Hawaiian Weather Synopsis: The forecast out through the next week looks to be pretty well settled on, although the second cold front of this period, arriving around next Tuesday or Wednesday…may still need a bit of fine tuning over the next several days. While we’re noting cold fronts, the first of these two will be on our doorstep at some point between Friday evening into Saturday morning. These two early season frontal passages will have the most important bearing on our local weather conditions here in the islands during the next seven days.
In terms of precipitation, both of these cloud bands will likely bring some moisture with them, depending upon how well they hold together, as they push into the tropics. Besides the intensities of these showers, it will depend upon whether either of them begins to fall apart as it grades into our island area. As is often the case, perhaps Kauai and Oahu would have the greatest chance of seeing rainfall. It of course depends upon exactly which direction the fronts get carried our way, from the northwest, north or northeast. Since we haven’t had much moisture falling lately, it would be good to see all the islands get a little precipitation.
As far as winds go, they will be going through their changes, in both the approach and departure of these fronts. For the time being the trade winds will slow down some now, as the first front weakens our trade wind producing high pressure ridge. Then, as the first front goes through, we’ll see a slightly cool surge of trade wind in its wake. These northeast breezes won’t last long however, as the second front approaches…they will swing around to the east or even south. Then, we’ll likely see another surge of trade winds by the middle of next week, right behind the front with its rainfall.
PDC Hazards Atlas showing the Hawaiian Islands in the north central Pacific along with the 3 hour accumulation of precipitation
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 remain locally breezy today although becoming gradually lighter through Friday morning. Glancing at this weather map, it shows a strong 1037 millibar high pressure system far to our north-northwest, with two weaker 1021 millibar high pressure cells to our northeast. There’s an elongated cold front coming off the mainland west coast, which runs southwest and west to near the International Dateline. We’ll be in a slightly lighter wind flow through Friday morning. This will occur due to the cold front pushing our trade wind producing ridge down closer to the Aloha state. The trade winds will increase again temporarily later in the day Friday and Saturday, pushing the cold front down into the state then. A slightly cooler air mass will over-ride the state in the wake of this frontal passage…through Saturday night. As a second cold front approaches from the north and northeast…will grade right back into a lighter southerly breezes ahead of that second cold front around later Tuesday or Wednesday of next week.
Trade winds continue…the following numbers represent the strongest gusts (mph), along with directions Wednesday afternoon:
20 Port Allen, Kauai – ESE
17 Kahuku, Oahu – E
14 Molokai – NE
25 Kahoolawe – ESE
18 Lipoa, Maui – NE
07 Lanai – WSW
28 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 Wednesday afternoon. Looking at this NOAA satellite picture we find just a few low clouds generally offshore of the islands…although they are being carried over the windward sides of the islands in a few places. We can use this looping satellite image to see those low clouds moving along in the trade wind flow. There’s a new area of high level clouds located offshore, to the west of the islands….heading our way. Checking out this looping radar image we see just a few showers over the ocean, with not many impacting the windward sides.
Here are the 24-hour precipitation totals (inches) for each of the islands as of late Wednesday morning:
0.08 Hanalei River, Kauai
0.35 Kaneohe MCBH, Oahu
0.15 Molokai
0.00 Lanai
0.00 Kahoolawe
0.36 West Wailuaiki, Maui
0.41 Kapapala Ranch, 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 find a lowering northwest swell Wednesday and Thursday. Surf along the south shores will flat to very small through Thursday. The west shores will find generally smaller surf both days. The wind swell along the east facing shores will remain small to very small through Thursday.
North shores – The northwest swell will drop a bit Wednesday into Thursday. A new northwest swell will arrive Friday, bringing the surf back up into the weekend.
West shores – The northwest swells will keep coming, keeping these beaches breaking, although dropping some into Thursday. A new northwest swell will arrive Friday, with waves continuing into the weekend.
South shores – The recent late season south swell activity will be nearly gone now, becoming very small to flat through Friday. There’s an outside chance of a modest bump again this weekend.
East shores – As the trade winds become somewhat lighter for the next few days, the wind swell waves will drop a little in turn. A northeast swell this weekend will bring the surf up along these beaches.