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000
FXHW60 PHFO 150317
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
517 PM HST Sun Apr 14 2024

.UPDATE...
The front has moved through Kauai and the threat of heavy rain has
ended. Thus, the Flood Watch has been cancelled. A Flood Watch
remains in effect for Oahu and Maui County through Monday. The
front is expected to push through Oahu late tonight and through
Maui County late Monday.


&&

.SYNOPSIS...
The cold front is starting to move down the island chain and is
producing a band of moderate to locally heavy rain ahead of the
front with improving weather conditions and westerly winds behind
the front. The frontal boundary should be northeast of the Big
Island by Tuesday. Expect a more typical trade wind pattern to
return with showers favoring windward and mauka locations through
the second half of the week.

&&

.PREV DISCUSSION...
The frontal boundary has pushed through Kauai and is now
approaching Oahu this afternoon. Latest radar and satellite
imagery shows the band of moderate rain over Oahu at the moment
where we could expect anywhere from 1 to 3 inches of rain with
isolate pockets of higher amounts. The Flood Watch remains in
place over the smaller islands, but the Flood Watch for Kauai will
likely be cancelled soon. The moderate to locally heavy band of
rain should be moving into Maui County late tonight into Monday
with improving weather conditions expected over Oahu by Monday
morning. Due to the lack of instability, rainfall rates will
continue to be in the one inch per hour rates with pockets of 2
inch per hour rates. With the lower rainfall rates the main
flooding concern will be over urban and poor drainage areas where
steady moderate to locally heavy rain may cause issues. For the
most part, we are expecting mainly ponding of water on roadways
with the outside chance of flash flooding.

Currently on the Big Island, we do have a High Wind Warning
for the summits due to a strong subtropical jet nosing into our
area. A Wind Advisory is also in effect for Haleakala on Maui
through Monday afternoon. Over on the Big Island this afternoon,
we did see a few light showers develop along the slopes with
mainly rain at the summits. The snow levels remain high this
afternoon, but it should drop some this evening which could allow
for snow and icy conditions. Due to the potential for slick road
conditions, a Winter Weather Advisory is in effect for the summits
of the Big Island through tonight.

As the frontal boundary continues to weaken and approaches the Big
Island, we should see an increase of showers on Monday into Monday
night. But overall rainfall amounts should remain light to
moderate.

By Tuesday, the frontal boundary should be northeast of the Big
Island, with northwest to north winds expected behind the front.
Shallow cumulus clouds behind the front could produce some light
showers. By Wednesday afternoon, a ridge of high pressure will be
building north of the state and our typical northeast trade winds
should return. Some moisture is expected to ride in with the trade
winds during the second half of the week and we should expected
scattered showers across windward areas and isolated showers over
leeward areas.


&&

.AVIATION...
Showers are moving out of Kauai where improving conditions and
veering winds to westerly can now be expected. The shower band is
now moving over Oahu and will bring MVFR with isolated IFR
possible, also to be followed by improving conditions and veering
winds. The progress of the frontal boundary will slow this evening
and the front will stall and weaken over the eastern end of the
state tonight into Monday.

AIRMET Sierra for IFR remains in effect for Kauai, though it will
likely be transitioned to mountain obscuration later this
afternoon. AIRMET Sierra for mountain obscuration remains in
effect for Oahu and may eventually be needed for portions of Maui
County.

AIRMET Tango for turbulence downstream of mountain ranges remains
in effect for Kauai and Oahu. AIRMET Tango may also be needed for
tempo moderate upper turb FL280-FL450 by midday.


&&

.MARINE...
A front near Oahu this afternoon will slowly push eastward today
through Monday, before stalling out and slowly dissipating near
the Big Island. A Small Craft Advisory is posted for the
Alenuihaha Channel and leeward Big Island waters for Monday as
frontal winds funnel trough the terrain. Light to moderate west
to northwest winds will fill in behind the front. Winds will
become rather light by Monday night and continue through
Wednesday, with moderate trades potentially returning for the
latter part of the week.

Surf along north and west facing shores will trend up tonight and
Monday as a northwest swell arrives. Surf may reach low end
advisory levels along north facing shores of the smaller islands
late in the day Monday and Tuesday before fading Tuesday night.
Surf along east facing shores will continue to slowly decline
through Monday, with only small very small surf expected through
the remainder of the upcoming work week. Small, medium to long
period south swell will keep some small surf rolling into south
facing shores through late in the week.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Monday afternoon for Waianae Coast-Oahu
North Shore-Olomana-Central Oahu-Waianae Mountains-Lanai Mauka-
Kahoolawe-Maui Windward West-Maui Leeward West-Haleakala Summit-
East Honolulu-Honolulu Metro-Ewa Plain-Koolau Windward-Koolau
Leeward-Molokai-Lanai Windward-Lanai Leeward-Lanai South-Maui
Central Valley North-Maui Central Valley South-Windward
Haleakala-Kipahulu-South Maui/Upcountry-South Haleakala.

Wind Advisory until 6 PM HST Monday for Haleakala Summit.

High Wind Warning until 6 PM HST Monday for Big Island Summits.

Winter Weather Advisory until 6 AM HST Monday for Big Island
Summits.

Small Craft Advisory from 6 AM to 6 PM HST Monday for Alenuihaha
Channel-Big Island Leeward Waters.


&&

$$


UPDATE...Kino
DISCUSSION...Kino
AVIATION...JVC
MARINE...Foster