Air Temperatures – The following maximum temperatures (F) were recorded across the state of Hawaii Friday along with the low temperatures Saturday:
81 – 74 Lihue, Kauai
81 – 73 Honolulu, Oahu
82 – 74 Molokai AP
81 – 73 Kahului AP, Maui
85 – 72 Kailua Kona
81 – 65 Hilo AP, Hawaii
Here are the latest 24-hour precipitation totals (in inches) for each of the islands as of Saturday afternoon:
0.51 Mount Waialeale, Kauai
0.47 Palisades, Oahu
0.23 Molokai
0.00 Lanai
0.00 Kahoolawe
0.58 Mount Wailuaiki, Maui
2.02 Saddle Quarry, Big Island
The following numbers represent the strongest wind gusts (mph) as of Saturday afternoon:
33 Port Allen, Kauai
36 Oahu Forest NWR, Oahu
37 Molokai
29 Lanai
52 Kahoolawe
35 Kahului AP, Maui
43 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. This webcam is 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 to our north will continue to shield Hawaii from gales and storms, and their associated cold fronts
The area of heavy duty clouds remains west and southwest of Hawaii, sending high cirrus clouds over the islands from time to time…likely providing some nice color at sunset
These high cirrus clouds will dim and filter our sunshine at times during the day locally…with low clouds being carried ashore by the blustery trade winds from the east
Just a few showers falling along the windward sections…and offshore – Looping radar image
Small Craft Advisory…all Hawaiian coasts and channels (25-33 knots)
High Surf Advisory…east facing shores of Kauai, Oahu, Molokai, Maui and the Big Island
Gale Warning…Maalaea Bay, Pailolo and Alenuihaha Channels, along with waters south of the Big Island – (34-47 knots)
Wind Advisory…locally over ridge lines, downwind of steep terrain on the islands of Maui, Kahoolawe and the Big Island (20-35 mph with gusts over 50)
~~~ Hawaii Weather Narrative ~~~
Trade winds remaining strong and gusty…with a slight easing up Sunday into Tuesday morning. Here’s the latest weather map, showing a large area of high pressure north of Hawaii. This unusually windy weather will bring 50+ mph wind gusts to some areas of the island chain. These conditions are keeping a Wind Advisory in play over some parts of the island chain, along with Gale Warnings locally over the windiest coastal and channel waters. These blustery winds should begin to ease up later this weekend into early in the new week ahead. A cold front/trough will approach the islands, which should calm our winds down a little, veering them to the southeast or east-southeast…perhaps bringing some volcanic haze (vog) our way then. The trades are forecast to rebound over the islands later Tuesday through Thursday, then weakening some Friday into next weekend.
Here’s a wind profile of the offshore waters around the islands – and a closer look
Here’s the Hawaiian Islands Sulfate Aerosol animated graphic, showing vog forecast
Windward showers will continue to fall locally, while the leeward sides will see fewer showers. A windy trade wind weather pattern remains in place for the time being. There will be localized showery low clouds, in addition to thin streaks of high cirrus clouds passing over at times too. As we move into the mid-week time frame, an area of moisture is forecast to move over the state for a few days. As the trade winds will be blowing then, the bulk of these showers will impact the windward sides. These showers may become quite heavy…thanks to the arrival of an upper level trough of low pressure at about the same time. Looking even further out in time, we may see a possible second round of potential heavy showers arriving late next week into next weekend.
Marine environment details: The gale conditions are likely persisting over the typically windier zones around Maui County and the Big Island, and the Gale Warning for those areas remains posted through today. The Small Craft Advisory has been extended through Sunday for the remainder of the coastal waters.
East facing shores will continue to experience advisory level surf through this weekend. Surf is expected to ease slightly early in the new week ahead, in response to the winds trending down and shifting to the east-southeast or southeast. The High Surf Advisory for east facing shores has been extended through Sunday.
