Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
729 AM EST Fri Feb 23 2018

Valid 00Z Sat Feb 24 2018 - 00Z Sat Mar 03 2018

Satellite imagery and local radars show an active weather pattern
ongoing across Hawaii with heaviest activity currently
concentrated over the central and southern islands in an axis of
deepened tropical moisture. A flash flood watch remains in effect
across the state and winter weather warnings are in place across
the Big Island summits of Mauna Loa and Mauna Kea.

Models and ensembles reasonably agree and a favored composite
solution still shows a blocky mid-upper level flow pattern over
the east-central Pacific highlighted by an upper low to the
northwest of the Hawaiian Islands and a downstream narrow ridge
along 150W. This setup is favoring a surge of deep tropical
moisture northward across the state over the next couple of days
to fuel potential of locally moderate to heavy rain and embedded
thunderstorms. Precipitable water values are forecast to rise to
between about 1 1/3 to 1 3/4 inches through the period which is
well above average for late February.

The lead closed low is slated to lift away from the state Sunday.
Another upper low may form in its wake into next midweek just west
of 170W. This may pull the deepest precipitable water axis
westward next week, perhaps west of Kauai/Ni'ihau. Trades should
meanwhile build through next week as strong high pressure settles
to the northwest of the state in a pattern with limited windward
terrain showers.

Schichtel