textproduct: Honolulu

SYNOPSIS

Moderate trades will gradually build breezy levels tonight through Thursday as weak troughing around the state dissipates and a new surface high develops north of the state. Expect limited clouds and showers to focus along windward and mauka areas, particularly overnight and early morning hours. Slightly wetter tradewind showers will be possible late Friday into the weekend. A drier tradewind pattern may develop early next week.

DISCUSSION

Limited clouds and showers can be seen mainly along windward and mauka areas, except for the Big Island where light to moderate showers are developing along the kona slopes. Starting tonight, upper level trough will have moved east of the state, while mid level ridging continues to limit clouds and showers to windward and mauka locations, especially overnight and early morning Wednesday. Rainfall totals are expected to be less than what was observed overnight Monday into Tuesday morning.

A surface high will develop and shift northwest of the state Wednesday allowing tradewinds to gradually strengthen to more typically breezy levels throughout the day and Thursday as the high settles north of the state. During the this time mid and upper level ridging will maintain dry and stable tradewind pattern while passing bands of low level clouds and showers embedded within the tradewind flow focuses light showers along windward and mauka areas.

An upper level trough will approach the state Friday just as an area of enhanced low level moisture moves from east to west across the state Friday afternoon into Saturday, increasing chances of showers for windward and mauka slopes. Cooling temperatures in the mid levels could make for some brief isolated heavy showers. Although there will be some lingering instability over the state for the rest of the weekend, there could be an over all drying trend as low level moisture becomes limited into early next week.

AVIATION

Moderate trades will persist through Wednesday with mostly VFR conditions expected across the state. Brief MVFR ceilings will be possible with any passing shower, but overall mostly dry conditions are expected through Wednesday afternoon.

No AIRMET's are in effect.

MARINE

Troughs to the west and east, coupled with the high to the far northeast with an accompanying ridge north of the islands will maintain gentle to moderate trade winds through tomorrow. As the troughs weaken, the pressure gradient will tighten, and trades will strengthen to moderate to locally fresh Thursday. Winds may strengthen to Small Craft Advisory (SCA) levels as early as Wednesday night in some of the typical windier waters near Maui and the Big Island. Winds are then expected to remain at SCA levels through the weekend.

The current long period northwest swell will linger into tomorrow, holding surf near seasonal average for north and west facing shores, before declining Wednesday night through Friday. By late Friday, a medium period north- northwest swell will build and once again help bring surf to near seasonal averages through the weekend.

The current long period south-southwest swell will keep surf along south facing shores elevated through tomorrow. Another long period south swell will help produce surf near seasonal average Thursday into early this weekend.

Surf along east facing shores will remain small through Thursday as small wind waves and tiny east swell persist. Choppy surf will increase slightly as trade winds strengthen across the region Friday into the weekend.

FIRE WEATHER

Moderate trade winds will gradually strengthen to typical breezy levels by Thursday. Dry air will keep RH levels near- critical values each afternoon for parts of the state for the next several days. RH values will increase towards the end of the week before another drying trends begins over the weekend into early next week. Inversion heights tonight will range from 5,000 to 6,000 ft.

HFO WATCHES/WARNINGS/ADVISORIES

None.