Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
800 AM EDT Wed Apr 29 2015

Valid 00Z Thu Apr 30 2015 - 00Z Thu May 07 2015

The 29/00Z guidance was in rather good agreement with all the
prominent Pacific sensible weather features. For Hawai'i---its the
surface high migrating west-to-east along 35N latitude---and its
intensity that produces  the appreciable uptick in tradewind
strength during the next 18-36 hours.

By Friday (1/12Z), the migratory surface ridge is on track to move
northeastward---weaken and ease the tradewind flow over the
weekend (days 3-4). High pressure begins to rebuild across the
east central Pacific early next week in response to a deep
mid-latitude upper-level cyclone and trough setting up invof 50N
and 160W very near the 6/12Z time frame (day 7). The trend in the
last couple of forecast cycles (12Z and 00Z versions) suggest a
more amplified flow pattern will be created---ahead of the day 7
trough.

Thought the embedded energy within the trough is more closely
depicted by the 29/00Z ECENS and its deterministic ECMWF run. The
NAEFS/GEFS means are just as reasonable solutions---though the
deterministic 29/00Z GFS would be a very sheared solution across
the mid-latitude Pacific by day 6 and would not necessarily 'fit'
the amplified trend of the 3 means heading into the day 8 time
frame (7/12Z).

Vojtesak