Area Forecast Discussion
Issued by NWS Honolulu, HI
FXHW60 PHFO 060623
Area Forecast Discussion
National Weather Service Honolulu HI
823 PM HST Mon Dec 5 2016
An mid level trough near Kauai will be replaced by a deeper upper
level trough moving in from the west, which sill keep the
atmosphere over the islands unstable through the coming weekend.
A weak ridge will persist north of the area through Thursday and
produce gentle trade winds. The trades will be light enough to
allow afternoon sea breezes to develop and produce clouds and
showers over interior areas. Nighttime land breezes will produce
partial clearing at night. The upper level trough may deepen
during the second half of the week and bring an increase in clouds
No changes to the forecast package are expected this evening. The
mid level trough currently near the islands is expected to slowly
lift the north over the next couple of days. Meanwhile, and upper
level trough near the dateline will move to the east and will help
to maintain an unstable airmass over the islands into the upcoming
A weak surface ridge north of the islands will maintain a light
background trade wind flow for the next several days. The winds
will likely remain light enough for daytime sea breezes and
overnight land breezes to set up in many locations. As such,
expect at least partial clearing overnight, with cloud build ups
during the afternoon. As the new upper level trough moves closer during
the second half of the week, we could see an increase in shower
The models have similar temperatures at 700 mb over the next
couple of days, while the GFS is a touch colder at 500 mb than the
ECMWF. Meanwhile precipitable water values near the Big Island
remain at or slightly above normal through much of the week, with
slightly drier conditions over the smaller islands. Earlier runs
had indicated a more unstable airmass moving over the islands, but
the latest runs suggest that while colder temperatures could move
in aloft, they won`t coincide with the moisture.
Occasional MVFR conditions will affect the Big Island, Oahu and
Kauai this evening, and possibly through the late night into
Tuesday morning. Otherwise, expect VFR conditions to prevail.
AIRMET Sierra for mountain obscuration is posted through this
evening for the Big Island, Oahu and Kauai. Conditions are
forecast to improve late tonight, but there is a chance that this
AIRMET may need to be extended for some areas through Tuesday
AIRMET Zulu is in effect for light to moderate icing within thick
mid level cloudiness over and around the Big Island. These
conditions may linger over the Big Island overnight into Tuesday.
AIRMET Tango is in effect for moderate turbulence between 150 and
FL350 from Maui southeastward. These conditions are expected to
improve late tonight.
Winds and seas are expected to remain below small craft advisory
thresholds over the next several days. A series of northwest
swells will continue, but surf will remain well below the High
Surf Advisory threshold.
Wind Advisory until 6 AM HST Tuesday for Big Island Summits.