Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 251927
Area Forecast Discussion
National Weather Service Honolulu HI
927 AM HST THU AUG 25 2016
Trade winds will return today as high pressure persists to our
north and troughing to our west continues to move away. Trade
winds will become locally strong as clouds and showers favor
windward and mauka areas through early next week. A pair of
tropical cyclones expected to move westward across the central
Pacific may affect the main Hawaiian Islands beginning late next
week, possibly bringing more active weather.
Deep troughing along 170W, to the west of the main Hawaiian
Islands, has moved far enough away to allow trade winds to begin
building westward across the state this morning. By this
afternoon, high pressure to our north will cause trade winds to
strengthen to locally strong across the traditionally windy waters
around Maui and the Big Island, and a Small Craft Advisory is in
effect for those marine zones. Dewpoints should drop statewide and
our airmass should stabilize, causing a decrease in shower
activity compared to the last few days. As trade winds take hold,
clouds and showers will revert to a more familiar pattern,
favoring windward and mauka areas.
We expect the high to our north will keep moderate to locally
strong trade winds in place, along with more comfortable humidity
levels and fewer showers, through early next week. Beginning late
next week, models show that a pair of tropical cyclones moving
westward across the central Pacific may affect the island chain.
However, it`s still too early to tell what, if any, impacts could
be seen in Hawaii. The National Hurricane Center in Miami is
tracking these systems now, but the first of these systems could
cross 140W into the Central Pacific Hurricane Center`s area of
responsibility as early as Sunday.
VFR conditions will occur mostly across the terminals today as
northeasterly trade winds prevail. Trade wind showers will be
most likely for the windward and mountain areas, with isolated
MVFR showers possible there.
AIRMET TANGO remains in place with the possibility of moderate low-
level turbulence. Model soundings indicate that any turbulence
will be below an inversion around 5-6 kft across the terminals
A Small Craft Advisory is in effect for the traditionally windy
waters around Maui and the Big Island, thanks to strengthening
trade winds. This advisory is in effect through Friday afternoon,
but will likely have to be extended in some form through the
Short period trade wind swell will increase surf slightly along
eastern facing shores Friday and into the weekend. Otherwise, no
significant surf is expected through early next week. By the
middle of next week, long period easterly swell generated by
potential tropical cyclone activity east of Hawaii may begin to
affect the state.
Small Craft Advisory until 6 PM HST Friday for Maalaea Bay-
Pailolo Channel-Alenuihaha Channel-Big Island Leeward Waters-Big
Island Southeast Waters.