Expires:No;;378495
FXHW60 PHFO 260157
AFDHFO

Area Forecast Discussion
National Weather Service Honolulu HI
357 PM HST Thu Apr 25 2024

.SYNOPSIS...
Strong trade winds will gradual decrease and veer toward the
east-southeast through early next week. Several plumes of moisture
will produce passing showers across windward and mountain areas
through Saturday. A drier weather pattern is expected Sunday into
early next week with light to moderate easterly trade winds. Trade
winds should be light enough for sea breezes to develop during the
day.

&&

.DISCUSSION...
A 1031mb high far north of the state is currently producing strong
trade winds across the state this afternoon. Latest satellite and
radar imagery shows mostly dry conditions across the state with
some scattered showers over windward areas and the Kona slopes of
the Big Island. Looking upstream of the state, there is a plume of
moisture upstream of Maui, which will likely bring an increase of
scattered showers tonight across windward areas. Another plume of
moisture looks to arrive sometime late Friday into Saturday.
Overall an increase of showers is expected through Saturday,
primarily over windward areas. Rainfall amounts should remain
light to moderate, due to stable conditions aloft.

A developing trough northwest of the state over the next few days 
will cause the winds to veer toward the east-southeast on 
Saturday, which should decrease the winds across leeward areas of
the smaller islands due to shadowing from the Big Island. A 
hybrid wind pattern is expected over the weekend over leeward 
areas of the smaller islands with a mix of easterly trade winds 
and sea breezes. Meanwhile for the windward areas, moderate to 
locally breezy trade winds are expected this weekend. As the 
trough moves closer to the state early next week, winds will 
weaken further and sea breezes will develop across more areas. Sea
breezes during the day time should lead to afternoon clouds each
afternoon over interior and leeward areas. Due to precipitable
water values being near normal or just below normal, no
significant precipitation is expected with the afternoon showers
but some light rain will be possible. 


&&

.AVIATION...
Breezy to locally windy trade winds will continue through Friday.
Clouds and showers will favor windward and mauka areas, with 
isolated showers occasionally spilling over to leeward 
areas...bringing periodic MVFR conditions. Cloud cover and shower
activity will be greatest overnight into the morning hours. 
Otherwise, VFR conditions will generally prevail.

AIRMET Tango is in effect for moderate low-level turb downwind of
the terrain for all islands. These conditions are expected to 
improve sometime tonight heading into Friday.

&&

.MARINE...
A 1031 mb surface high, centered around 900 nm northeast of the 
state, will slowly drift eastward over the next several days. This
feature will continue to help drive strong to locally near gale 
east northeasterly trade winds across the islands this afternoon 
through tonight. Friday into the weekend, low pressure is 
forecast to develop well northwest of Hawaii. In response, 
easterly winds will gradually weaken to light to moderate and 
shift slightly out of the east southeast. A Small Craft Advisory 
(SCA) continues for all Hawaiian coastal waters through Friday 
morning and has been extended for windward Oahu waters and 
eastward through Friday afternoon. The advisory may need to be 
extend into Saturday for some of the more typical windier 
locations around the Big Island and Maui County. 

Surf heights will remain below advisory thresholds for all shores
through the forecast period. Hanalei buoy (51208) shows a medium 
period northwest swell continuing to fill in. Expect surf to rise
locally through the evening and peak tonight. Another small, 
medium period northwest pulse will enter the waters Friday night, 
peak Saturday, and subside Sunday. Expect these swells to produce 
small surf along north and northwest facing shores. Persistent 
trades will continue to produce choppy, rough surf through Friday 
along east facing beaches. By this weekend, weakening trades will
allow this surf to lower and hold into early next week. Small 
background southerly swell, observed this afternoon at Barbers 
Point Buoy (51212) as 2 feet 14 seconds, will lead to small surf 
along south facing beaches through the forecast period.


&&

.HFO WATCHES/WARNINGS/ADVISORIES...
Small Craft Advisory until 6 AM HST Friday for Kauai Northwest 
Waters-Kauai Windward Waters-Kauai Leeward Waters-Kauai Channel-
Oahu Leeward Waters.

Small Craft Advisory until 6 PM HST Friday for Oahu Windward 
Waters-Kaiwi Channel-Maui County Windward Waters-Maui County 
Leeward Waters-Maalaea Bay-Pailolo Channel-Alenuihaha Channel-
Big Island Windward Waters-Big Island Leeward Waters-Big Island 
Southeast Waters.


&&

$$


DISCUSSION...Kino
AVIATION...Farris
MARINE...Thomas/Vaughan