Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 231349
Area Forecast Discussion
National Weather Service Honolulu HI
345 AM HST Mon Jan 23 2017
Winds will gradually subside as a high northeast of the area moves
east and weakens. A ridge north of the islands will maintain
moderate trade winds through mid-week. The trades will focus clouds
and showers over mainly windward areas. Later in the week the ridge
will shift south near the islands as a front approaches from the
northwest and stalls north of the area. The ridge will bring light
winds and dry weather. A band of showers along a new front will move
across the islands next weekend. Trade winds will return early next
week as a new high moves east behind the front.
An east to west band of showery low clouds associated with a
dissipating front is forecast to remain nearly stationary south of
the Big Island. A 1031 mb surface high 925 miles northeast of
Honolulu is forecast to move east at 15 to 20 mph over the next few
days. The high will maintain breezy trade winds over the islands
today. Rainfall will remain light over most areas, but clouds on
the north edge of the frontal band will keep the windward side of
the Big Island rather showery through tomorrow.
As the high moves east, a front about 825 miles northwest of
Honolulu will move southeast toward the islands. Winds over the
islands will steadily subside as the high moves away and the front
approaches. Moderate trade winds will prevail through mid-week. The
trades will carry some showers over windward areas, especially on
the Big Island and Maui, but leeward areas will remain mostly dry.
The front will stall north of the islands and a surface ridge north
of the islands will shift south near the islands on Thursday. Winds
over the area will weaken and daytime sea breezes and nighttime land
breezes will prevail. A ridge aloft will build eastward over the
area and make the atmosphere quite stable, so rainfall will
A new front will move southeast over the islands next weekend,
reaching Kauai Saturday night and moving down to the big Island by
Monday morning. The front is expected to bring widespread showers,
but moisture along the front will likely be too shallow for heavy
rain. A new high will move east behind the front and produce breezy
trade winds early next week.
A strong high northeast of the area is maintaining strong easterly
trade winds across some areas of the Hawaiian waters. Please see the
latest Marine Weather Message, MWWHFO, for further details. The
Small Craft Advisory may need to be extended in some areas overnight.
The strong trade winds and a short-period north swell continue to
produce surf above the High Surf Advisory (HSA) level on east
facing shores of most islands. With the winds and seas shifting out
of the east, surf has dropped below the HSA threshold on Niihau and
Lanai, since the waves there are blocked by Kauai and Maui. The HSA
will likely stay up through this evening along east facing shores of
the other islands.
A large northwest swell will likely produce surf well above the
advisory threshold along north and west facing shores of the smaller
islands from Tuesday through Thursday morning. Another large
northwest swell may produce advisory-level surf along north and west
facing shores of the smaller islands starting Friday night and
continuing into next weekend.
A surface high to the northeast is maintaining strong easterly trade
winds over the main Hawaiian Islands. AIRMET TANGO remains in effect
for moderate turbulence downwind of all of the main Hawaiian Islands.
A band of showery low clouds associated with a dissipating front
remains just southeast of the Big Island. Clouds on the fringe of
this band are moving over the Big Island. AIRMET SIERRA is in effect
for MTN OBSC over east side the Big Island remains in effect. VFR
will prevail elsewhere.
High Surf Advisory until 600 PM Monday for east facing shores of
Kauai, Oahu, Molokai, Maui and the Big Island.
Small Craft Advisory until 600 PM Monday for Maui County Windward
Waters, the Alenuihaha Channel, Big Island Windward Waters and
Big Island Leeward Waters.