Current Conditions
Temp7.7 C
RH8 %
WindNNE 16 mph
RoadOpen (4x4)
Menu of Text Products for the Hawaiian Islands and the Tropical Pacific/Atlantic Oceans:
Narrow the Menu List
Select Time Limit: 12 hours | 24 hours | 48 hours | 72 hours | No time limit
Select Product Type: All | Routine Bulletins/FCSTS | Warnings/Watches/Advisories | HAWN Weather | Tropical | Marine | Aviation | Daily Obs | Special
Hawaiian Islands Synoptic Discussion and Guidance

238
FXHW60 PHFO 300137
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
337 PM HST Wed Jun 29 2022

.SYNOPSIS...
Surface high pressure is centered far north of the area. This
places the islands in a moderate to breezy trade wind environment.
A few passing showers can be expected mainly over windward and
mauka areas. An upper level trough will pass across the area from
east to west Saturday and Sunday with an uptick in showers
expected especially for windward and mauka areas. A drier trade
wind weather pattern is then expected Monday through Wednesday.

&&

.DISCUSSION...
Surface high pressure is centered far north of the area placing
the islands in a moderate to breezy trade wind environment. A
ridge axis aloft is keeping the airmass rather stable with
inversion heights between 7,000 and 7,500 feet. Moisture embedded
in the trades is providing for passing showers over windward and
mauka areas with most leeward locations remaining dry. Daytime
heating has caused clouds and few showers to form over the Kona
slopes this afternoon. Some thin high clouds will occasionally
move over the area from time to time in southwesterly flow aloft.
Little change in this weather pattern is expected through Friday.

As we head into the weekend, a trough aloft is forecast to be near
the Big Island on Saturday, then pass from east to west across the
state Saturday night through Sunday night. This will likely
destabilize the airmass a bit across the area. Shower activity is
expected to increase with most showers falling over windward and
mauka areas. The trade winds will be sufficiently strong enough
for some brief passing showers to fall over select leeward areas
at times. There may also be some increase in showers over the Kona
slopes during the afternoon and evening hours with a few locally
heavy downpours possible.

The upper trough is expected to be west of the area Monday and
Tuesday with a drier trade wind weather pattern expected. Little
change is expected on into Wednesday.

&&

.AVIATION...
Moderate to breezy easterly trade winds will continue across the
state at least through Friday. As a result, low clouds and
showers will favor north through east facing sections of the
islands with isolated showers spilling over into leeward areas
from time to time. The best chance for showers will be during the
late night and early morning hours. VFR flight conditions are
expected to prevail at most locations, though MVFR ceilings and
visibilities will remain possible within any showers that develop.
On the Big Island, cloud coverage that has increased across the
leeward slopes this afternoon during peak heating should diminish
late tonight into early Friday morning.

AIRMET Tango remains in effect for moderate low-level turbulence
downwind of the higher terrain of all islands. This AIRMET is
likely to persist through the next few days.

&&

.MARINE...
Fresh to strong trade winds will continue over the next couple of
days. Trades will become stronger Friday through the weekend as
the driving high pressure system to the north strengthens. Seas
will respond and become rough, potentially reaching the 10 ft
Small Craft level over the waters south of the Big Island and in
the Alenuihaha Channel by the weekend. Winds may weaken slightly
early next week.

Surf along south facing shores will hold near the advisory level
through tonight, then ease Thursday and Friday. Surf along east
facing shores will steadily trend up through the second half of
the week as the local and upstream trades strengthen. This will
result in rough conditions for easterly exposures Friday through
the weekend. Confidence remains low for any long-period pulse
locally associated with former Tropical Cyclone Celia in the far
eastern Pacific.

Surf along north facing shores will remain at seasonal levels
(near flat) through the weekend.

&&

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

&&

$$

DISCUSSION...Burke
AVIATION...Vaughan
MARINE...Foster

Bulletins, Forecasts and Observations are courtesy of Honolulu National Weather Service Forecast Office