The ongoing small northwest swell will gradually subside. Another small northwest swell will arrive Sunday night and continue through about Tuesday. Resulting surf along north and west facing shores will remain well below advisory levels through this time.
Southern shores will see a slight increase in surf through the day Monday as a small south-southwest swell arrives. The surf should remain below advisory levels through this time, before easing through the mid-week period.
Friday Evening Film: The film that my friends Jeff and Svetlana and I saw last night was very good, called Allied. This action, adventure drama stars Brad Pitt, Marion Cotillard, Lizzy Caplan and Jared Harris…among many others. The synopsis: The story of intelligence officer Max Vatan (Brad Pitt), who in 1942 North Africa encounters French Resistance fighter Marianne Beausejour (Marion Cotillard) on a deadly mission behind enemy lines. Reunited in London, their relationship is threatened by the extreme pressures of the war.
Most of the critics are being reasonably kind to this film, although certainly not jumping out of their seats by any means. Nonetheless, I very much like the two main actors, and looking at the trailer (full screen viewing is best), it definitely caught my attention. There were so many shots of Pitt and Cotillard, although for my money, I never got tired of seeing them work together…a truly handsome couple! This film had me on the edge of my seat more than once, and I’ll admit, I had to try really hard to keep the tears at bay a couple of times as well. As it turned out, Jeff and I both gave this special film A- grades, with Svetlana giving it a strong B. As you’ll see if you look at the trailer, it’s not exactly a light weight piece of work! In the end, all that was left was a great sense of love, that swept me off my feet.
Don’t need a Weatherman to know which way the wind blows!
World-wide tropical cyclone activity…
>>> Atlantic Ocean: No active tropical cyclones
Here’s a satellite image of the Atlantic Ocean
>>> Caribbean: No active tropical cyclones
>>> Gulf of Mexico: No active tropical cyclones
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:
Former Tropical Cyclone 16L (Otto) is dissipating over the eastern Pacific, here’s the NHC graphical track map, with a satellite image – Final Advisory
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: No active tropical cyclones
Here’s a link to the Central Pacific Hurricane Center (CPHC)
>>> Northwest Pacific Ocean:
Tropical Storm 29W has moved out over the warm waters of the South China Sea, here’s the JTWC graphical track map, with a satellite image, and what the computer models are showing
>>> South 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: Saharan dust in the wind – Every year, trade winds over the Sahara Desert sweep up huge plumes of mineral dust, transporting hundreds of teragrams — enough to fill 10 million dump trucks — across North Africa and over the Atlantic Ocean. This dust can be blown for thousands of kilometers and settle in places as far away as Florida and the Bahamas.
The Sahara is the largest source of windblown dust to the Earth’s atmosphere. But researchers from MIT, Yale University, and elsewhere now report that the African plume was far less dusty between 5,000 and 11,000 years ago, containing only half the amount of dust that is transported today.
In a paper published today in Science Advances, the researchers have reconstructed the African dust plume over the last 23,000 years and observed a dramatic reduction in dust beginning around 11,000 years ago. They say this weakened plume may have allowed more sunlight to reach the ocean, increasing its temperature by 0.15 degrees Celsius — a small but significant spike that likely helped whip up monsoons over North Africa, where climate at the time was far more temperate and hospitable than it is today.
“In the tropical ocean, fractions of a degree can cause big differences in precipitation patterns and winds,” says co-author David McGee, the Kerr-McGee Career Development Assistant Professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It does seem like dust variations may have large enough effects that it’s important to know how big those impacts were in past and future climates.”
A wet Sahara
Around 11,000 years ago, the Earth had just emerged from the last ice age and was beginning a new, interglacial epoch known as the Holocene. Geologists and archaeologists have found evidence that during this period the Sahara was much greener, wetter, and more livable than it is today.
“There was also extensive human settlement throughout the Sahara, with lifestyles that would never be possible today,” McGee says. “Researchers at archaeological sites have found fish hooks and spears in the middle of the Sahara, in places that would be completely uninhabitable today. So there was clearly much more water and precipitation over the Sahara.”
