Air Temperatures – The following maximum temperatures (F) were recorded across the state of Hawaii Wednesday…and the low temperatures Wednesday:
80 – 66 Lihue, Kauai
84 – 72 Honolulu, Oahu
78 – 67 Molokai AP
82 – 69 Kahului AP, Maui
82 – 72 Kailua Kona
80 – 71 Hilo AP, Hawaii
Here are the latest 24-hour precipitation totals (inches) for each of the islands…as of Wednesday evening:
0.15 Kilohana, Kauai
1.01 Tunnel RG, Oahu
1.87 Puu Alii, Molokai
0.04 Lanai
0.00 Kahoolawe
9.30 West Wailuaiki, Maui!
4.10 Honokaa, Big Island
The following numbers represent the strongest wind gusts (mph)…as of Wednesday evening:
22 Poipu, Kauai – NNE
29 Oahu Forest NWR, Oahu – SE
16 Molokai – N
27 Lanai – NE
28 Kahoolawe – NNE
24 Kapalua, Maui – N
22 Upolu AP, Big Island – ENE
Hawaii’s Mountains – Here’s a link to the live web cam on the summit of near 13,800 foot Mauna Kea on the Big Island of Hawaii. This web cam is available during the daylight hours here in the islands…and when there’s a big moon shining down during the night at times. Plus, during the nights you will be able to see stars, and the sunrise and sunset too…depending upon weather conditions.
Aloha Paragraphs
A low pressure system over the ocean to the northeast…along with its
ragged frontal cloud band draping southwest from its center
What’s left of a late season cold front remains over the Big Island…
an area of thunderstorms to the southwest
Most clouds hugging the windward sides, with clear to partly
cloudy skies leeward…high cirrus southwest
Showers falling locally…mostly over and around the Big Island
Looping radar image
~~~ Hawaii Weather Narrative ~~~
Northeasterly trade winds, moderately strong…then turning lighter Thursday through the weekend. Here’s the latest weather map, showing high pressure systems to the northwest. At the same time, there’s a very weak low pressure system to the northeast…with the tail-end of an old cold front over Maui and the Big Island. The air flow over the state is generally from the trade wind direction. These trades should remain moderately strong, before weakening Thursday and Friday…into the weekend. Early next week the trades will strengthen…settling right back into the moderately strong realms.
Here’s a wind profile…of the offshore waters around the islands – with a closer view
Here’s the Hawaiian Islands Sulfate Aerosol animated graphic – showing vog forecast
Moisture over the islands will prevail, with the bulk of it focused over the Big Island now. We can expect showers over mainly windward areas, especially over the Big Island. The models indicate an upper level low pressure system passing over the islands this weekend, which should prompt a surface trough over the state. As a result, weak winds will veer to the east-southeast and move the remnant frontal moisture, hung up near the Big Island now…back over the other islands. A light wind flow then would allow for daytime sea breezes to blow, bringing showers to the leeward upcountry areas during the afternoons…perhaps locally quite heavy in some locations. The trade winds will pick up early next week, carrying more passing showers to the windward sides then.
The recent rainy weather has been a boon for the state, as we head towards our typically dry summer period, with a distinct emphasis over the windward coasts and slopes…although not exclusively. A late season cold front this past weekend brought the moisture carried by this frontal boundary, into the state from the northwest. The islands of Kauai and Oahu got some impressive rainfall totals as it crossed over those western islands. This front weakened as it dipped further into the state, finally stalling over the eastern Islands, and most directly over Maui. The last four days has seen 41.85″ of rainfall drop into the gauge at West Wailuaiki…which is not far inland from the Keanae Peninsula of east Maui. This was by far the largest rainfall total, although many areas around Maui picked up lots of rainfall too.
In contrast, here at my weather tower in Kula, we’ve been what we considered unusually wet, and we’ve had a bit over 3.00″ of precipitation. What’s left of this old front is now hung up over the Big Island, so the focus should remain there over the next day or two. The winds are expected to weaken through the rest of the week, and at the same time, we’ll find our atmosphere become destabilized by the weekend. This will lead to more showers, with both the windward and leeward sides getting locally wet again…some of these showers will be locally heavy. As we move into next week, the focus for showers will migrate back over to the windward sides of the islands.
Marine environment details: A small craft advisory (SCA) is in effect for some of the windier waters around Maui and the Big Island through tonight. The trades will weaken on Thursday, and winds and seas are expected to remain below headline thresholds through the remainder of the week. Strengthening trades will likely result in a need for small craft advisories across the typically windier waters Sunday night through the middle of next week.
Surf along all shores will remain below advisory levels. A small northwest swell is expected to arrive Friday, then slowly decline over the weekend. South shores will continue to see small swells, with a small bump expected to arrive late Monday.
Nice sunrise colors possible Thursday
Here on Maui – Before sunrise on this Wednesday morning, we find cloudy skies…along with showers falling locally. Meanwhile, it looks clear to partly cloudy, with much better weather over on the leeward sides! Here at my place in Kula, it’s been lightly raining with breezy conditions through most of the night. The air temperature at my weather tower was 58.1F degrees at 530am. At about the same time, it was cloudy with rain falling in Kahului at the airport, with an air temperature of 70 degrees…and 43 degrees atop the Haleakala Crater. / Now at 840am, it’s sunny here in Kula, although there are low clouds all around the edges, with a rainbow just down the mountain from here.
