Drought in Hawaii, July 1 to 31, 2020

Area Forecast Discussion
National Weather Service Honolulu HI
820 PM HST Tue Jun 30 2020

.SYNOPSIS...
Locally breezy trade winds and rather dry and stable conditions
will prevail through Wednesday. Trades will drop a notch on
Thursday as high pressure weakens far north-northeast of the
state. A typical, summertime trade wind weather pattern will then
dominate into early next week, focusing showers over windward
slopes with clouds and showers forming on leeward Big Island each
afternoon.

&&

.DISCUSSION...
Currently at the surface, a 1033 mb high centered around 1900
miles north-northeast of Honolulu is driving moderate to locally
breezy trade winds across the island chain this evening. Infrared
satellite imagery shows partly cloudy skies in most areas, with a
few pockets of more extensive cloud cover in some windward locales
as well as leeward sections of the Big Island. Radar imagery shows
very little shower activity, and all rainfall gages have reported
no rain in the past 6 hours. Main short term concern revolves
around trade wind trends.

High pressure north-northeast of the state will keep moderate to
locally breezy trades in place through Wednesday evening, the
trades will drop off a bit by Thursday as the high driving the
trades locally weakens. Light to moderate trades will then hold in
place through the Holiday weekend, before trending back to
moderate and locally breezy levels early next week.

Trade wind weather will prevail during the next 7 days, with
showers favoring windward and mauka areas along with the stray
leeward spillover. Showers will be most common at night and in
the early morning hours. Rather dry conditions will prevail
through Thursday, before an uptick in moisture and a weak mid-
level shortwave trough leads to a slight increase in shower
activity Friday through the Holiday weekend. A few leeward
showers may develop each afternoon as a result of daytime heating
in the lighter trade wind regime Thursday through Sunday, while
scattered showers will form each afternoon through the forecast
period over leeward Big Island. More typical trade wind weather
appears to return early next week.

&&

.AVIATION...
High pressure north of the islands will keep moderate to
locally breezy trades in place across the islands tonight.
Isolated showers, caught up in the trade flow, will mainly occur
along the windward coasts and slopes. Expect brief periods of MVFR
conditions, but not expecting anything widespread.

AIRMET Tango is in effect for moderate low level turb below 7 kft
over and downwind of the terrain of all islands. No other AIRMETs
are in effect.

&&

.MARINE...
Fresh to strong easterly trades will continue through Wednesday,
then trend down into the moderate to fresh category Thursday through
the Holiday weekend. Strongest winds are expected in the Pailolo
and Alenuihaha Channels, Maalaea Bay and waters around South Point
of the Big Island - where a Small Craft Advisory remains in place
through late Wednesday afternoon. Seas across the Alenuihaha
Channel and waters south of the Big Island will remain just below
the advisory level (10 ft) through Wednesday before easing through
the second half of the week.

Surf along south facing shores will remain up due to the recent
active pattern across the southern Pacific within Hawaii's swell
window. As the current south swell continues to lower through
midweek, a new long-period, south swell is expected to arrive
through the day Wednesday and should be fully filled in by
Thursday. This will hold into Friday, then lower into the weekend.
For the upcoming weekend, a mix of small background swells out of
the south-southeast and south-southwest is expected.

Surf along east facing shores will remain small through Wednesday,
then trend up slightly Thursday through Friday as a 8-9 second
period, east-northeast wind swell arrives. A downward trend is
anticipated over the weekend.

Surf along north facing shores will remain near the summertime
average each day - exception being at the locations exposed to trade
wind energy wrapping in. A small, medium period northwest swell will
be possible over the weekend (2 ft 12 sec).

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Wednesday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.

&&

DISCUSSION...Jelsema
AVIATION...Thomas
MARINE...Gibbs