Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 270654
Area Forecast Discussion
National Weather Service Honolulu HI
830 PM HST FRI AUG 26 2016
Locally breezy trade winds will continue through early next week as
high pressure persists north of the islands. Passing low clouds and
brief showers will favor windward and mauka areas during nights and
mornings. An increase in trade wind showers is expected from late
Saturday through Monday. Weather may become more active, with
potentially an increase in winds by the middle of next week, as the
islands may experience the effects from Tropical cyclone Madeline.
A surface high far north-northeast of the state continues to bring
moderate to locally breezy ENE trade winds to the islands. Low
clouds with embedded showers carried by the winds are reaching the
islands at times, affecting mainly windward areas. The exception is
Kona side of the Big Island, where evening convection has developed
along the coast, bringing localized heavy rain. Believe the
convection may last for another hour or so before dissipating.
The center of the aforementioned high will hover around the same
area over the weekend, then slowly moves south by early next week.
As such, trade winds will prevail across the state through early
next week. Latest forecast models continue to show possibly an area
of moisture reaching the islands from the northeast during the later
part of the weekend into early next week. This may result in an
increase in showers later on Saturday through Monday.
After this moisture departs west of the islands, the next area of
moisture in the trade flow is possible Tuesday through Thursday
as Madeline approaches the area from the E. The latest official
forecast from the National Hurricane Center (NHC) in Miami indicates
that Madeline will be nearing the Big Island around the middle of
next week. While uncertainty on the scenario remains high at this
point, it does highlight the potential for tropical cyclone
conditions impacting in the islands. Continue to monitor the
forecast in the coming days as changes are almost expected. It is
still expected that Madeline will cross 140W into the central
Pacific some time Saturday, after which the Central Pacific
Hurricane Center in Honolulu will take over the responsibility of
issuing advisories. Additional unsettled weather associated with
Tropical Cyclone Lester may arrive over Labor Day holiday weekend,
but this is extremely uncertain at this time.
VFR will prevail...but low-level NE winds will carry enough clouds
and showers over the other islands to produce isolated MVFR
conditions over windward areas. There could be enough MVFR to
require AIRMET SIERRA for MTN OBSC at times over the next 24 hours.
Otherwise, no AIRMETs or SIGMETs are expected.
A Small Craft Advisory (SCA) is in effect for waters around Maui
county and the Big Island, due to locally breezy trade winds
accelerating around the high terrain. Winds may briefly and slightly
ease a little on Saturday, only to firm up a little Sunday and Monday.
Believe wind speeds will remain high enough to warrant the SCA
No significant swells are expected through the middle of next week,
though surf along E facing shores will be slightly elevated due to
the stronger trades. Winds and seas, as well as surf along E facing
shores, may increase toward the middle and end of next week due to
the possible effects from Tropical Cyclones Lester and Madeline.
There is still quite a bit of uncertainty on the scenario as the
situation is developing.
Small Craft Advisory until 6 PM HST Sunday for Maalaea Bay-Pailolo
Channel-Alenuihaha Channel-Big Island Leeward Waters-Big Island