Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
719 AM EST Thu Jan 19 2017

Valid 00Z Fri Jan 20 2017 - 00Z Fri Jan 27 2017

Overall, the guidance is in rather good agreement through next
Thursday -- a compromise of the available guidance should serve
Hawai'i well.  The subtropical ridge will be in control through
Friday, keeping the state mostly dry.  As a strong surface high
moves by to the north in the wake of a cold front or shear line,
trade winds freshen from late Friday into late Sunday, which
should enhance showers on windward slopes.  On Sunday and Monday,
a TUTT cell/weak upper low moves by the chain, which would aid and
abet rain chances. A well-defined digging upper trough and strong
cold front passes through the archipelago by late Tuesday.  By
next Wednesday, another upper ridge will begin to build in from
west to east while an upper trough sharpens to the east, which
should lead to some resumption of the east-northeast trades.

Roth