Hawaiian Islands Weather Details & Aloha Paragraphs / April 11-12, 2018

Air Temperatures – The following high temperatures (F) were recorded across the state of Hawaii Wednesday…along with the low temperatures Wednesday:

77 – 70  Lihue, Kauai
84 – 73  Honolulu, Oahu
80 – 70  Molokai AP
82 – 71  Kahului AP, Maui
82 – 74  Kailua Kona
77 – 72  Hilo AP, Hawaii

Here are the latest 24-hour precipitation totals (inches) for each of the islands Wednesday evening:

2.40  Mount Waialeale, Kauai
1.89  Manoa Lyon Arboretum, Oahu
1.09  Molokai
0.00  Lanai
0.01  Kahoolawe
6.05  West Wailuaiki, Maui
7.07  Saddle Quarry, Big Island

The following numbers represent the strongest wind gusts (mph) Wednesday evening:

31  Port Allen, Kauai
38  Oahu Forest NWR, Oahu
30  Molokai
32  Lanai
33  Kahoolawe
36  Maalaea Bay, Maui
32  South Point, Big Island

Hawaii’s Mountains – Here’s a link to the live webcam on the summit of our tallest mountain Mauna Kea (nearly 13,800 feet high) on the Big Island of Hawaii. Here’s the webcam for the Haleakala Crater on Maui. These webcams are available during the daylight hours here in the islands, and at night whenever there’s a big moon shining down. Also, at night you will be able to see the stars — and the sunrise and sunset too — depending upon weather conditions.

