Hawaii Weather Synopsis: Expect light to moderate trades to persist through Saturday. Moisture riding in on the trades will bring night and morning showers to windward and mauka sections. Look for light winds to return next week as an approaching front will disrupt the trade wind flow.
No Advisories, Watches, or Warnings are currently in effect.
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Broad Overview of Hawaii’s Weather
Based on the NWS Area Forecast Discussion for Hawaii, issued 20 Oct 2011 at 10:05am HST
The early morning soundings showed that even though boundary layer moisture is not particularly plentiful, the subsidence inversion was near 8500-9000 feet over the main Hawaiian Islands, a little more elevated than usual. This is allowing a decent amount of showers to ride in on the trades. Speaking of the trades, they are hanging on at moderate levels thanks to a subtropical ridge about 700 miles N of Honolulu (see latest weather map). Little change is expected through about Saturday. Upper level troughing west of the islands will keep the trades a little lighter and more easterly than usual.
As the trough sharpens west of the islands this weekend, the background trades will become southeast starting about Sunday. This will gradually bring increasing humidity and most likely vog (volcanic haze) as well to some of the smaller islands by Monday. It also likely means a shift back toward a pattern of afternoon and evening clouds and some showers forced by island heating, with clearing at night. The air mass at that time will not be particularly unstable, so showers should not be too heavy.
The models are still in disagreement about how sharp the mid- to upper-level trough will be and whether or not there will be much in the way of frontal remnants over the main Hawaiian Islands during the middle portion of next week. The latest runs suggest this is less of a possibility, and so it looks like keeping heavy showers out of the forecast is working out fine. NWS will look at the extended forecast in more detail this afternoon.
The following numbers represent the strongest wind gusts (mph), along with directions Thursday morning:
15 Lihue, Kauai – ENE
20 Bellows AFB, Oahu – ENE
22 Molokai – ENE
14 Kahoolawe – E
16 Lipoa, Maui – E
14 Lanai – ENE
24 Upolu Airport – NNE and South Point, Big Island – ENE
Here are the 24-hour precipitation totals (inches) for each of the islands as of early Thursday morning:
0.63 Mt. Waialeale, Kauai
0.18 Waihee Pump, and Manoa Lyon Arboretum, Oahu
0.09 Puu Kukui, Maui
0.62 Kealakekua, Big Island
Here is the latest NWS rainfall forecast
Here are the latest available satellite images:
SURF ZONE FORECAST – OAHU
NATIONAL WEATHER SERVICE HONOLULU HI
900 AM HST THU OCT 20 2011
Surf along north facing shores will be 2 to 4 feet today, lowering to 1 to 3 feet Friday.
Surf along east facing shores will be 1 to 3 feet through Friday.
Surf along south facing shores will be 2 to 4 feet today, lowering to 1 to 3 feet Friday.
Surf along west facing shores will be 3 feet or less through Friday.
Outlook through Wednesday Oct 26: A northwest swell will build this weekend, with surf peaking near the advisory level of 15 feet along north facing shores Sunday and Monday, and then slowly lowering thereafter.