Air Temperatures – The following maximum temperatures (F) were recorded across the state of Hawaii Thursday…along with the minimums Thursday:
82 – 74 Lihue, Kauai
83 – 71 Honolulu, Oahu
84 – 66 Molokai AP
90 – 66 Kahului AP, Maui – tied the record Thursday…set back in 1984
85 – 73 Kailua Kona
84 – 68 Hilo AP, Hawaii
Here are the latest 24-hour precipitation totals (inches) for each of the islands…as of Thursday evening:
4.55 Mount Waialeale, Kauai
0.74 Kahuku Training Area, Oahu
0.03 Puu Alii, Molokai
0.09 Kula 1, Maui
0.22 Kawainui Stream, Big Island
The following numbers represent the strongest wind gusts (mph)…as of Thursday evening:
18 Moloaa Dairy, Kauai – SE
18 Oahu Forest NWR, Oahu – NW
17 Molokai – ESE
08 Lanai – S
25 Kahoolawe – E
22 Kahului Gap, Maui – NNE
23 Hilo AP, Big Island – NNE
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.
Thunderstorms far south through southwest…with
a cold front approaching Hawaii to the northwest
Clear to partly cloudy, with large cloudy areas locally
Showers falling locally – Looping radar image
~~~ Hawaii Weather Narrative ~~~
Trades winds easing up today into Friday, turning southeast to south…then returning trade winds during the upcoming weekend. Here’s the latest weather map, showing the Hawaiian Islands, and the rest of the North Pacific Ocean. We find a high pressure system well offshore to the northeast of the state. At the same time, we see a gale low pressure system far north, along with its trailing cloud band draping southwest into another weaker low pressure system just north of Hawaii. Trade winds have given way to southeasterly breezes, as this next cold front approaches the state. As this happens, we’ve seen our winds become lighter, remaining through Saturday morning. When these winds swing around to these directions…we’re very apt to see increased volcanic haze arriving over the smaller islands. The trade winds should return later in the weekend, ventilating the vog away then. The trade winds are slated to remain active through most if not all of next week.
Here’s the Hawaiian Islands Sulfate Aerosol animated graphic – showing vog forecast
As the breezes become lighter from the southeast…muggy weather will prevail through Friday. As a result of this lighter wind flow with onshore sea breezes during the days, we’ll see afternoon interior clouds forming over the islands again on Friday. This will lead to localized upcountry showers, some of which may be locally heavy on some of the islands into the early evening hours. The forecast calls for another late season cold front approaching the islands later Friday into Saturday. The models show this frontal boundary weakening into a surface trough of low pressure, as it moves into the state…likely stalling over the eastern islands later Saturday. Then, as a northeasterly air flow arrives in the wake of the frontal boundary, we’ll find some shower activity along the windward sides for several days into next week.
Marine environment details: A small west-northwest swell will persist through Friday. A reinforcing small north- northwest swell will arrive Saturday and last through the weekend.
A small south swell will maintain surf along south facing shores tonight. A new south swell will arrive Friday and peak late Saturday above the seasonal south swell average, and then slowly subside into early next week. While surf will be elevated, surf heights are expected to remain just below the high surf advisory criteria along south facing shores.
Trade winds building in later this weekend and next week will marginally boost surf heights along east facing shores. No high surf or small craft advisory are in effect…or expected through Friday.
Here on Maui – Before sunrise on this Thursday morning, we find partly cloudy skies along the windward coasts and slopes…stretching up over the West Maui mountains. By the way, there was another sugar cane fire early this morning, which has put smoke in the air this morning…above the central valley. Elsewhere around the island, skies were mostly clear. Here in upcountry Kula, it was calm and clear, with an air temperature at my weather tower of 50.3F degrees. At near the same time, the Kahului AP was reporting 67 degrees under clear skies, while it was 72 out in Hana and at Maalaea Bay…with a 46 degree reading atop the Haleakala Crater. / Now at 840am, it’s mostly sunny in all directions. Looking down into the central valley, I’m not sure if its leftover smoke from the early morning sugar cane burn…or light volcanic haze is beginning to arrive?