Aloha Paragraphs

High pressure north of the state…providing our gusty trades

Deep clouds southwest…and far south of the state

Locally cloudy windward…clear to partly cloudy most leeward spots

Showers locally and offshore – Looping image

 

~~~ Hawaii Weather Narrative ~~~

Small Craft Advisory…windiest coasts and channels around Maui County and the Big Island
 

 

Broad Brush Overview: A moderately strong high pressure system, passing by to the north of the islands will keep our gusty trade wind flow active. The trades will back off some in strength Thursday and Thursday night, as a cold front passes by to the north of the state, then picking up a notch again over the weekend into early next week. Clouds and showers will favor windward and mountain areas as usual, with a few showers spilling over into leeward areas from time to time on the smaller islands.

Details:  This trade wind producing high pressure cell to the north of the state, will push steadily eastward, keeping the current trade wind episode in place across the island chain. Meanwhile, precipitable water values will remain slightly above normal for this time of year. This higher moisture content, combined with the strong and gusty trades, should keep scattered showers arriving along the windward sides, with a few isolated rain showers being carried into the leeward sides locally.

Looking Ahead: A cold front will pass by well to the north of the islands, resulting in a slight softening of the trade winds…into the moderate range Thursday and Thursday night. This cold front will stall well north of the islands Friday and Friday night, with a strong high pressure system building north of the state over the weekend. This should allow the trade winds to strengthen Friday and Friday night, with windy conditions then expected across the entire island chain over the weekend through early next week.

Here’s a wind profile of the Pacific Ocean – Closer view of the islands / Here’s the vog forecast animation / Here’s the latest weather map

Marine environment details: Strong trades will hold, as high pressure passes north of the state. A weakness in the ridge is forecast to develop through the second half of the work week, as a front passes to the north, which should cause slightly weaker trades Thursday and Thursday night. This weak spell will be short-lived, however, as a strong high is forecast to build north of the islands Friday through the weekend. Small craft advisory level trades will be expected across most waters beginning late Friday, which may near gale-force levels over the typically windier channels and waters around Maui County and the Big Island Saturday. This trend will likely hold into next week.

The small craft advisory currently in place over most waters due to a combination of winds and sea will be scaled back to only include the typically windier channels and waters around Maui County and the Big Island beginning tonight, as the large northwest swell that peaked continues to ease, and the winds begin to lower.

A moderate swell is expected out of the northwest by late tonight into Thursday, which will become reinforced by a larger source out of the same direction Friday into the weekend. Surf should remain below advisory levels Thursday with the initial swell, then potentially near warning levels Friday night into Saturday as the reinforcement arrives. Surf should trend down below advisory levels along north and west facing shores through the second half of the weekend…into early next week.

Surf along east facing shores will remain rough and choppy due to persistent trades locally and upstream of the state. Surf may near advisory levels over the upcoming weekend into early next week, as the trades strengthen.

Small south swells will continue to generate small surf along south facing shores through the week. A slightly larger south swell from recent activity over the southern Pacific may arrive late Sunday through early next week.

 

Kauai

World-wide Tropical Cyclone activity

Here’s the latest Pacific Disaster Center (PDC) Weather Wall Presentation the remnants of former TC 17P offshore from the Queensland coast of Australia

>>> Atlantic Ocean:

>>> Caribbean Sea:

>>> Gulf of Mexico:

Here’s a satellite image of the Caribbean Sea…and the Gulf of Mexico

Here’s the link to the National Hurricane Center (NHC)

>>> Eastern Pacific:

Here’s a wide satellite image that covers the entire area between Mexico, out through the central Pacific…to the International Dateline.

Here’s the link to the National Hurricane Center (NHC)

>>> Central Pacific:

Here’s a link to the Central Pacific Hurricane Center (CPHC)

>>> Northwest Pacific Ocean: No active tropical cyclones

>>> North and South Indian Oceans / Arabian Sea: No active tropical cyclones

Here’s a link to the Joint Typhoon Warning Center (JTWC)


Interesting: New Ocean Current Discovered Off the Coast of Madagascar – A previously unknown ocean current was recently discovered “by accident” off the coast of Madagascar, a rare find in the 21st century.

The newfound Southwest Madagascar Coastal Current could help researchers better predict the effects of climate change, said researchers involved in the study.

The world’s circulation system

Ocean currents are part of a giant circulation system that moves water, nutrients and heat around the globe. Though sailors had long known of these oceanic conveyor belts, the first truly systematic description of global currents was published in “The Physical Geography of the Sea” (Harper & Brothers, 1855) by Matthew Fontaine Maury, the head of the U.S. Navy’s Depot of Charts and Instruments.

Maury not only compiled data on current direction and strength using sailors’ logbooks, but he also discovered new currents by tossing messages in bottles out to sea, then tracking where they wound up, according to the Woods Hole Oceanographic Institution.

But finding completely unknown currents in modern times is rare.

“I think we’ve discovered most of the major currents. One of the reasons why this one was not known is that the region has been very much undersampled,” Marjolaine Krug, study co-author and a researcher at the Council for Scientific and Industrial Research in South Africa.

The Southwest Madagascar Coastal Current was a missing piece in scientists’ understanding of the world’s climate. And the researchers stumbled upon it by accident, they said.

“Like any research discovery, there is a bit of luck involved,” Krug said.

The team, which consisted of South African, Malagasy and French researchers, was investigating the strip of ocean between Mozambique and Madagascar, known as the Mozambique Channel. They noticed that there was water coming into the channel that couldn’t be explained by other known flow sources. Looking at satellite imagery, they discovered a completely new current carrying water along the Madagascar coast and then toward Earth’s poles.

In oceanic terms, the Southwest Madagascar Coastal Current is fairly small: At only 62 miles long and 330 yards deep, it transports about 264 million gallons of warm, salty water a second, or the equivalent of more than 500 Olympic swimming pools’ worth of water.

But the current’s location, rather than its size, makes it vital in understanding the world’s oceans, the researchers said.

The Mozambique Channel feeds the Agulhas Current, one of the strongest currents in the world. The Agulhas Current affects the path of tropical storms and carries heat toward higher latitudes, according to a 2016 Nature study. (The Agulhas Current also posed a challenge for Portuguese sailors circumnavigating Africa to get to India in the 15th century, according to oceancurrents.com.)

“The Agulhas is the equivalent of the Gulf Stream, but for [the] Southern Hemisphere,” Krug said.

So understanding the sources of the mighty Agulhas could help scientists better predict the effects of climate change, Krug said.

Krug said she suspects that other unknown currents might be swirling in the ocean. And even though we have discovered most of the ocean’s currents, there is a great deal we do not know, she said.

“There is still so much we have to discover about the connectivity of the ocean system,” Krug said. “And while we might have a good knowledge of most of the currents, there is still so much to be discovered about how these currents change.”

The study was published in the journal Geophysical Research Letters.