Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
803 AM EDT Wed May 18 2016

Valid 00Z Thu May 19 2016 - 00Z Thu May 26 2016

The current Hawai'i forecast appears in relatively good agreement
among the 18/00Z model guidance suite for this 7-day period. 
There is excellent agreement among both the GFS/ECMWF ensemble
mean and deterministic solutions that a large subtropical ridge
and closed high aloft will continue mainly to the north and
northeast of Hawai'i over the next 6 days.  Beyond this time, the
ensemble means suggest more of a zonal flow pattern aloft compared
to both of the deterministic runs.  More differences are evident
with a large scale trough south of the Aleutians and northwest of
Hawai'i around day 5, and both deterministic runs suggest a rather
strong closed 500mb low.  However, the effects of this feature
should remain well to the north of the region.  At the surface,
easterly trade winds averaging 10 to 20 knots should prevail
through the period with little in the way of fluctuation owing to
the persistence of the large surface high to the northeast. 
Overall, a blend of the 18/00Z deterministic GFS/ECMWF and their
ensemble mean solutions should maintain a stable medium range
forecast for Hawai'i.

Hamrick