Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
718 AM EST Sat Feb 21 2015
Valid 00Z Sun Feb 22 2015 - 00Z Sun Mar 01 2015
Guidance reasonably agrees that an amplified mid-upper level
trough now lifting to the northeast of the state supported a
trailing surface frontal push into the islands. This front and
modest moisture/shower focus will gradually rescede and diminish
over this weekend leading into a period of drier trade flow.
Pacific flow amplification should meanwhile slow the next main
upstream mid-upper level trough to the northwest of the islands.
Model and ensemble forecast spread and uncertainty remains below
normal in the pattern. A favored guidance composite continues to
indicates that an associated frontal system advances to the state
late next week leading to pooled moisture and organized showers
working into the west-central islands. This occurs as an amplified
downstream mid-upper level ridge settles to the northeast of the
Hawaiian Islands. This ridge may be undercut by a lower latitide
closed low that guidance shows should prove slow to approach the
Big Island from the east-southeast late next week, but may get
into close enough proximity in about a week to keep an eye on.