Climate Prediction Center - Seasonal Outlook

Prognostic Discussion for Long-Lead Hawaiian Outlooks 
NWS Climate Prediction Center College Park MD 
830AM EST Thu Nov 21 2019 
 
MONTHLY FORECAST DISCUSSION VALID DECEMBER 2019 
 
Sea surface temperature (SST) anomalies are about positive one to two degrees Celsius surrounding the Hawaiian Islands during the previous week. 
 
For January 2019 through October 2019, rainfall total accumulations were: 
 
- Lihue Airport 26.46 inches (97 percent of normal) 
- Honolulu Airport 12.34 inches (108 percent of normal) 
- Kahului Airport 10.38 Inches (85 percent of normal) 
- Hilo Airport 79.35 Inches (80 percent of normal) 
 
The NCEP Climate Forecast System (CFS) and other climate models of the North American Multi-Model Ensemble (NMME) predict above normal SSTs around the Hawaiian Islands for December 2019. Model guidance from the NMME indicates anomalies of 1-2 degrees C above normal are expected to continue. This elevates the chances of above normal monthly mean air temperatures for Hawaii in December 2019. Equal chances (EC) of above, near or below normal precipitation is indicated over the Hawaiian Islands during December 2019, as dynamical model predictions of precipitation for the month vary widely. 
 
 
 





  TEMPERATURE   PRECIPITATION
    FCST  AVE  LIM  FCST  BLW  MEDIAN  ABV
 Hilo  A65  72.5  0.4   EC  6.8  10.2  13.6
 Kahului  A65  73.5  0.5   EC  1.9  2.7  3.4
 Honolulu  A65  74.9  0.6   EC  0.8  1.3  3.8
 Lihue  A65  73.3  0.5   EC  1.8  3.2  5.5
 
 
SEASONAL FORECAST DISCUSSION VALID DJF 2019 - DJF 2020 
 
Refer to the prognostic discussion of the long-lead seasonal outlooks for the CONUS and Alaska for a discussion of the ENSO outlook and other 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 across most of Pacific Ocean and are below average in parts of the eastern Pacific. Positive subsurface temperature anomalies have strengthened and moved eastward from the central Pacific to the eastern Pacific, while negative subsurface temperature anomalies have strengthened in the central Pacific. Low-level cross-equatorial wind anomalies are observed over the eastern equatorial Pacific Ocean, and upper-level westerly wind anomalies are present over the eastern Pacific. ENSO-neutral is likely to continue through the Northern Hemisphere winter 2019-2020 with probabilities about 70% and through spring 2020 with probabilities exceeding 60%. 
 
Enhanced probabilities for above normal temperatures are indicated across the Hawaiian Islands in the outlook from DJF 2019-2020 to AMJ 2020, due to predicted persistence of above normal sea surface temperatures in the NMME dynamical model forecasts, and supported by statistical models including the Constructed Analog (CA) and Optimum Climate Normals (OCN) through JJA 2020. The signal weakens at longer leads, therefore Equal Chances (EC) for above, near or below normal temperatures are indicated for Hawaii in JAS 2020 and thereafter. 
 
Most dynamical models  from the NMME predict greater probabilities for above normal precipitation over the Hawaiian Islands from DJF 2019-2020 through AMJ 2020, though some statistical tools such as the CA indicate below normal is more likely in the central islands during this period. Stronger signals  for above normal are indicated by the NMME over the northwestern islands in DJF 2019-2020 through FMA 2020. Increasing uncertainty in the tropical climate state in MJJ 2020 and thereafter leads to an indication of equal chances (EC) for above, near or below normal precipitation for Hawaii.
 
 
















 Hilo
  TEMPERATURE  PRECIPITATION
    FCST  AVE  LIM  FCST  BLW  MEDIAN  ABV
 DJF 2020  A65  72.8  0.4  A40  19.6  30.2  33.3
 JFM 2020  A60  71.8  0.4  A40  22.0  32.0  44.5
 FMA 2020  A55  71.7  0.4  A40  24.6  34.1  45.5
 MAM 2020  A45  72.0  0.5  A40  22.5  28.4  34.0
 AMJ 2020  A45  72.9  0.5  A40  21.4  23.7  29.0
 MJJ 2020  A40  74.0  0.4   EC  20.2  27.5  29.1
 JJA 2020  A40  75.2  0.4   EC  19.4  27.2  31.4
 JAS 2020   EC  76.1  0.4   EC  25.2  28.6  33.4
 ASO 2020   EC  76.4  0.4   EC  26.1  28.8  33.3
 SON 2020   EC  76.2  0.4   EC  24.3  30.2  40.8
 OND 2020   EC  75.5  0.4   EC  28.3  34.5  42.0
 NDJ 2020   EC  74.2  0.4   EC  26.4  36.6  43.0
 DJF 2021   EC  72.8  0.4   EC  19.6  30.2  33.3
 

















