Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
820 AM EDT Sun May 29 2016

Valid 00Z Mon May 30 2016 - 00Z Mon Jun 6 2016

The beginning of the forecast period will be featured with a break
in the ridge to the north of the islands with a weak cold front in
the region through Tuesday.  There is good overall ensemble mean
agreement between the 6Z GEFS mean and 00Z EC mean, with the GEFS
mean indicating slightly more in the way of upper level troughing
near 20 degrees north than the EC mean in terms of 500mb heights. 
The operational ECMWF also showed more of a trough than its mean,
thus giving more weight to the GEFS mean for the upper level
pattern.

Surface pressure pattern projections suggest relatively weak
southeasterly winds that change to northeasterly winds on the
other side of the boundary.  Toward the middle part of the
upcoming week, upper level ridging becomes more established with a
surface high centered north of the state.  This will support an
increase in the easterly trades with velocities on the order of 15
to 20 knots.  By the end of the period, there is another sign of a
break in the surface high with a weak boundary to the north.  In
response, the trades are forecast to diminish in strength by the
end of next week.  Rainfall chances should pick up during the
period of peak trades as precipitable waters average around 1.5
inches.

Hamrick