BASIS FOR PREDICTING OTHER THAN CLIMATOLOGY FOR PRECIPITATION.
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
HILO B8 74.1 0.5 CL 9.4 12.9 17.2
KAHULUI CL 75.7 0.6 CL 1.2 1.9 2.9
HONOLULU N2 77.2 0.6 CL 0.9 1.8 3.1
LIHUE B2 75.5 0.5 A5 3.5 4.7 6.2
SEASONAL OUTLOOK DISCUSSION NOV-DEC-JAN 1999-2000 TO NOV-DEC-JAN 2000-2001
REFER TO THE 90 DAY DISCUSSION FOR FORECASTS FOR THE EQUATORIAL PACIFIC SSTS.
LA NINA CONDITIONS - WHICH HAD WEAKENED DURING MARCH TO JUNE BUT HAVE NOW
RESTRENGTHENED TO A MODERATE LEVEL - ARE FORECAST TO CONTINUE AT A MODERATE TO
STRONG INTENSITY THROUGH THE WINTER MONTHS WITH A RAPID WEAKENING THEREAFTER.
THIS SHOULD BE THE PRIMARY PREDICTABLE INFLUENCE ON THE HAWAIIAN FORECASTS
THROUGH MAM 2000. CCA INDICATIONS FROM LAST MONTH SHOW BELOW NORMAL TEMPERA-
TURES OVER MOST ISLANDS FROM NDJ 99 ONWARDS THROUGH THE FIRST HALF OR SO OF
NEXT YEAR.
THE CCA GIVES VERY FEW SIGNIFICANT SIGNALS FOR THE PRECIPITATION FORECAST FOR
ANY LEADS. LA NINA COMPOSITES INDICATE SOME WETNESS - PRIMARILY FOR LIHUE -
DURING THE UPCOMING WINTER AND EARLY SPRING SEASONS. FOR MOST SEASONS AND
LOCATIONS WE DECIDED ON CLIMATOLOGICAL PROBABILITIES DUE TO GENERALLY WEAK
AND VARIABLE INDICATIONS.
CLARIFICATION: CL INDICATES CLIMATOLOGICAL PROBABILITIES - WHICH MEANS THAT
NO PARTICULAR TILT OF THE ODDS TOWARD ABOVE - NEAR - OR BELOW NORMAL
CONDITIONS IS FORECAST. A5 (EXAMPLE) MEANS A 5% HIGHER THAN NORMAL CHANCE
THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE ABOVE CLASS. B3 (EXAMPLE)
MEANS A 3% HIGHER THAN NORMAL PROBABILITY THAT TEMPERATURE OR PRECIPITATION
WILL BE IN THE BELOW CLASS. N2 (EXAMPLE) MEANS A 2% HIGHER THAN NORMAL
PROBABILITY THAT TEMPERATURE OR PRECIPITATION WILL BE IN THE NEAR NORMAL
CLASS.
NOTE -- THE HAWAIIAN FORECAST IS USUALLY BASED MAINLY ON THE CCA TOOL AND ENSO
CONSIDERATIONS - WITH INPUT FROM THE COUPLED MODEL AT SHORTER LEADS. SINCE
THERE IS NO NEW CCA OR COUPLED MODEL OUTPUT THIS MONTH - WE ARE CONSERVATIVELY
FOLLOWING THE INDICATIONS FROM LAST MONTHS FORECAST.