– Early afternoon, and today is much different than the last 3-4 days, in that…it isn’t drizzling or showering. There are lots of clouds around, although there’s a fair amount of clear blue skies too.
– Early evening, with mostly clear skies, although low clouds are evident around the edges in some locations. Meanwhile, we now have an area of high level cirrus clouds (made up of ice crystals), that are arriving from the south. These clouds are rather famous for providing colorful sunsets, so keep an eye out. If they are still around by sunrise Thursday, we could look for more color then.
World-wide tropical cyclone activity:
>>> Atlantic Ocean: The last regularly scheduled Tropical Weather Outlook of the 2015 Atlantic hurricane season…has occurred. Routine issuance of the Tropical Weather Outlook will resume on June 1, 2016. During the off-season, Special Tropical Weather Outlooks will be issued if conditions warrant. Here’s the 2015 hurricane season summary
Here’s a satellite image of the Atlantic Ocean
>>> Caribbean Sea: The last regularly scheduled Tropical Weather Outlook of the 2015 Atlantic hurricane season…has occurred. Routine issuance of the Tropical Weather Outlook will resume on June 1, 2016. During the off-season, Special Tropical Weather Outlooks will be issued if conditions warrant.
>>> Gulf of Mexico: The last regularly scheduled Tropical Weather Outlook of the 2015 Atlantic hurricane season…has occurred. Routine issuance of the Tropical Weather Outlook will resume on June 1, 2016. During the off-season, Special Tropical Weather Outlooks will be issued if conditions warrant.
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: The last regularly scheduled Tropical Weather Outlook of the 2015 North Pacific hurricane season…has occurred. Routine issuance of the Tropical Weather Outlook will resume on May 15, 2016. During the off-season, Special Tropical Weather Outlooks will be issued if conditions warrant. Here’s the 2015 hurricane season summary
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: The central north Pacific hurricane season has officially ended. Routine issuance of the tropical weather outlook will resume on June 1, 2016. During the off-season, special tropical weather outlooks will be issued if conditions warrant. Here’s the 2015 hurricane season summary
Here’s a link to the Central Pacific Hurricane Center (CPHC)
>>> 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: Early Earth’s air weighed less than half of today’s atmosphere – The idea that the young Earth had a thicker atmosphere turns out to be wrong. New research from the University of Washington uses bubbles trapped in 2.7 billion-year-old rocks to show that air at that time exerted at most half the pressure of today’s atmosphere.
The results, published online May 9 in Nature Geoscience, reverse the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for weaker sunlight. The finding also has implications for which gases were in that atmosphere, and how biology and climate worked on the early planet.
“For the longest time, people have been thinking the atmospheric pressure might have been higher back then, because the sun was fainter,” said lead author Sanjoy Som, who did the work as part of his UW doctorate in Earth and space sciences. “Our result is the opposite of what we were expecting.”
The idea of using bubbles trapped in cooling lava as a “paleobarometer” to determine the weight of air in our planet’s youth occurred decades ago to co-author Roger Buick, a UW professor of Earth and space sciences. Others had used the technique to measure the elevation of lavas a few million years old. To flip the idea and measure air pressure farther back in time, researchers needed a site where truly ancient lava had undisputedly formed at sea level.
Their field site in Western Australia was discovered by co-author Tim Blake of the University of Western Australia. There, the Beasley River has exposed 2.7 billion-year-old basalt lava. The lowest lava flow has “lava toes” that burrow into glassy shards, proving that molten lava plunged into seawater. The team drilled into the overlying lava flows to examine the size of the bubbles.
A stream of molten rock that forms a lava quickly cools from top and bottom, and bubbles trapped at the bottom are smaller than those at the top. The size difference records the air pressure pushing down on the lava as it cooled, 2.7 billion years ago.
Rough measurements in the field suggested a surprisingly lightweight atmosphere. More rigorous x-ray scans from several lava flows confirmed the result: The bubbles indicate that the atmospheric pressure at that time was less than half of today’s.
Earth 2.7 billion years ago was home only to single-celled microbes, sunlight was about one-fifth weaker, and the atmosphere contained no oxygen. But this finding points to conditions being even more otherworldly than previously thought. A lighter atmosphere could affect wind strength and other climate patterns, and would even alter the boiling point of liquids.
“We’re still coming to grips with the magnitude of this,” Buick said. “It’s going to take us a while to digest all the possible consequences.”
Other geological evidence clearly shows liquid water on Earth at that time, so the early atmosphere must have contained more heat-trapping greenhouse gases, like methane and carbon dioxide, and less nitrogen.
The new study is an advance on the UW team’s previous work on “fossilized raindrops” that first cast doubt on the idea of a far thicker ancient atmosphere. The result also reinforces Buick’s 2015 finding that microbes were pulling nitrogen out of Earth’s atmosphere some 3 billion years ago.
“The levels of nitrogen gas have varied through Earth’s history, at least in Earth’s early history, in ways that people just haven’t even thought of before,” said co-author David Catling, a UW professor of Earth and space sciences. “People will need to rewrite the textbooks.”
The researchers will next look for other suitable rocks to confirm the findings and learn how atmospheric pressure might have varied through time.
While clues to the early Earth are scarce, it is still easier to study than planets outside our solar system, so this will help understand possible conditions and life on other planets where atmospheres might be thin and oxygen-free, like that of the early Earth.
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