textproduct: Honolulu

SYNOPSIS

A ridge of high pressure will remain anchored in place north of the Hawaiian Islands for the foreseeable future. Easterly trade winds will continue to blow across the region through the end of this week. Shower activity will show increasing trends on Tuesday, and a stronger increase from Thursday into the weekend as deeper tropical moisture associated with a weak easterly wave moves from east to west across the state. Showers will favor windward mountain slopes of each island during the overnight to early morning hours.

DISCUSSION

High pressure will remain in place north of the state into the weekend. This will keep moderate to locally breezy east- northeasterly trade winds blowing across the region. Brief periods of rain showers will move in on the trades, primarily focusing over windward and mountain areas during the overnight and early morning hours through Thursday.

A more noticeable change arrives Thursday night and lasts into the weekend as deeper moisture in association with the remnants of former Tropical Storm Douglas brings more humid conditions and more widespread shower activity. Instability indices also show marginal potential for some isolated thunderstorm development over the Big Island interior on Friday afternoon when some of the deepest moisture is forecast to move through. Expect muggier conditions on Friday and into the weekend as dew points rise into the lower 70s for most locations. Periods of showers look to continue into early next week.

AVIATION

Moderate to locally breezy trades will continue through the period. Low clouds and scattered showers will continue to impact windward and mountain areas, with some spillover into leeward sites. VFR conditions are broadly expected, with localized MVFR mainly for windward/mauka sites.

AIRMET Tango remains in effect for moderate low level turbulence over and downwind of terrain for all islands. This AIRMET will likely continue through the next several days.

MARINE

A strong high pressure ridge centered north of the state will help to drive fresh to strong trades across the local waters through Tuesday, then ease slightly to fresh to locally strong for midweek and beyond. The Small Craft Advisory, currently in effect for all local waters, has been extended through Tuesday afternoon.

A moderate, long period, south southwest (190-200 degree) swell will continue to help boost surf along south facing shores to above seasonal averages today, but just shy of Advisory levels. This swell should gradually lose energy from Tuesday through the remainder of the week. Expect small surf for south facing shores leading into this weekend with mainly background energy.

Surf along east facing shores will remain choppy through the week as fresh to locally strong trades hold. Expect flat to tiny surf along north facing shores through the forecast period.

HFO WATCHES/WARNINGS/ADVISORIES

Small Craft Advisory until 6 PM HST Tuesday for all Hawaiian waters-