HILO
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 1999 B5 72.7 0.4 CL 27.0 34.0 42.2
DJF 1999 B2 71.9 0.5 CL 19.8 27.1 36.1
JFM 2000 CL 71.8 0.5 CL 22.8 30.2 39.1
FMA 2000 CL 72.1 0.5 CL 30.5 37.2 44.7
MAM 2000 CL 72.8 0.5 CL 30.4 36.8 44.1
AMJ 2000 CL 73.9 0.5 CL 24.2 29.4 35.4
MJJ 2000 CL 75.0 0.5 CL 20.5 24.5 29.0
JJA 2000 CL 75.8 0.4 CL 19.7 23.8 28.5
JAS 2000 CL 76.1 0.4 CL 22.0 26.2 30.9
ASO 2000 CL 76.0 0.4 CL 23.3 26.6 30.3
SON 2000 A3 75.3 0.4 CL 25.7 31.2 37.4
OND 2000 A3 74.1 0.4 CL 27.1 33.9 41.7
NDJ 2000 A2 72.7 0.4 CL 27.0 34.0 42.2
KAHULUI
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 1999 N5 73.5 0.4 CL 6.7 8.8 11.4
DJF 1999 N2 72.2 0.5 CL 6.9 9.0 11.5
JFM 2000 B3 72.1 0.5 A2 6.7 8.7 11.1
FMA 2000 B3 72.9 0.5 A2 4.7 6.4 8.5
MAM 2000 B6 74.2 0.5 CL 3.0 4.4 6.1
AMJ 2000 B3 75.7 0.5 CL 1.1 1.9 3.1
MJJ 2000 B3 77.3 0.6 CL 0.6 1.0 1.6
JJA 2000 CL 78.5 0.5 CL 0.6 0.9 1.3
JAS 2000 CL 78.9 0.5 CL 0.8 1.1 1.4
ASO 2000 CL 78.6 0.5 CL 1.2 1.7 2.4
SON 2000 A2 77.4 0.5 CL 2.4 3.4 4.8
OND 2000 CL 75.5 0.5 CL 4.8 6.3 8.1
NDJ 2000 CL 73.5 0.4 CL 6.7 8.8 11.4
HONOLULU
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 1999 N2 74.7 0.4 CL 6.7 9.0 11.4
DJF 1999 CL 73.3 0.4 A2 6.2 8.3 10.9
JFM 2000 B3 73.4 0.5 A3 5.0 6.9 9.1
FMA 2000 B5 74.4 0.5 A2 3.7 5.1 6.8
MAM 2000 B7 75.9 0.5 CL 2.5 3.8 5.5
AMJ 2000 B7 77.6 0.5 CL 1.5 2.4 3.6
MJJ 2000 B3 79.1 0.5 CL 1.1 1.7 2.5
JJA 2000 CL 80.4 0.5 CL 0.9 1.3 1.8
JAS 2000 CL 81.0 0.5 CL 1.3 1.7 2.1
ASO 2000 CL 80.7 0.5 CL 1.8 2.8 4.0
SON 2000 A3 79.3 0.5 CL 3.6 5.1 6.9
OND 2000 A4 77.0 0.5 CL 6.0 8.0 10.4
NDJ 2000 A2 74.7 0.4 CL 6.7 9.0 11.4
LIHUE
TEMPERATURE PRECIPITATION
FCST AVE LIM FCST BLW MEDIAN ABV
NDJ 1999 B2 73.3 0.4 A7 12.1 15.2 18.7
DJF 1999 B4 72.0 0.5 A8 10.5 13.3 16.6
JFM 2000 B10 72.0 0.6 A8 9.1 11.9 15.3
FMA 2000 B12 72.8 0.6 A7 7.8 10.0 12.6
MAM 2000 B12 74.1 0.6 CL 7.7 9.9 12.3
AMJ 2000 B6 75.8 0.5 CL 5.8 7.5 9.5
MJJ 2000 B5 77.5 0.4 CL 4.9 6.3 8.0
JJA 2000 B2 78.7 0.4 CL 4.5 5.3 6.2
JAS 2000 CL 79.2 0.4 CL 4.9 5.9 7.0
ASO 2000 CL 78.7 0.4 CL 6.2 7.8 9.7
SON 2000 CL 77.4 0.4 CL 9.3 11.4 13.8
OND 2000 CL 75.3 0.4 CL 10.8 13.7 17.1
NDJ 2000 CL 73.3 0.4 A7 12.1 15.2 18.7
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 THURSDAY NOVEMBER 18 1999.
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