textproduct: Honolulu

SYNOPSIS

Mostly dry and stable with a few showers over windward Big Island tonight and Monday. Incoming moisture and an upper low track near or over the area Tuesday to Thursday bringing higher chances of rain. Dry and stable weather returns Friday into next weekend.

DISCUSSION

A weak surface ridge lies northeast of Hawaii with a weak front to the north. Gentle trade winds with localized sea breezes on the leeward sides are the result of the synoptic setup. Low clouds are observed on visible satellite across most leeward slopes from the sea breeze convergence, but only isolated showers are tracked on radar this afternoon. 00Z soundings show a stable atmosphere with inversions around 7-8 kft.

For tonight, leeward clouds will dissipate with most areas remaining mostly clear. Incoming clouds tracking towards the Big Island could bring a few windward showers through the overnight. Gentle to locally moderate trades with isolated windward showers will persist Monday.

By late Monday into early Tuesday, high pressure will strengthen and push the remnant of the front away to the west. Trades will strengthen to moderate to fresh breezes and bring an area of moisture left over from a trough in from the east. An upper low will also dig towards the islands and could enhance the low levels moisture resulting in scattered moderate showers Tuesday through Thursday. Showers will focus windward, but likely some showers will reach leeward sides of the smaller islands.

For Friday into next weekend, moisture and the upper low slide west bringing a drier and more seasonable trade wind pattern.

AVIATION

Clouds and showers have developed over some leeward areas due to sea breeze convergence this afternoon. This is occurring especially on Kauai, Oahu, and Big Island, and should diminish with sunset. Weak trades will strengthen tonight and Monday, and therefore showers should move more toward windward and mauka areas beginning tonight. Expect mainly VFR, but brief MVFR is possible in the stronger showers. No AIRMETs are in effect, and none are anticipated through tonight.

MARINE

No significant changes to the forecast this afternoon.

A weak high pressure ridge north of the islands will strengthen over the next several days. This will bring increasing trade winds to the region and with that, wind driven seas. A low level trough moving in from the east Tuesday through Wednesday will bring an increase in shower activity.

Several overlapping small medium and long period south swells will continue to pass through the region this week, keeping south facing shore surf elevated into next weekend. Surf along remaining shores will remain small due to lack of swell energy, and lighter trade winds. As trades increase later this week, surf along east facing shores will increase.

HFO WATCHES/WARNINGS/ADVISORIES

None.