Breezy trades will gradually weaken to light to moderate speeds by the latter half of the week. A band of moisture focused over the western end of the state will bring increased shower coverage across the islands of Kauai and Oahu through Monday. Otherwise, periodic showers will filter in on the trade wind flow, mainly focusing over windward and mauka areas. By next weekend, the background flow may become light enough to support land and sea breeze development.
A high pressure ridge north of the islands will maintain moderate to breezy trade winds for the next couple of days. Clouds and showers being carried in on the trades will bring periods of MVFR conditions primarily to windward and mountain areas, but winds will be strong enough to carry some showers to leeward areas. Otherwise, VFR conditions are expected to prevail.
AIRMET Sierra is in effect for mountain obscuration for windward and mountain areas of Kauai and Oahu due to ongoing and upstream showers. These conditions are expected to be intermittent throughout today, but some clearing is possible this afternoon.
AIRMET Tango is in effect for mechanical turbulence to the lee of the mountains, and that is expected to continue over the next couple of days with little change in the trade wind speeds expected.
Surface high pressure will remain anchored far northeast of the islands through early this week. A Small Craft Advisory (SCA), remains in effect for the typical windy waters around Maui and the Big Island. By the middle of this week, a ridge north of the islands associated with the high will be weakened and depressed southward. As a result, trades will drop further and allow the SCA to be cancelled entirely Tuesday or Wednesday.
Small long-period forerunners of the next south swell are starting to show up this morning along our near shore buoys with energy centered in the 18 to 22 second bands. Energy from this swell is expected to peak late Monday into Tuesday and bump up surf to slightly higher than the June average, but still below advisory criteria. Expect this swell to fade through midweek. A smaller pulse of south-southwest swell is due late Thursday and Friday, and a more significant south-southwest swell is on track to arrive next weekend, likely bringing advisory level surf by late Sunday along south facing shores.
Small background energy from the west-northwest is possible over the next several days from a former Typhoon in the West Pacific last week. Rough surf along east-facing shores will remain around seasonal average today, then slowly decline through the midweek as trade winds ease.
Small Craft Advisory until 6 PM HST Monday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
