Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
716 AM EST Wed Feb 22 2017

Valid 00Z Thu Feb 23 2017 - 00Z Thu Mar 02 2017

Despite a number of systems in the mid-latitudes and a wealth of
moisture southeast of the state, the theme for the next week will
be mostly dry for the Hawaiian Islands. Precipitable water values
will remain below an inch through Friday and gradually creep
upwards through the weekend into early/mid next week. A closed mid
to upper low near 40n 157w will drift off to the south and east
over the next couple of days, while another batch of upper
dynamics detach from the westerlies and close off in a similar
location for the weekend. In both instances, the cold frontal
zones will not reach the state. Meanwhile, a wealth of tropical
moisture pooling southeast of the state will gradually return to
the north and east over the next week. Precipitable water values
will increase over the weekend into next week to over an inch and
the gfs/ecmwf show quite a disturbance aloft with mid-level
vorticity possibly clipping the Big Island at best. This would
increase rain chances Sun/Mon for the Big Island but the heaviest
rainfall will remain well south and east of the state. Overall
expect northeasterly to easterly trades, perhaps southeasterly
next week with increasing moisture content, and windward showers
for the most part.

Musher