Hawaii 30 & 90 Day Narrative

115 
FXHW40 KWBC 201231
PMDHCO
Prognostic Discussion for Long-Lead Hawaiian Outlooks
NWS Climate Prediction Center College Park MD
830AM EDT Thu Jun 20 2019
MONTHLY FORECAST DISCUSSION VALID JULY 2019
Sea surface temperature (SST) anomalies are around positive one to two degrees 
Celsius surrounding the Hawaiian Islands during the previous week.
For January 2019 through May 2019, rainfall total accumulations were:
- Lihue Airport 8.53 inches (54 percent of normal)
- Honolulu Airport 3.08 inches (41 percent of normal)
- Kahului Airport 9.50 Inches (100 percent of normal)
- Hilo Airport 34.53 Inches (67 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 July 2019. This elevates the chances of above normal 
monthly mean air temperatures for Hawaii in July 2019. Most dynamical models 
predict above normal precipitation over the Hawaiian Islands during July 2019, 
consistent with the Canonical Correlation Analysis (CCA) forecast tool. 
           TEMPERATURE           PRECIPITATION
          FCST   AVE    LIM  FCST  BLW  MEDIAN  ABV
Hilo       A60   76.2   0.4  A40   7.1   9.5   11.4
Kahului    A60   79.2   0.4  A40   0.2   0.4   0.5
Honolulu   A60   81.4   0.5  A40   0.2   0.4   0.5
Lihue      A60   79.2   0.4  A40   1.5   1.7   1.9
SEASONAL FORECAST DISCUSSION VALID JAS 2019 - JAS 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. Weak EL Nino conditions currently are 
present, and equatorial sea surface temperatures (SSTs) are above average, 
across most of the equatorial Pacific Ocean. Positive subsurface temperature 
anomalies have weakened, but still reside near the surface across the central 
Pacific, while negative subsurface temperature anomalies have strengthened in 
the western and eastern Pacific. Enhanced convection persisted over the Date 
Line, and low-level wind anomalies were westerly over the western tropical 
Pacific Ocean. Upper-level wind anomalies were easterly over the western and 
east-central Pacific. A weak El Nino is likely to continue through the Northern 
Hemisphere summer 2019 (with a 66% chance) and possibly through the fall and 
winter (50-55% chance). 
Enhanced probabilities for above normal temperatures are indicated across the 
Hawaiian Islands in the outlook from JAS to NDJ 2019, due to persistent above 
normal sea surface temperatures predicted by the NMME dynamical models, which 
is also supported by statistical models including the Canonical Correlation 
Analysis (CCA) and Constructed Analog (CA). The signal weakens at longer leads, 
therefore Equal Chances (EC) for above, near, or below normal temperatures are 
indicated for Hawaii beginning in DJF 2019-2020 and beyond.
With enhanced probabilities of the continuation of an El Nino through summer, 
the precipitation forecast for Hawaii follows historical El Nino impacts that 
indicate strong correlations between El Nino and increased probabilities of 
below normal precipitation in winter and spring and weaker correlations between 
El Nino and above normal precipitation in summer, due to potential impacts from 
enhanced tropical cyclone activity in the central Pacific during summer El Nino 
conditions. Most dynamical models predict larger signals for above normal 
precipitation over the Hawaiian Islands during JAS to SON 2019, supported by 
the Constructed Analog statistical forecast of precipitation, which also are 
consistent with an ENSO-OCN tool that combines the impacts of El Nino and 
decadal climate variability.  Increasing uncertainty in the tropical climate 
state in OND 2019 and longer leads, 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
JAS 2019  A55  76.1   0.4   A45   25.2   28.6   33.4
ASO 2019  A60  76.4   0.4   A45   26.1   28.8   33.3
SON 2019  A50  76.2   0.4   A40   24.3   30.2   40.8
OND 2019  A45  75.5   0.4    EC   28.3   34.5   42.0
NDJ 2019  A40  74.2   0.4    EC   26.4   36.6   43.0
DJF 2020   EC  72.8   0.4    EC   19.6   30.2   33.3
JFM 2020   EC  71.8   0.4    EC   22.0   32.0   44.5
FMA 2020   EC  71.7   0.4    EC   24.6   34.1   45.5
MAM 2020   EC  72.0   0.5    EC   22.5   28.4   34.0
AMJ 2020   EC  72.9   0.5    EC   21.4   23.7   29.0
MJJ 2020   EC  74.0   0.4    EC   20.2   27.5   29.1
JJA 2020   EC  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
                      Kahului
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JAS 2019  A50  79.0   0.4   A45   0.8    1.1    1.6 
ASO 2019  A55  79.4   0.4   A45   0.8    1.6    2.5 
SON 2019  A50  79.1   0.4   A40   2.1    3.3    4.8 
OND 2019  A45  77.8   0.4    EC   4.2    5.3    8.1 
NDJ 2019  A40  75.9   0.4    EC   5.2    7.6    9.5 
DJF 2020   EC  73.8   0.4    EC   4.6    6.9    8.7 
JFM 2020   EC  72.5   0.4    EC   4.2    6.2    8.2 
FMA 2020   EC  72.3   0.4    EC   3.2    4.1    6.4 
MAM 2020   EC  73.0   0.4    EC   2.5    3.5    4.6 
AMJ 2020   EC  74.3   0.5    EC   1.2    1.6    2.2 
MJJ 2020   EC  76.0   0.5    EC   0.7    1.1    1.8 
JJA 2020   EC  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 
                      Honolulu
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JAS 2019  A50  81.3   0.4   A45   1.0    1.4    1.7 
ASO 2019  A55  81.7   0.4   A45   1.6    2.4    3.1 
SON 2019  A50  81.4   0.4   A40   2.5    4.0    5.6 
OND 2019  A45  80.0   0.4    EC   4.4    6.4    8.5 
NDJ 2019  A40  77.7   0.5    EC   3.9    5.6    8.8 
DJF 2020   EC  75.3   0.5    EC   3.7    5.6    8.6 
JFM 2020   EC  73.9   0.4    EC   2.1    4.6    7.8 
FMA 2020   EC  73.8   0.4    EC   1.9    3.2    4.7 
MAM 2020   EC  74.8   0.4    EC   1.8    2.6    3.0 
AMJ 2020   EC  76.3   0.4    EC   1.2    1.6    1.8 
MJJ 2020   EC  78.2   0.4    EC   0.8    1.4    1.6 
JJA 2020   EC  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 
                      Lihue
          TEMPERATURE           PRECIPITATION
         FCST   AVE   LIM  FCST   BLW  MEDIAN   ABV
JAS 2019  A50  79.0   0.3   A45   5.3    6.1    7.8 
ASO 2019  A55  79.4   0.3   A45   6.2    7.9    8.4 
SON 2019  A50  79.1   0.3   A40   9.2    10.0   11.2
OND 2019  A45  77.8   0.3    EC   9.2    11.7   15.6
NDJ 2019  A40  75.7   0.3    EC   8.6    12.1   16.9
DJF 2020   EC  73.6   0.4    EC   7.5    8.4    14.0
JFM 2020   EC  72.2   0.4    EC   6.5    8.8    13.8
FMA 2020   EC  72.1   0.5    EC   5.8    8.4    9.9 
MAM 2020   EC  72.8   0.5    EC   5.3    6.6    8.0 
AMJ 2020   EC  74.2   0.5    EC   4.7    5.5    6.0 
MJJ 2020   EC  76.0   0.5    EC   4.9    5.4    5.9 
JJA 2020   EC  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 
FORECASTER: Luke He
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 Jul 18, 2019.
$$