Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
656 AM EST Thu Mar 05 2015

Valid 00Z Fri Mar 06 2015 - 00Z Fri Mar 13 2015

Continues to look like a wet pattern for Hawai'i. The 5/00Z
GEFS/ECENS and their deterministic runs were in good mass field
agreement across the eastern Pacific until 10/00Z. This should
allow one mid-level Subtropical disturbance to migrate eastward
and another system---a mid-latitude cutoff system---to replace it.


After 10/00Z, the differences are most evident in the northeastern
Gulf of Alaska and have indirect impacts on the energetic
mid-latitude cutoff 500mb low invof 37.5N 150W. The 5/00Z
deterministic solution (GFS/ECMWF) is a slower one---than the
ensemble means between 10/00Z and 11/00Z--- but both agree that
the upper-level system migrates northeastward towards 40N 140W
around 11/00Z. In the wake of this system...a mid-level trough
reinforces and/or introduces more 'mid-latitude' flow across
Hawai'i.

For the day 6-7 forecast, recommend blending the 5/00Z GEFS/ECENS
at a 30/70 ratio respectively---in anticipation of another intense
500mb cutoff low to emerge along 160W-165W and invof 35N around
12/00Z. The GFS/GEFS solution would be a more progressive
scenario, and the blended scheme would allow for a slower
evolution of the pattern ---at these time scales.

Vojtesak