Area Forecast Discussion for Hawaii

Area Forecast Discussion   Issued: 07/10/2026 04:17:00 PM UTC

                        
766
FXHW60 PHFO 100617
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
817 PM HST Thu Jul 9 2026

.SYNOPSIS...
Strong high pressure far north of the state will continue to
produce breezy trades into the weekend. One batch of trade wind
showers will spread across mainly Maui and the Big Island tonight
with a quick downpour or two possible windward. Another increase
in moisture will bring enhanced showers to mostly windward and
mauka locations Saturday night into Sunday. Otherwise fairly
typical trade wind weather is expected.

&&

.SHORT TERM UPDATE...
There have been some decent 3 hr rainfall amounts over an inch
over portions of windward Big Island. Overall the forecast is on
track tonight so no updates are expected.


&&

.PREV DISCUSSION...
Issued at 331 PM HST Thu Jul 9 2026
Very large surface high 1035 mb or so meanders over the far NE
Pac the next 10 days, keeping trades breezy with slight slackening
expected by the middle of next week. One batch of enhanced
showers is rolling into Maui and the BI, associated with higher PW
around 1.75" moving in...enough for a couple of quick windward
and mauka downpours. Oahu should be on N fringes of this moisture
convergence later tonight and Fri AM. Still another shower area
progged near the islands in the ensemble means Sat night into Sun
AM. Ridging persists aloft, so nothing too unusual expected with
either of these. Otherwise, typical windward and mauka showers
expected with PW trending near normal thru midweek next week.

However...the latest ensemble runs and current MJO phase suggest
we keep an close eye on the tropics to our S and SE the over the
next couple of weeks. There is more agreement in the long range
than I`d like to see, that the ITCZ to the S and SE of the islands
will become even more active. The subtropical jet shifts N of the
islands in a week or so, anticyclonic flow builds aloft SE of the
islands, and deeper tropical moisture and much- below- normal
surface pressure gradually get established to our S and shift
northward. Just a little tap on the shoulder to remind us that
while it is quiet over the islands for the time being, we are
getting farther into Hurricane Season with what is expected to be
a very strong El Nino continuing to build.

&&

.AVIATION...

Moderate to breezy trades will persist across the Hawaiian
Islands, bringing in pockets of enhanced low-level showers across
predominately windward and mauka areas, occasionally spilling over
into leeward areas. Expect VFR conditions to prevail across most
locations, with occasional localized MVFR/IFR conditions in
association with shower activity.

AIRMET Sierra is in effect for mountain obscuration above 2500
feet for windward Kauai, Oahu, Maui, and the Big Island. This is
expected to persist throughout the period as shower activity
continues, even if showers prove to be intermittent at times.

AIRMET Tango remains in effect for moderate low-level turbulence
over and downwind of terrain for all islands. This AIRMET will
likely continue through the next several days.


&&

.MARINE...
Issued at 331 PM HST Thu Jul 9 2026
Strong high pressure centered north of the state will remain
nearly stationary over the forecast period driving fresh to strong
trade winds across the entire coastal waters. The Small Craft
Advisory (SCA) is in effect through Friday afternoon for all
Hawaiian waters. Trades will remain fresh to strong through the
weekend so the SCA may need to be extended but a few leeward zones
might drop off.

The current small medium-period south-southwest (190-200 degrees)
swell will gradually decline through Friday. A small to moderate,
long- period southwest swell (220 degrees) is expected to fill in
Saturday into early next week, but due to its Tasman source,
could be more inconsistent than the current swell.

Surf along east-facing shores will remain rough and choppy
through the forecast period as fresh to strong trades hold. A
series of small, moderate- to long-period west (270 to 280
degrees) swells are expected to arrive late Friday and hold into
early next week, sourced from Typhoon Bavi in the far western
Pacific. Surf along north-facing shores is expected to remain flat
to tiny with no significant swells forecast from the north or
northwest.

Looking ahead, higher than normal high tides will be possible
beginning during the latter half of this weekend. Interests
immediately along the coasts in low-lying or vulnerable areas
should continue to monitor forecasts for possible coastal flooding
due to the King Tides from Sunday through the first half of next
week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 PM HST Friday for Alenuihaha
Channel-Big Island Leeward Waters-Big Island Southeast Waters-
Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai
Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters-
Maalaea Bay-Maui County Leeward Waters-Maui County Windward
Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.


&&

$$

SHORT TERM UPDATE...Tsamous
DISCUSSION...R Ballard
AVIATION...Pierce
MARINE...Shigesato