This evidence of wet conditions shows that the region experienced regular monsoon rains during the early Holocene. This was primarily due to the slow wobbling of Earth’s axis, which exposed the Northern Hemisphere to more sunlight during summer; this, in turn, warmed the land and ocean and drew more water vapor — and precipitation — over North Africa. Increased vegetation in the Sahara may have also played a role, absorbing sunlight and heating the surface, drawing more moisture over the land.
“The mysterious thing is, if you try to simulate all these changes in these early and mid-Holocene climates, the models intensify the monsoons, but nowhere near the amounts suggested by the paleodata,” McGee says. “One of the things not factored into these simulations is changes in windblown dust.”
Tracking a dust plume
In their results published today, McGee and colleagues propose a reduction in African dust may indeed have contributed to increasing monsoon rains in the region. The researchers came to their conclusion after estimating the amount of long-range windblown dust emitted from Africa over the last 23,000 years, from the end of the last ice age to today.
They focused on dust transported long distances, as these particles are small and light enough to be lifted and carried through the atmosphere for days before settling thousands of kilometers away from their source. This fine-grained dust scatters incoming solar radiation, cooling the ocean’s surface and potentially affecting precipitation patterns, depending on how much dust is in the air.
To estimate how the African dust plume has changed over thousands of years, the team looked for places where dust should accumulate rapidly. Dust can sink to the floor of open ocean, but there layers of sediment build up very slowly, at a rate of 1 centimeter every 1,000 years.
Places like the Bahamas, by contrast, accumulate sediment much more quickly, making it easier for scientists to determine the ages of particular sediment layers. What’s more, it’s been shown that most of the windblown dust that has accumulated in the Bahamas originated not from local regions such as the U.S., but from the Sahara.
Dust’s climate role
McGee and his colleagues obtained sediment core samples from the Bahamas that were collected in the 1980s by scientists from the Woods Hole Oceanographic Institution. They brought the samples back to the lab and analyzed their chemical composition, including isotopes of thorium — an element that exists in windblown dust worldwide, at known concentrations.
They determined how much dust was in each sediment layer by measuring the primary isotope of thorium, and determined how fast it was accumulating by measuring the amount of a rare thorium isotope in each layer.
In this way, the team analyzed sediment layers from the last 23,000 years, and showed that around 16,000 years ago, toward the end of the last ice age, the dust plume was at its highest, lofting at least twice the amount of dust over the Atlantic, compared to today. However, between 5,000 and 11,000 years ago, this plume weakened significantly, with just half the amount of today’s windblown dust.
Colleagues at Yale University then plugged their estimates into a climate model to see how such changes in the African dust plume would affect both ocean temperatures in the North Atlantic and overall climate in North Africa. The simulations showed that a drop in long-range windblown dust would raise sea surface temperatures by 0.15 degrees Celsius, drawing more water vapor over the Sahara, which would have helped to drive more intense monsoon rains in the region.
“The modeling showed that if dust had even relatively small impacts on sea surface temperatures, this could have pronounced impacts on precipitation and winds both in the north Atlantic and over North Africa,” McGee says. Noting that the next key step is to reduce uncertainties in the modeling of dust’s climate impacts, he adds: “We’re not saying, the expansion of monsoon rains into the Sahara was caused solely by dust impacts. We’re saying we need to figure out how big those dust impacts are, to understand both past and future climates.”
Ina Tegen, a professor at the Leibniz Institute for Tropospheric Research in Germany, says the group’s results suggest that “dust effects today may be considerable as well.”
“Dust loads vary with changing climate, and due to the effects of dust on [solar] radiation, ice formation in clouds, and the carbon cycle, this may cause important climate feedbacks,” says Tegen, who was not involved in the research. “The changing climate since the last ice age can be considered a ‘natural laboratory’ to study such effects. Understanding the past is the basis for predicting future changes with any confidence.”