Area Forecast Discussion
Issued by NWS Honolulu, HI

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000
FXHW60 PHFO 211939
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
939 AM HST Thu Mar 21 2024

.SYNOPSIS...

Breezy northeast trade winds will persist for the next couple of
day before becoming more easterly this weekend through early next
week. Clouds and showers will favor windward and mauka locations
as areas of moisture move through.

&&

.DISCUSSION...

Guidance remains well aligned with the current pattern. Northeast
trade winds will increase to breezy levels today and then veer
more easterly over the weekend as a surface high pressure
strengthens north of the region and then tracks eastward. Showers
will favor windward and mauka areas, which is the case this
morning over the eastern end of the state, where an area of
moisture has moved in from the east. Rainfall totals for the past
12 hours along some windward Big Island stations measured between
.11 of inch to .50 inches. Later tonight through Saturday, a weak
pulse aloft and a shallow band of low- level moisture will drop
southward into the area, potentially leading to an uptick in
shower coverage with gusty winds. Guidance indicates a trend
towards an increase in moisture early next week, with precipitable
water values rising to around 1.5 inches along with a mid-level
trough moving in from the southeast. Should this scenario unfold,
anticipate a more pronounced uptick in shower coverage over
windward areas, while breezy trade winds persist.

&&

.AVIATION...
Moderate to locally breezy trade wind flow will prevail, and
AIRMET Tango has been issued for low-level turbulence. Clouds and
showers are most prevalent over Maui and Hawaii Counties this
morning, where AIRMET SIERRA is posted for mountain obscuration.
Some general clearing is expected this afternoon, mostly over
windward Maui and Molokai, with showers to continuing to pepper
windward Big Island skies into Friday. Isolated showers will
prevail elsewhere, but an area of increased showery low clouds
will likely move over windward Kauai and Oahu tonight and Friday.

&&

.MARINE...
Surface high pressure north of the state will slowly strengthen
and drift east through Saturday. Trade winds will strengthen to
moderate to locally strong through the weekend. The Small Craft
Advisory (SCA) is in effect for the typically windier waters near
Maui County and the Big Island through Friday, with the potential
for additional zones to be included as the stronger trades become
more widespread Friday into Saturday.

The current moderate northwest (310-320 degree) swell will keep surf
elevated today but gradually decline through Friday. A new reinforcement
small to moderate long period northwest (310-320 degree) swell,
is expected to arrive late Friday with another slightly larger
reinforcement from the same direction Sunday night and Monday.
This late weekend swell will likely result High Surf Advisory
level criteria for exposed north and west facing shores.

Surf along south facing shores will return to background levels
for the next several days. Short period trade wind swell will be
below seasonal average through today and will likely pick up
Friday through the weekend as trade winds increase.

&&

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

&&

$$


DISCUSSION...Almanza
AVIATION...Birchard
MARINE...Foster


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