 Kahului
  TEMPERATURE  PRECIPITATION
    FCST  AVE  LIM  FCST  BLW  MEDIAN  ABV
 DJF 2020  A65  73.8  0.4  A40  4.6  6.9  8.7 
 JFM 2020  A55  72.5  0.4  A45  4.2  6.2  8.2 
 FMA 2020  A50  72.3  0.4  A45  3.2  4.1  6.4 
 MAM 2020  A45  73.0  0.4  A40  2.5  3.5  4.6 
 AMJ 2020  A40  74.3  0.5  A40  1.2  1.6  2.2 
 MJJ 2020  A40  76.0  0.5   EC  0.7  1.1  1.8 
 JJA 2020  A40  77.7  0.4   EC  0.7  1.1  1.5 
 JAS 2020   EC  79.0  0.4   EC  0.8  1.1  1.6 
 ASO 2020   EC  79.4  0.4   EC  0.8  1.6  2.5 
 SON 2020   EC  79.1  0.4   EC  2.1  3.3  4.8 
 OND 2020   EC  77.8  0.4   EC  4.2  5.3  8.1 
 NDJ 2020   EC  75.9  0.4   EC  5.2  7.6  9.5 
 DJF 2021   EC  73.8  0.4   EC  4.6  6.9  8.7 
 

















 Honolulu
  TEMPERATURE  PRECIPITATION
    FCST  AVE  LIM  FCST  BLW  MEDIAN  ABV
 DJF 2020  A65  75.3  0.5  A40  3.7  5.6  8.6 
 JFM 2020  A55  73.9  0.4  A50  2.1  4.6  7.8 
 FMA 2020  A50  73.8  0.4  A45  1.9  3.2  4.7 
 MAM 2020  A45  74.8  0.4  A40  1.8  2.6  3.0 
 AMJ 2020  A40  76.3  0.4  A40  1.2  1.6  1.8 
 MJJ 2020  A40  78.2  0.4   EC  0.8  1.4  1.6 
 JJA 2020  A40  79.9  0.4   EC  0.7  0.8  1.3 
 JAS 2020   EC  81.3  0.4   EC  1.0  1.4  1.7 
 ASO 2020   EC  81.7  0.4   EC  1.6  2.4  3.1 
 SON 2020   EC  81.4  0.4   EC  2.5  4.0  5.6 
 OND 2020   EC  80.0  0.4   EC  4.4  6.4  8.5 
 NDJ 2020   EC  77.7  0.5   EC  3.9  5.6  8.8 
 DJF 2021   EC  75.3  0.5   EC  3.7  5.6  8.6 
 

















 Lihue
  TEMPERATURE  PRECIPITATION
    FCST  AVE  LIM  FCST  BLW  MEDIAN  ABV
 DJF 2020  A65  73.6  0.4  A45  7.5  8.4  14.0
 JFM 2020  A60  72.2  0.4  A50  6.5  8.8  13.8
 FMA 2020  A55  72.1  0.5  A45  5.8  8.4  9.9 
 MAM 2020  A50  72.8  0.5  A40  5.3  6.6  8.0 
 AMJ 2020  A45  74.2  0.5  A40  4.7  5.5  6.0 
 MJJ 2020  A40  76.0  0.5   EC  4.9  5.4  5.9 
 JJA 2020  A40  77.7  0.4   EC  4.4  5.3  6.9 
 JAS 2020   EC  79.0  0.3   EC  5.3  6.1  7.8 
 ASO 2020   EC  79.4  0.3   EC  6.2  7.9  8.4 
 SON 2020   EC  79.1  0.3   EC  9.2  10.0  11.2
 OND 2020   EC  77.8  0.3   EC  9.2  11.7  15.6
 NDJ 2020   EC  75.7  0.3   EC  8.6  12.1  16.9
 DJF 2021   EC  73.6  0.4   EC  7.5  8.4  14.0
 

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 Dec 19, 2019.
 
 
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