Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 290419 CCA
Area Forecast Discussion
National Weather Service Honolulu HI
353 PM HST THU JUL 28 2016
Corrected grammar and spelling
Breezy trade winds will persist through tomorrow as high pressure
remains to our north. Trades are forecast to decrease slightly this
weekend as a low aloft and a weak surface trough approach from the
east. Clouds and showers will favor windward and mauka areas.
Showers may become more active this weekend through early next week.
A 1030 MB surface high located at 41N144W is driving fresh to strong
trade winds across the state this afternoon. Soundings show a dry
and stable atmosphere across the state with strong inversions at
4500 to 6000 feet. Precipitable water values are on the low side
around 1.1 inches. Visible satellite imagery shows partly to mostly
cloudy skies windward and mostly sunny skies leeward (with the
exception of afternoon cloud build-ups on the Kona slopes). In the
short term, expect stable and breezy conditions to continue with
An upper low and associated weak surface trough will approach from
the east on Friday. The trades may strengthen slightly and back
northeasterly ahead of the surface trough on Friday. This weekend,
an increase in low level moisture is expected to arrive as the
trough axis moves by with weakening and veering winds. This will
result in a wetter trade wind pattern from this weekend into early
next week. Clouds and showers will still favor windward and mauka
areas, but leeward areas will see more showers than they do now.
AIRMET TANGO remains in effect for low level turb over and S through
W of the mountains. The 200 PM soundings showed a strong inversion
sloping from 6200 feet at Hilo to 4300 feet at Lihue while the VAD
wind profiles show 20 to 30 kt winds in the lower atmosphere.
VFR conditions will prevail, but windward areas may experience
isolated MVFR ceilings.
A high to the northeast will maintain strong to near-gale force
trade winds across the area through Friday. A Small Craft Advisory
(SCA) is in effect for all Hawaiian waters through Friday afternoon.
Winds will taper off as a weak surface trough arrives from the east
Friday night into Saturday. Some or all zones may drop out of the
SCA this weekend.
The trade winds will produce choppy surf along east facing shores,
but surf heights are expected to remain below advisory levels. There
will be a series of small south swells into next week but surf will
remain below the advisory level alon south facing shores. Only small
surf is expected along north and west facing shores.
Small Craft Advisory until 6 PM HST Friday for all Hawaiian