Issued: Nov 07, 2009 10:00 AM HST
Synopsis
High pressure to the north will bring moderate trade winds to the islands into next week. Trade showers will favor windward and mauka sections, but some will be blown over to leeward areas.
Discussion
Pressure falls of 1 to 2 millibars over the last 24 hours indicate that the surface high to the north has weakened slightly, which explains the slightly lighter trade winds we are seeing around the islands. Progs say that the high should maintain the trades at about the present velocities at least through the first half of next week.
Models also predict that an upper level low will linger west northwest of Kauai, with southwesterly flow aloft carrying patchy high clouds up over the state from time to time. The low is forecast to weaken into an upper level trough that will approach Kauai Sunday night. The trough will bring some unstable air to the islands, which may increase the shower activity.
Heading into the middle of the week, models show a stronger upper level trough moving over the islands from the north. An upper level low may develop in the trough over the islands Wednesday afternoon and night. The upper low and trough may result in wet trade winds which is reflected in the wet forecast from Wednesday onward.
Marine
The small craft advisories have been adjusted to better reflect the expected wind speeds and combined seas. The advisories are now in effect for only the windier areas around Maui and the Big Island. In spite of the north northwest swell, surf will remain below advisory levels through Wednesday.
Watches/Warnings/Advisories
Small craft advisory until 6 pm HST Sunday for maalaea bay-pailolo channel-alenuihaha channel-big island southeast waters.