Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Honolulu HI
1000 am HST Tuesday Sep 16 2014
a surface ridge near the islands and dry...stable air aloft...will
maintain light winds and light rainfall through the work week. A
tropical wave passing south of the area may bring an increase in
rainfall...and boost wind speeds a bit starting over the weekend.
a surface ridge north of the islands will maintain gentle trade
winds over the islands for the next couple of days. There will be
windward showers during the nights and mornings and spotty showers
over interior and leeward areas in the afternoons. The atmosphere
will be rather dry and stable so rainfall will be light.
A front approaching from the northwest will weaken the ridge by
Thursday and the trades will become light enough to allow local sea
and land breezes to prevail through Saturday. This pattern will
bring mostly clear nights and mornings with spotty showers over
interior areas during the afternoons and evenings.
A tropical wave is forecast to move over the islands from the
southeast starting Saturday night and linger over the area through
early next week. Winds will strengthen a bit Saturday night through
Sunday night as the wave is approaching...then become light and
variable again Monday as the trough moves over the islands. The
tropical wave will bring an increase in moisture by Sunday so
rainfall amounts will likely increase. Locally heavy showers are
possible...but the timing and amount of moisture are still uncertain.
VFR conditions will prevail for the next couple of days with only
localized MVFR ceilings over the slopes. Clouds and showers will be
most prevalent over windward slopes during the nights and mornings
and over the leeward slopes during the afternoons and evenings.
a high surf advisory remains in effect for south facing shores
of all islands through 600 PM today. Swell heights at the Barbers
Point buoy continue to run slightly above wavewatch guidance...but
the swell period is gradually decreasing. We will be watching to
see if the high surf advisory needs to be extended beyond 600 PM. A
series of north northwest swells will roll in...but surf along north
facing shores will remain well below advisory levels.
Winds and seas are expected to remain below Small Craft Advisory
high surf advisory until 600 PM HST this evening for south facing
shores of all islands.