Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
248 AM EST Sun Jan 23 2022

Valid 00Z Mon Jan 24 2022 - 00Z Mon Jan 31 2022

Expect moderate to brisk trades with windward/mountain focus for
showers through the next few days as one surface high
north-northeast of the state migrates into the eastern Pacific and
a trailing high passes by to the north.  The front separating
these highs will likely stall far enough north around Wednesday
not to have an effect.  Consensus shows relatively drier air over
the state into Monday, keeping rainfall totals light.  An area of
moisture brushing the Big Island and vicinity by Tuesday-Wednesday
may increase rainfall somewhat.  For now, moisture differences
seen in the guidance 24 hours ago have been resolved by the 00Z
GFS/ECMWF trending to a middle ground.  Moisture may decrease a
bit later in the week.  By next weekend the guidance suggests a
transition in the pattern as upper troughing and a leading front
approach from the west.  This may promote an increased
southeasterly/southerly component to low level winds.  Guidance is
split over whether the associated increase in moisture will reach
into the western islands by Sunday, with the 00Z GFS/GEFS faster
than the 00Z ECMWF/12Z ECMWF mean.  The 00Z CMC tilts in the GFS
direction but a very high percentage of 00Z CMCens/12Z ECens
members and a moderate number of of 00Z GEFS members would suggest
the GFS could be overdone with its southeastward amplitude of the
upper trough.  Prefer a compromise approach while awaiting more
information from clustering and trends.   

Rausch