Drought in Hawaii, March 5 to 31, 2024

Area Forecast Discussion
National Weather Service Honolulu HI
839 PM HST Mon Mar 4 2024

.SYNOPSIS...
A wet trade wind pattern with isolated thunderstorms and locally
heavy rain, especially over windward areas, will prevail through
Wednesday night. Breezy trades will further strengthen during the
middle part of the week.

&&

.DISCUSSION...
No changes to the forecast or the overall forecast philosophy this
evening. High pressure to the north, and a weakening surface
trough moving to the west and exiting the main Hawaiian islands is
helping to bring breezy trade winds to the region. An upper level
trough sinking southward over the islands is responsible for the
unstable airmass, allowing trade wind showers to be more intense
than normal. In addition, this instability could trigger a
few thunderstorms.

This set up over the next couple of days will continue the wet
trade wind weather with the potential for moderate to locally
heavy rain focused windward and mauka, particularly over the
western end of the state through early Tuesday morning and the
Big Island and Maui Tuesday and Wednesday.

The Winter Storm Warning remains in effect through Tuesday night
for the Big Island, with the primary concern being freezing rain
leading to ice accumulation.

As the above mentioned upper level trough lingers over the
islands, a couple more rounds of moderate to locally heavy rain
potential exist both Tuesday night and Wednesday night. In both
cases, the focus is expected to be mainly over Maui and the Big
Island, but can't completely rule out Oahu and Kauai from seeing
additional showers.

Trade winds will linger through the week with high pressure to the
north. Winds are expected to increase mid-week so the above
mentioned surface trough dissipates. Toward the end of the week,
the high will move to the east, and be replaced by a new high,
which will maintain the moderate to locally windy trade winds.

From Thursday on into the weekend the upper level trough lifts to
the north and northeast, just enough to cut off some of the
instability that is leading to the heavier showers. As such look
for a return to a more typical trade wind pattern.

&&

.AVIATION...
Moderate to breezy trade winds will persist for the next several
days as surface high pressure builds north of the state. Clouds
and showers will favor windward slopes and coasts.

A deepening upper level trough will enhance convective activity.
There is a slight chance of thunderstorms statewide through forty-
eight hours and possibly beyond.

Periods of MVFR conditions with low ceilings and visibility in
showers are expected mainly over windward airfields, especially
tonight with the heaviest rainfall is expected over windward Big
Island.

AIRMET Sierra for mountain obscuration has been reissued
for east facing slopes of the Big island. Conditions are expected
to persist through tomorrow morning and could spread to the
smaller islands later tonight.

AIRMET Tango is in effect for moderate leeward mountain wave
turbulence over all islands due to breezy trade winds, and will
continue through at least Tuesday. In addition, a portion of the
subtropical jet over the state will continue to cause areas of
moderate turbulence aloft over the eastern half of the state
tonight.

&&

.MARINE...
A strong high pressure system will drift eastward, slowly passing
north of Hawaii over the next few days. Expect strong to near-
gale east-northeast trade winds through much of this week as
another strong high pressure system moves into the region from the
west just as the first one departs the region towards the east. A
Small Craft Advisory is in effect for all waters, and will likely
remain in place through much of this week. A persistent trough
aloft will keep the island atmosphere unstable, with briefly heavy
showers producing periods of strong wind gusts and low
visibility. Isolated thunderstorms are also in the forecast into
Thursday.

The persistent trade winds will generate rough and choppy surf along
east facing shores through the week. Gradually diminishing
medium period swells out of the northwest and north will continue
to trend down through Tuesday. A small, medium period northwest
swell will arrive on Wednesday. Followed by a larger and longer
period northwest swell, building surf heights to near advisory
thresholds along exposed north and west facing shores from Friday
to Saturday.

South shores will remain seasonably small with mainly medium
period background swell energy pulses.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM HST Wednesday for Big Island
Summits.

Small Craft Advisory until 6 AM HST Thursday for all Hawaiian
waters-

&&

DISCUSSION...M Ballard
AVIATION...Bedal
MARINE...Bohlin