Area Forecast Discussion
Issued by NWS Honolulu, HI

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174
FXHW60 PHFO 281353
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
353 AM HST SAT MAY 28 2016

.SYNOPSIS...
A weak front northwest of the state will keep winds light through
the weekend. This front will push slowly southward through Kauai
and Oahu Sunday night and Memorial Day, before stalling out and
dissipating over the central and eastern islands by mid week. High
pressure will build north of the state in the wake of the front,
allowing the trade winds to return for much of next week.

&&

.DISCUSSION...
Currently at the surface, a 1027 mb high is centered around 1550
miles northeast of Hilo. Meanwhile, a nearly stationary front
resides around 325 miles northwest of Kauai. Infrared satellite
imagery shows partly to mostly cloudy skies in place over the
islands, with radar imagery showing scattered showers drifting
through the area. Main short term concern for today revolves
around rain chances.

Today through Sunday...
The front northwest of the islands will push slowly southeastward
through the period, and will be approaching the coast of Kauai by
late Sunday afternoon. As a result, a light wind regime will
remain in place across the state, with daytime sea breezes and
overnight land breezes expected in most areas. Precipitable water
(PW) values will remain around 1.5 inches through the period, so
expect scattered to numerous showers over the interior of the
islands each afternoon/evening with lesser activity during the
overnight and early morning hours.

Sunday night through next Friday...
The 00z GFS and 00z ECMWF offer slightly different solutions with
respect to the front or its remnants entering the island chain
early next week. Despite the minor differences in timing details,
they both suggest that a weakening front will move southward
through Kauai and Oahu early next week. The front or its remnants
will then slowly dissipate over the central and eastern islands
through mid week as high pressure builds north of the state. We
will utilize a blend of the 00z solutions through the period which
suggests some enhanced showers moving southward through the island
chain in association with the weakening front on Memorial day and
through the first half of the week. Showers should also begin to
focus more across windward and mauka locales as the week
progresses due to returning trades resulting from high pressure
building north of the state. A more typical trade wind pattern
will return for the second half of next week as PW values drop
closer to seasonal levels...while light to moderate trades
continue.

&&

.AVIATION...
The prevailing wind flow will remain light easterly...allowing
widespread land breezes early this morning and sea breezes later today.
Moisture carried by the prevailing wind will affect windward areas
at times. Convection over the islands will develop again later day,
bringing some showers especially during the afternoon and evening
hours. Expect mainly VFR conditions to prevail for all areas this
morning, though passing low clouds may bring MVFR ceiling briefly
along the windward areas.

No AIRMET is in effect early this morning, though AIRMET for mtn
obsc may return again by this afternoon as another round of
convection commences.

&&

.MARINE...
The current long-period south swell is holding around 2 ft at the
local Barbers and Lanai PACIOOS buoys this morning. Peak wave
periods associated with this source, however, are slowly trending
down into the 14 to 15 second band. This source will likely hold
through a good portion of the day today before easing further
through the remainder of the weekend. A small northwest (320
degrees) swell is forecast to fill in later on Sunday, peak on
Monday, then gradually fade Tuesday and Wednesday. As this northerly
source fades, another small southerly swell is forecast to fill in
late Tuesday and Tuesday night and persist through the mid-week
period. For more details regarding the expected surf on Oahu from
these sources, refer to the latest Collaborative Near-shore Swell
and Wind Forecast at www.prh.noaa.gov/hnl/pages/SRF.php#Discussion.

Winds will remain light through the remainder of the weekend due to
a weak trough located northwest of Kauai. This will translate to
light offshore flow through the late night and early morning hours
at the area beaches and nearshore locations, before shifting to
onshore through the late morning and afternoon periods as the sea
breeze develops and pushes ashore. Elsewhere across the marine
areas...light southeast winds will persist into Sunday before
shifting to northeast as a weak boundary pushes east across the
state and high pressure builds north of the marine area. Moderate to
fresh trade winds will return across the state through the upcoming
week...however...they should remain below small craft advisory
levels.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

Discussion...Jelsema
Aviation...Hui
Marine...Gibbs



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