Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
334 AM EDT Sun Jun 13 2021

Valid 00Z Mon Jun 14 2021 - 00Z Mon Jun 21 2021

The latest models and ensembles offer similar ideas and good
continuity for the pattern during the next seven days.  High
pressure initially north of the area will continue eastward and
settle over the eastern Pacific from Wednesday onward.  Flow
around this high will bring moderate to occasionally brisk trades
to the islands with a windward/mountain focus for showers, though
scattered rain may fall elsewhere at times.  Overall expect
rainfall totals to trend somewhat higher with time, as an upper
ridge over the area through this weekend is replaced by a
weakness/possible upper low that persists into next weekend and
precipitable water increases from its lower than climatological
values after early this week.  A band of moisture associated with
a weakening front may brush the northwestern islands around
Tuesday-Wednesday but current consensus (improved by a northward
adjustment from yesterday's 00Z GFS) suggests most of modestly
enhanced rainfall will stay just to the north.  Away from this
moisture band the models and ensembles also show precipitable
water values reaching somewhat above normal over most of the state
for the latter half of the week.  By next weekend the 00Z ECMWF
and 00Z GEFS mean/12Z ECMWF mean all show moisture decreasing
slightly to near climatology while the 00Z GFS shows higher
values, especially over the southeastern islands.

Rausch