Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
800 AM EDT Wed Sep 16 2015

Valid 00Z Thu Sep 17 2015 - 00Z Thu Sep 24 2015

Moderate trades and scattered showers are expected during this
7-day forecast period.

The 16/00Z ECENS/GEFS blend and their deterministic runs were
decent pieces of guidance---and support the current Hawai'i
forecast through 23/12Z (mid-point day7).

Aloft---the deterministic 16/00Z ECMWF/GFS solutions continue to
follow the westward migration (between 140W and 150W)--- of a TUTT
cell along 25N through this weekend (21/00Z). Then recurves the
system eastward --- on the heels of a developing Subtropical Jet
streak that will extend northeastward into southern California.

The TUTT still appears to maintain a 'convective nature' with
plenty of shear and isolated thunderstorm potential---as it
positions itself north of the Islands. And behind the exiting TUTT
feature---weak upper-level troughing over the east central Pacific
and Gulf of Alaska should descend into the Subtropics.  

Vojtesak