Hawaiian Weather Synopsis: As we move through this first day of the new work week, we find some changes happening, with more on tap as we push through the week. The most notable thing today is occurring in the marine environment, where rising waves are breaking along our east, south and west shores. The largest of this swell activity is impacting the east shores, with the north shores a little smaller. At the same time we have a late season south swell that was generated about a week ago, down in the southern hemisphere. This will bring a modest rise to our south shores, with the west sides finding the smallest surf. A high surf advisory currently covers the eastern shores…which will continue through Tuesday.
Meanwhile, the trade winds are beginning to break down, although are still at least somewhat active this afternoon. This easing up of the trade winds is being prompted by the influence of a low pressure system to our west-northwest…as shown on this weather map. The forecast calls for these winds to veer around to the east and then all the way around the compass to the southeast. This lighter wind flow from the southeast will shift us into a modified convective weather pattern. This means that skies will dawn quite clear, and slightly cool through probably Wednesday or Thursday. The afternoon hours, especially along the leeward slopes will cloud up quite a bit, thanks to the sea breezes blowing upslope. There may be some showers falling from these clouds, although not many are expected for the time being.
As the trade winds return later Wednesday or Thursday, the bias for showers will shift back over the windward coasts and slopes, generally during the cooler night and early morning hours. The computer models have continued to differ in their outlooks for the second half of the week. At various times during the last week, there has been suggestions of a cold front coming into the state. There’s also been intimations of an upper level low pressure system edging over, or near the state too. There continues to be some questions in this regard, so that the outlook is still being formulated at this time. Perhaps the best bet would be to hold this lightly for the moment, and side with the NWS…who is keeping this low pressure system far enough to the west of the state, which would minimize the lows influence.
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
Our trade winds will be gradually easing up now…taking on a more southeasterly orientation through the first half of this new work week. Glancing at this weather map, it shows high pressure systems far to our northwest, and east-northeast…with low pressure systems to the west and northeast. The trade winds will gradually mellow out over the next several days, becoming southeast. As a new low pressure system develops to our northwest, with its associated cold front approaches Tuesday into Wednesday…these winds will slow down ahead it, then increase again around Thursday into the upcoming weekend .
Lighter winds will be prevail over the next several days…the following numbers represent the strongest gusts (mph), along with directions Monday afternoon:
13 Lihue, Kauai – E
17 Kahuku, Oahu – ENE
17 Molokai – NNE
17 Kahoolawe – SE
27 Kahului, Maui – NE
24 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 Monday afternoon. Looking at this NOAA satellite picture we find stable looking low clouds surrounding the islands offshore…some of which will arrive along our windward sides during the day. We can use this looping satellite image to see a large counterclockwise rotating low pressure system well to our west. There are also lots of thunderstorms far south and southwest of Hawaii, in the deeper tropics. Checking out this looping radar image we see showers over the ocean, with a few impacting our islands locally.
Here are the 24-hour precipitation totals (inches) for each of the islands as of late Monday morning:
2.14 Mount Waialeale, Kauai
0.76 Oahu Forest NWR, Oahu
0.40 West Wailuaiki, Maui
1.10 Kealakekua, Big Island
Here is the latest NWS rainfall forecast
Here are the latest available satellite images:
SURF OUTLOOK: The north shores will find larger northeast swell waves rising Monday into Tuesday. Surf along the south shores will be coming up during the day Monday and Tuesday. The west shores will find modestly rising surf Monday and Tuesday. The east shores will find rising surf into Tuesday…high surf advisory.
North shores – The northeast swell will be reinforced during the day Monday into Tuesday, gradually dropping into Wednesday. A new north-northwest swell will bring the surf up some Thursday into Friday.
West shores – A new late season south swell arrives Monday into Tuesday…tapering off after mid-week. A new north-northwest swell will bring the surf up some Thursday into Friday.
South shores – A new late season south swell will bring the surf up during the day Monday, sticking around into Thursday…then tapering off Friday onwards.
East shores – A new north-northeast swell will bring the surf up again along these beaches during the day Monday, gradually losing size late Tuesday into Wednesday.