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Nov
21
2011

Hawaii Weather Overview


Hawaiian Weather Synopsis: 
The long lasting high and middle level clouds of late have finally moved far enough east, that sunshine is actually present over most of the state…at least at the time of this writing. The Big Island was still covered up with rather thick high cirrus clouds, as shown by this satellite image. We could see a general clearing of this high stuff over the next couple of days, although the models are suggesting that they could make a reappearance beginning Thanksgiving Day. Meanwhile, lower level clouds continue to carry passing showers. These are riding in on the strong and gusty trade winds, at least at times. Thus, the windward sides are picking up the most generous precipitation totals. The leeward sides will see a few rain drops flying over there too, although on the smaller islands…rather than on the Big Island or Maui.

The trade winds are gusting up to 40 mph today, which makes them strong and gusty. The NWS is keeping the small craft wind advisories active over most of the state, although its not a total coverage. These autumn trades are going to be with us through the rest of this week, right on into early next week at least. They will remain blustery through mid-week, then relax a touch Thursday and Friday, before surging again this weekend. This surge in trade wind speeds will be thanks to both a strengthening high pressure system to our north then, and a cold front that will push through the state…with this surge in wind speeds following closely in its wake. The frontal passage will bring showers, although the following winds will quickly turn very dry. This suggests that those breezes may feel a little cool for a day or so…in a tropical sense that is.

Just a quick note about a very late season hurricane that’s churning the waters of the far eastern Pacific today. It’s name is Kenneth, and he spun up this past weekend.  It’s getting very close to the end of the 2011 hurricane season, so that it’s unusual to find not only a hurricane spinning in the eastern Pacific…but also one that may attain the major hurricane designation over the next day or so. Since 1949, there have been just three eastern Pacific named storms that formed after November 18. If in fact Kenneth were to reach the major hurricane status, it would be the latest such occurrence in the eastern Pacific since the beginning of the satellite era! The good thing about the location of this strengthening hurricane, is that it’s staying away from the Mexican coast, and isn’t likely to impact any land areas through the remainder of its life cycle. Here’s a looping satellite image of this hurricane. By the way, this is just information, rather than any warning (whatsoever) for our Hawaiian Islands.

PDC Global Hazards Atlas centered on the central Pacific Ocean near Hawaii is displaying precipitation accumulation over the last three hours

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

Broad Overview of Hawaii’s Weather

As this weather map shows, we find a 1025 millibar high pressure system located to the east-northeast of the Hawaiian Islands, with a second 1028 millibar high pressure cell far to our northwest Monday afternoon.  At the same time, there’s a trough of low pressure parked out to the west of Hawaii.  Our trade winds remain strong and gusty, and will remain so for the next couple of days. The computer models continue to suggest that our local trades will decrease on Thanksgiving into Friday. They go on to say that our strong and gusty trade winds will ride in behind a cold front this coming weekend…into early next week.

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

30                 Lihue, Kauai – NE
35                 Kahuku Training Area, Oahu – NE
32                 Molokai – NNE
39                 Kahoolawe – E
30                 Kahului, Maui – NE
27                 Lanai
33                 South 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 Monday afternoon. Looking at this NOAA satellite picture we find that the long lasting high and middle level cloudiness is still over the Big Island, but has cleared the rest of the state…finally. We can use this looping satellite image to see low clouds, at least that can be viewed through the upper level clouds, are being carried westward in the gusty trade wind flow. Checking out this looping radar image we see  showers falling locally over the ocean, most of which are light to moderately heavy. Most of this precipitation remains offshore, although some is falling as showers over the islands in places too.

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

2.32               Mount Waialeale, Kauai
1.25               Moanalua, Oahu
0.19               Molokai
0.00               Lanai
0.00               Kahoolawe
0.66               Kaupo Gap, Maui
1.48               Glenwood, 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:    Rough surf east shores as the trade wind speeds remain active. The north shores will increase a bit more Monday, remaining active Tuesday. The west sides will get a bit larger, and south shores will be very small to flat through Tuesday.   

North shores –  A short lived northwest will arrive Monday…gradually lowering into mid-week. A larger northwest swell will arrive during the second half of the week, lasting into the weekend.

West shores –    A minor bump from the new northwest swell locally Monday…lasting a few days. These beaches will find larger waves arriving later in the new week, as a new larger NW swell arrives into the weekend.

South shores –    Small to very small surf…locally flat through the new week

East shores –    Surf remaining rough and active, as the trade winds continue into the new week. Conditions will be rough and choppy due the gusty trade wind flow.

NOAA animated wave model