Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
351 AM EDT Sun Apr 24 2022

Valid 00Z Mon Apr 25 2022 - 00Z Mon May 02 2022

Surface high pressure to the north of Hawaii will keep a breezy
easterly trade wind pattern in place through the early part of the
week. Windward and mountain/mauka showers are most common in this
wind regime, though some leeward showers could spill over
depending on the strength of the trades. While moisture
(precipitable water) values are likely to stay above normal for
the next day or so, a capping inversion should not allow for
widespread heavy rain, and PWs will decrease closer to normal by
Monday. By around midweek, a weakness in the subtropical ridge
could lead to a period of weaker trades, with potential for them
to strengthen somewhat during the latter part of the week, but
this remains uncertain. Meanwhile, modest upper troughing aloft
looks to come into Hawaii later this week, which could promote a
weakening capping inversion and allow for more vertical cloud
development. The ECMWF and the EC mean indicate that PW values may
increase as well by around Thursday-Saturday, which could lead to
more widespread showers. However, there is still considerable
uncertainty with this possibility since the GFS suite has some
hints of higher PWs but is not as aggressive, so this will
continue to be monitored.

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