Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 290153
Area Forecast Discussion
National Weather Service Honolulu HI
353 PM HST THU JUL 28 2016
Breezy trade wind weather will persist through the work week as
high pressure builds far to our north. Trades are forecast to
decrease slightly this weekend as an upper low and associated
weak surface trough approaches from the east. Clouds and showers
will favor windward and mauka areas, but may become more active
this weekend through early next week.
A 1030 MB surface high is 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 shows partly to
mostly cloudy skies windward and mostly sunny skies leeward (with
the exception of afternoon cloud ups on the Kona slopes). In the
short term, expect stable and breezy conditions to continue with
little rainfall carrying in with the trades.
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 for low level turb over and S through W of the
mountains remains posted as breezy NE to E trade winds continue.
The 12Z soundings from PHTO and PHLI show a strong inversion
sloping from 6.2 kft to 4.3 kft, respectively.
Expect primarily VFR conditions throughout the islands tOnight.
The relatively dry atmosphere and strong inversion will help keep
showers at a minimum. A large area of stable stratocumulus extends
from the coast of California to near Hawaii. The breezy trade
winds will help carry some of these low stable clouds towards the
islands and windward areas may experience isolated MVFR cigs.
A high pressure system far northeast of the state will maintain
breezy 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 result in choppy, short-period surf along
east facing shores, but surf heights are expected to remain below
advisory levels. There will also be a series of small southerly
swells through the weekend and into next week.
Small Craft Advisory until 6 PM HST Friday for all Hawaiian