527 
FXHW60 PHFO 020125
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
325 PM HST Thu Sep 1 2022

.SYNOPSIS...
Moderate trade winds will continue through the first part of the 
holiday weekend, strengthening somewhat Sunday into Monday. The 
lighter winds will allow afternoon sea breezes to develop over 
leeward areas, which may lead to some clouds and a few showers. 
Otherwise, expect clouds and showers to favor windward areas, 
especially on Saturday and on Labor Day, as areas of increased 
moisture move through. 

&&

.DISCUSSION...
High pressure far N of the area will support a trade wind flow over 
the islands for the foreseeable future, with winds potentially 
trending a little stronger late this weekend and early next week. In 
the short term, a stalled front several hundred miles N of the 
islands will keep winds in the moderate range. This may allow 
afternoon sea breezes to drive cloud and shower formation over 
leeward portions of the smaller islands, while leeward Big Island is 
virtually guaranteed to see daily afternoon clouds/showers over the 
slopes. While little in the way of clouds formed over leeward Oahu 
this afternoon, there remains a chance that sea breeze convection is 
a little more vigorous Friday and Saturday. Otherwise, the trade 
winds will deliver low clouds and a few showers to windward slopes 
and coasts. Afternoon soundings show a very strong inversion around 
7000-8000 feet, supported by a nearby strong mid-level ridge that is 
limiting rainfall intensity.

Trade winds may trend a little stronger later this weekend as the 
front N of the area dissipates. Locally breezy conditions are 
possible, but the high to the N will not be particularly strong. The 
strong mid-level ridge will weaken as a mid-level trough passes just 
N of the islands this weekend, but this is not expected to result in 
significant destabilization of the island atmosphere. Global models 
indicate an area of increased low-level moisture (currently between 
140W and 150W) moving over the islands Friday night and Saturday, 
likely bringing a modest increase in windward showers. After some 
drying Sunday, guidance indicates another area of increased moisture 
arriving from the E on Monday. Longer range guidance indicates a 
trend toward lighter winds after the middle part of next week. 

&&

.AVIATION...
Moderate trade winds will continue over the next few days, with 
localized afternoon sea breezes over some leeward areas. VFR 
conditions will prevail for most areas for the next 24 hours, with 
only brief MVFR conditions possible for windward and mauka locations 
in passing trade showers.

AIRMET Sierra for mountain obscurations over the windward sections 
of the Big Island has been cancelled as conditions have improved.

&&

.MARINE...
Moderate to locally fresh trade winds will prevail through much of 
the week. A diffuse front sitting about 175 nm north of Kauai and 
Oahu is weakening the local pressure gradient over the state. As the 
front dissipates over the next couple of days, surface high pressure 
to the north will erode, resulting in little change in local winds. 
Trades may strengthen late Sunday and Monday as high pressure 
briefly builds to the north.

No significant surf is due this week. The current, small south swell 
will fade late Friday, with a small pulse of south- southwest swell 
possible this weekend. A storm expected to develop south of New 
Zealand during the next few days will likely send a larger south-
southwest swell to Hawaii for the following weekend. Small, short 
period northerly swells will produce periods of tiny north shore 
surf this week, and east shore surf will remain well below seasonal 
average through the week.

&&

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

&&

$$

DISCUSSION...Birchard 
AVIATION...TS 
MARINE...Wroe