Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
227 AM EST Fri Mar 12 2021

Valid 00Z Sat Mar 13 2021 - 00Z Sat Mar 20 2021

Strong upper ridging over the northwestern North Pacific and
northeastern North Pacific will promote troughing near Hawai'i for
the next week or so. Weakening upper low near the area will be
overtaken by another upper trough and surface cold front early
Sat, bringing a reprieve from the humid and rainy pattern of late.
Winds will turn briskly northeasterly as drier air moves in during
the day. For next week, models and ensembles show weak troughing
over the area as an extension to the southwest of deeper troughing
as an upper low settles into the northeastern Pacific. The 00Z GFS
favors keeping appreciable moisture to the south of the area until
later next week when it may creep up from the southwest but the
ECMWF was much more robust and brought a wave to the area from the
east with almost no down time in between. Prefer the GFS scenario
as the ECMWF has undergone considerable changes in the eastern
Pacific flow the past two cycles whereas the GFS has been much
more stable. This would keep breezy northeasterly trades over the
area next week with windward/mauka showers but only light to
perhaps modest amounts especially by the end of next week as
precipitable water values rise back to over one inch.


Fracasso