Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Honolulu HI
1000 am HST Friday Jul 3 2015
light winds...with land and sea breezes...will continue today
with clouds and a few showers over the interior of the islands
mainly during the afternoon. Light trade winds will return for the
weekend...but will remain light enough for localized land and
sea breezes. Expect trade winds to slowly reach back to moderate
levels by the middle of next week.
a surface ridge remains over the islands this morning...keeping
light winds at the surface. The synoptic...or background flow...is
from the southeast to east near Maui County an The Big Island...and
from a more southerly direction near Kauai based on the low cloud
motion on satellite imagery. Satellite also showed an area of
cloudiness to the south of Oahu at daybreak...but since then this
area has begun to dissipate as the clouds moved over the Kauai
The light winds today will continue to bring widespread land and sea
breezes...which will also continue to bring warm and humid
conditions to the islands. The front to the north northwest of the
islands will continue to lift north today...allowing the ridge to
lift north which should help light trades to return to the islands
Saturday and Sunday. Winds will remain light enough however that
localized land and sea breezes will still set up...but in general
there should be more air movement that over the last couple of days.
Heading into the new work week...the ridge will linger north of the
islands...maintaining light trades over the islands that will
increase to moderate levels by middle week. The strengthening of the
trades will be due to the ridge being reinforced with a new high to
the north on Tuesday...coupled with a couple of lows to the south of
the islands...that will increase the pressure gradient over the
As the background flow turns the east Saturday...and then a little
more northeasterly by Monday...expect showers to become focused
again over the windward and Mauka areas. As the trades return in
ernest during the work week...expect a more typical trade wind
The GFS and European model (ecmwf) are both in agreement with the development of some
lows to the south and southeast of the islands next week. However
its unlikely that each of the systems that the models are currently
locking onto will develop. Will be monitoring future runs to see
which scenario will pan out.
light flow associated with a ridge over the islands will allow for
sea breezes to form later this morning. Interior areas can expect
clouds and scattered showers to pop up this afternoon. On The Big
Island and Maui County...excluding Lanai...cloud tops should mainly
stay below 120 with predominately VFR cigs/vis. On Lanai...MVFR and
isolate IFR ceilings are likely to linger until evening. A patch of
moisture near Oahu and Kauai will aide in enhancing afternoon
showers over the Western Islands. Kauai and Oahu may see towering cumulus tops
between 150 and fl200...some showers may introduce periods of MVFR.
Showers mentioned above will begin to scatter out with sunset and as
the land breeze develops.
Small Craft Advisory conditions are not expected through the Holiday
weekend...but could develop in the windier marine zones next week by
Tuesday as the trades build.
The current south swell will continue to decline today...but another
bump is expected Saturday night and Sunday...and could bring the
south shores surf near advisory levels.
The current northwest swell will gradually decline through the
weekend. Another small northwest bump may arrive on Monday night.