– Early afternoon, with the beaches still mostly sunny, and clouds forming over and around the mountains, rather robustly in some locations. The long lasting trade winds have switched off, or at least calmed down quite a bit…as expected. Here in upcountry Kula, at my place, it’s mostly cloudy, and seems to be working towards showers again this afternoon.
– Early evening under partly to mostly cloudy skies, along with a few scattered showers around the edges…mostly around the mountains. It looks like there’s a light haze trying to become established, which should be thicker on Friday. We had a few light showers this afternoon here in Kula, but they held off until late in the day, and weren’t impressive in terms of intensity…by any means.
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.
>>> 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: Greenland’s ice sheet not losing ice in its interior – Scientists studying data from the top of the Greenland ice sheet have discovered that during winter in the center of the world’s largest island, temperature inversions and other low-level atmospheric phenomena effectively isolate the ice surface from the atmosphere — recycling water vapor and halting the loss or gain of ice.
A team of climate scientists made the surprising discovery from three years of data collected at Summit Camp, an arid, glaciated landscape 10,500 feet above sea level in the middle of the Greenland ice sheet.
“This is a place, unlike the rest of the ice sheet, where ice is accumulating,” says Max Berkelhammer, assistant professor of earth and environmental sciences at the University of Illinois at Chicago. Berkelhammer is first author on the study, reported in Science Advances, an open-access online publication of the journal Science.
Near Greenland’s coasts, Berkelhammer said, “it’s relatively warm, and the ice melts faster and faster.”
“But in the center of the ice sheet, it’s 25 below zero Celsius (-13 F), so it’s always freezing, even if it warms. It’s a very rare occurrence to go above freezing,” he said. The authors note that “despite rapid melting in the coastal regions of the ice sheet, a significant area — approximately 40 percent — rarely experiences surface melting.”
Solid ice can be lost not only by melting into liquid water. Under certain conditions, it can vaporize by sublimation, a one-step transition from solid to gas. Such conditions exist at the high-altitude, dry, frigid, glacial surface of Greenland’s interior.
“Sublimation is common there, unlike other places,” Berkelhammer said. “We looked at the exchange of water between the ice sheet and the air above it through condensation, evaporation, and sublimation.”
At Summit Camp, a 150-foot tower was used to draw air samples at various heights above the surface and pipe the air into a laboratory buried a few feet below the ice. Lasers analyzed the air for two different isotopes of oxygen in H2O, whose ratio indicates the temperature at which the water molecules became airborne.
“We noticed a specific process that was occurring, where low-level fog would form right above the surface of the ice sheet,” Berkelhammer said. A fogbow — a rainbow caused by fog — often appeared.
“As ice sublimates from the surface, it forms a fog,” he said. “As the particles get heavier and settle back to the surface, you get recycling, rather than dissipation that would remove ice.”
In winter, 80 percent of the ice that would otherwise be lost is recycled, Berkelhammer said. “So it’s an incredibly efficient process.”
But many questions remain as to how this boundary-layer recycling contributes to models of climate change.
“We expected sublimation to increase with temperature, but we find no net loss” of ice over time, Berkelhammer said, again referring just to the interior of the ice mass. “You could say, if this process changes, you’d lose ice significantly faster. Or, if (recycling) becomes even more efficient, you would conserve even more ice mass.
“We can’t predict,” he said. “And we don’t know from the ice-core records what the history is.”
The next step, he said, is to run experiments to see how sublimation changes with temperature associated with past and future changes in atmospheric carbon dioxide levels, to see how recycling fits into climate models.
“If we want to model how the ice sheet is warming, we need to include everything we know,” he said. “This is a new process to incorporate in models.”
But Berkelhammer cautions against over-interpreting the recycling as good news for the ice sheet or the planet, as its overall effect is likely to be relatively minor.
“This is small potatoes compared to the calving that’s going on along the coasts,” he said. “Every time we go back to Greenland, the edge of the ice is farther away from the coast.”