Drought in Hawaii, September 1 to 30, 2024

Area Forecast Discussion
National Weather Service Honolulu HI
843 PM HST Sat Aug 31 2024

.SYNOPSIS...
A weak low level trough will pass through the islands tonight
increasing cloud and shower trends, mainly over windward and
mountain areas. A lighter wind pattern will continue due to this
trough moving across the state with afternoon sea breezes over
most islands. High pressure will build in behind the trough on
Sunday, with a transition to more stable moderate to locally breezy
trade winds from Labor Day into next weekend.

&&

.DISCUSSION...
The satellite imagery this evening shows clouds and showers
ahead of a weak low level trough moving into the Big Island. This
trough associated with the remnants of former tropical cyclone
Hector. Expect increasing cloud and shower trends mainly over
windward and mountain areas of the eastern islands through
midnight HST, then as the trough continues to weaken and drift
westward, brief periods of windward and mountain shower activity
will spread to Oahu and Kauai through the morning hours.

Winds will remain fairly light and variable through Sunday morning as
this low level trough passes through the island chain. High
pressure will build in behind the trough as it passes through each
island on Sunday. More stable conditions due to large scale
subsidence and a lower temperature inversion will set up as trade
winds strengthen over the state. Returning trade winds will lower
dew point temperatures humidity levels just in time for Labor
Day. This drier moderate to locally breezy trade wind weather
pattern will continue through next weekend with only slight
variations in day to day wind speeds across the state as the ridge
north of the island changes strength.

&&

.AVIATION...
A more typical trade wind pattern of moderate to locally breezy
trades should return by Sunday afternoon as remnants of Gilma
move away from the islands. Low cigs and SHRA will mainly impact
windward and mauka areas tonight as an increase in moisture moves
in associated with the remnants of Hector. MVFR conds are possible
in SHRA, but generally VFR should prevail.

While no AIRMETs are currently in effect, AIRMET Sierra for mtn
obsc may be needed for windward locations as SHRA coverage
increases tonight through the morning hours.

&&

.MARINE...
Light to moderate southeast to south winds over the western end
of the state tonight will transition to moderate to locally fresh
easterly trades statewide by Sunday. As the ridge builds in north
of the state, moderate to locally strong trade winds will fill in
on Monday into the middle of next week. A Small Craft Advisory
(SCA) is likely for the windier waters and channels around Maui
County and the Big Island by Monday morning.

East facing shores will continue to decline Sunday before getting
a slight increase as trade winds return early next week. Generally
small surf will prevail on other shores. Small background swells
from the south and southeast will keep the surf from going
entirely flat for south facing shores. A small northwest swell
will continue to diminish through the weekend.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

DISCUSSION...Bohlin
AVIATION...Walsh
MARINE...Shigesato