Pearl City, Hawaii 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

936
FXHW60 PHFO 112000
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
1000 AM HST Wed Dec 11 2024

.SYNOPSIS...
Strong trades will focus showers over windward and mauka areas
through tomorrow, particularly for the eastern end of the state.
Trades then ease for the weekend and into next week with limited
shower activity.

&&

.DISCUSSION...
At the surface, broad high pressure is expanding far north of the
islands. Meanwhile, a trough associated with a well-defined low
aloft is making its way westward, well south of the state. This
trough and its associated upper low are supporting an area of
widespread showers and a few thunderstorms about 350 miles south
of the Big Island. Closer to Hawaii, morning radar and satellite
imagery shows isolated to scattered showers moving into windward
and mauka locations, particularly for the Big Island, which is
located closer to the trough and well-defined upper low to the
south. Temperature inversion heights from the 12z Lihue and Hilo
upper air soundings are high enough to allow for some showers to
spill over to leeward areas at times. Looking upstream, isolated
to scattered showers will remain possible into early afternoon,
but should trend down for most of the smaller islands while
remaining focused primarily on the eastern end of the state.

As previous discussions have mentioned, the main focus for the
forecast continues to be the strengthening trade winds today in
response to the high pressure ridge building to our north and the
low aloft south of the islands that is deepening and migrating
westward. Latest hi-res guidance and ensembles align with the
current forecast philosophy that winds will generally peak today
through tonight at breezy to strong levels, then begin to decline
later Thursday through the rest of the week. A Wind Advisory
remains in effect through tonight for the typically windier areas
of the Big Island and portions of Maui County. While it will be
breezy for Kauai, Oahu, and Molokai today as well, the pressure
gradient will be strongest over the eastern end of the state.
Therefore, will hold off on expanding the Wind Advisory westward
at this time. A High Wind Warning for the Big Island Summits
remains in effect through 6 PM HST today, and observations from
this morning continue to confirm winds well into warning levels.
Summit winds will remain elevated tonight, so the High Wind
Warning may need to be extended in time or converted to a Wind
Advisory for tonight.

For the next couple of days, the fairly dry and stable breezy trade
wind pattern will persist for the western end of the state, while
slightly higher shower chances can be expected over the eastern
end. This will be due to a combination of the proximity of the
upper level low moving westward to our south and deeper moisture
edging up from the south near the Big Island. By the weekend and
early next week, trade winds will not be as strong as the low
south of the island dissipates and a series of fronts passing to
our north weaken the surface ridge. In addition, drier air will
filter across the region, putting a damper on trade wind showers
throughout this period.

&&

.AVIATION...
AIRMET Tango remains in effect for low-level turbulence to the
lee of the mountains across the state and for strong surface winds
east of Molokai. Both elements of this AIRMET will likely be
needed into Thursday due to strong high pressure north of the
islands and associated blustery trade winds. In addition, we will
be monitoring the situation over the next few hours to determine
if an upper level AIRMET Tango is needed.

Clouds and showers riding in on the trades will continue to focus
rainfall over windward sides of the islands, with isolated MVFR
conditions. At this time no widespread mountain obscuration is
expected.

&&

.MARINE...
High pressure north of the Hawaiian Islands will keep strong
trade winds in place today before gradually easing to fresh by
Friday into the weekend. The Gale Warning for Maalea Bay, the
Pailolo and Alenuihaha Channels, and waters south of the Big
Island will remain in effect through tomorrow afternoon. A Small
Craft Advisory is in effect for the remaining waters where winds
will still be fresh to strong and seas are expected to remain near
10 feet.

Surf along north and west-facing shores have been lowering this
morning and will continue to lower through the day. North and
west shore surf will remain elevated through Friday then decline
over the weekend.

Surf along east-facing shores will increase slightly tomorrow and
remain rough and choppy through the Friday due to the fresh to
strong trade winds.

Surf along south-facing shores will remain small, although small
southeast bump in surf is possible lather today through tomorrow
for windward Big Island due to a small southeast reinforcement,
This will have little effect elsewhere.

&&

.FIRE WEATHER...
Gusty trades will be accompanied by drier air moving over the
islands today. While afternoon relative humidity (RH) values may
briefly dip below 50%, the probability of reaching Red Flag
Warning criteria continues to be low. Therefore, no fire weather
headlines are in effect and none are anticipated at this time.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 6 AM HST Thursday for Lanai Mauka-Kahoolawe-
Maui Windward West-Maui Leeward West-Kohala-Big Island Interior-
Lanai Windward-Lanai Leeward-Lanai South-Maui Central Valley
North-Maui Central Valley South-South Haleakala-Big Island South-
Big Island Southeast-Big Island North.

High Wind Warning until 6 PM HST this evening for Big Island
Summits.

Small Craft Advisory until 6 PM HST Thursday for Kauai Northwest
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Windward Waters-Oahu Leeward Waters-Kaiwi Channel-Maui
County Windward Waters-Maui County Leeward Waters-Big Island
Windward Waters.

Gale Warning until 6 PM HST Thursday for Maalaea Bay-Pailolo
Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island
Southeast Waters.

&&

$$

DISCUSSION/FIRE WEATHER...Vaughan
AVIATION...Powell
MARINE...Tsamous