Pacific Disaster Center Fostering Disaster Resilient Communities  

Providing Weather and Hazard Related News

Weather Wall

 

 

Dec
13
2011

Hawaii Weather Overview

   Locally breezy, off and on showery, heavy flooding rainfall on some of the islands

PDC Global Hazards Atlas displaying cloud cover and 3 hour precipitation accumulation...over and around the Hawaiian Islands

Hawaiian Weather Synopsis:  The off and on wet weather continues here in the islands, with localized flooding on several of the islands. The largest precipitation amounts have reached up over 7.00″ on at least two our islands in the chain during the last 24 hours. The area from Oahu down through Maui County to the Big Island continue to have a flash flood watch in effect at the time of this writing. An unstable atmosphere, along with abundant low level moisture is leading to this inclement weather pattern. The thick high and middle level clouds are adding to this Seattle-like reality, which has been shifting around at times, although is currently over just parts of Maui County and the Big Island…as seen on this satellite image.

The computer models continue to suggest that we’ll dig ourselves out from under this overcast cloud layer(s) pretty soon. Already Kauai and Oahu are seeing clearing skies, at least the high stuff, while there are small blue patches starting to appear over Lanai and Molokai in places. Wednesday should continue this gradually improving weather, especially along our leeward sides. As our easterly trade winds fill back into the area, the windward sides will continue to find passing showers at times into Friday. Then, as we push into the upcoming weekend, the trade winds are expected to increase in strength, becoming rather strong and gusty again. This wind flow will continue to bring more showers to our already soggy windward coasts and slopes.

Click on the following link for the latest National Weather Service advisories and warnings:   Wind/Surf/Flood related advisories or warnings

Details of Hawaii’s Weather – Wind/Precipitation/Surf

As this weather map shows, we find a 1027 millibar high pressure system located to the northeast of the Hawaiian Islands Tuesday afternoon.  This high pressure cell has an elongated ridge that runs from the center west-southwest across the International Dateline…into the western Pacific. This ridge is positioned to the north of the state, which will keep our winds blowing, although will be subdued to some extend by a trough of low pressure draped over the state now. Easter to east-southeast winds will return, gradually becoming more easterly trade winds through Friday…then strengthening from the trade wind direction this weekend into early next week.

The following numbers represent the strongest wind gusts (mph), along with directions Tuesday afternoon:

18                 Port Allen, Kauai – NE
20                 Kahuku, Oahu – NE
09                 Molokai – NE
00                 Kahoolawe
17                 Lipoa, Maui – SE
13                 Lanai – NE
18                 Upolu Point, Big Island – NE

We can use the following links to see what’s going on in our area of the north central Pacific Ocean early Tuesday afternoon. Looking at this NOAA satellite picture we find that high and middle level cloudiness stretches across Maui County and the Big Island, leaving Oahu and Kauai under just lower level clouds. We can use this looping satellite image to see this high level moisture streaming up from the southwest, over the eastern islands…although it appears to be shifting eastward. This cloudiness masks the lower level showers that are being carried our way on the lower level wind flow.   Checking out this looping radar image we see showers over the ocean, most of which are in the light to moderately heavy category, although some are locally heavier, the most active  areas are coming into the  windward sides of the central islands.

Here are the 24-hour precipitation totals (inches) for each of the islands as of late Tuesday morning:

4.15               Mount Waialeale, Kauai
7.08               Moanalua RG, Oahu
1.63               Molokai
0.00               Lanai
0.02               Kahoolawe
1.19               Puu Kukui, Maui
0.12               Kawainui Stream, Big Island

Here is the latest NWS rainfall forecast

Here are the latest available satellite images:

Hawaii Infrared satellite image
Animated Satellite image of Hawaii region
Latest satellite image – Close-in visible satellite view
Latest radar image – Looping

SURF OUTLOOK:   The north shores will be small Tuesday and Wednesday. The west sides will be very small Tuesday and Wednesday. Surf along the east shores will remain active, rough and choppy through Wednesday…then gradually smooth out and lower in size. South shores will be very small to locally flat.

North shores –   The most recent large northwest swell will gradually lower through mid-week. The next northwest swell, although quite a bit smaller than the one that’s been active lately, will arrive Thursday…lasting for a few days along these beaches. A second NW swell will arrive Friday, keeping the surf up into the weekend.

West shores –   The northwest swell will keep these beaches breaking, although much smaller now than over the weekend and late last week.  The next batch of waves, although considerably smaller than the the most recent NW swell was, will arrive Thursday, with a second northwest swell approaching on Friday into the weekend.

South shores –   Surf will remain very small to flat on these leeward shores.

East shores –    Surf will  gradually lower  in size, coming up again this weekend, and taking on a rough and choppy nature…along with the strengthening trade winds.

NOAA animated wave model