RSS Feeds
Issued: Jan 16, 2013 8:30 PM HST
Synopsis
A cool and dry air mass remains across the area with light northerly winds through at least Thursday. Light showers will continue to favor windward slopes. A lingering band of moisture will maintain higher chances of rain over the Big Island. A weakening front is expected to reach the main Hawaiian islands by Friday and bring stronger northeast winds through the weekend.
Discussion
Expect the cool and dry weather to continue during the next couple of days. Generally light N winds will prevail across the smaller islands with morning lows still reaching the upper 50s to lower 60s near the coast. Limited night showers may affect northern windward slopes, while leeward areas should remain dry for the most part.
The remnants of a frontal boundary are keeping a band of moisture near the Big Island and providing higher chances of showers. However, rainfall in general will remain light. Daytime heating may help in generating some afternoon convection over the Big Island slopes, and to a lesser extent over the smaller islands.
Stronger NE winds should develop during the weekend as a weakening fropa affects the island chain. Better chances for rain will still reside over windward areas. Pressure gradients will become tighter and produce gusty ne/n winds across the state. Then a cooler and drier air mass settles into the area in the wake of the fropa, but temperatures are not expected to be as cold as in the last couple of nights.
For early next week, a return to a more typical trade wind weather regime is anticipated as high pressure strengthens to the N of the aloha state.
Marine
A high surf advisory for north facing shores is in effect across the smaller islands, and including west facing shores of Kauai. Borderline conditions will persist into Thursday afternoon.
The high surf advisory will likely be upgraded to a warning for late Thu night as a much larger, very long period swell will reach the area. Low, long period forerunners around 25 seconds will arrive on Thu, and the swell will build to warning levels by late Thu night or early Fri morning. Elevated, warning level surf along N and W facing shores will continue through the weekend as the low passing NE of the islands delivers reinforcing n/nw swells. A small craft advisory for seas of 10 ft or more will be needed as early as Thu night and will persist through at least Sun.
Aviation
Light north flow is expected across the area tonight. A dissipating front moving slowly over the island will produce isol -shra, but VFR conditions are expected to persist.
Watches/Warnings/Advisories
High surf advisory until 6 pm HST Thursday for north and west facing shores of Niihau and Kauai, and the north facing shores of Oahu, Molokai, and Maui.
Wind advisory in effect until 6 am HST Thursday for the Big Island summits.
DISCUSSION AND MARINE...REYNES
AVIATION...M BALLARD