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

82 75  Lihue, Kauai
81 – 76  Honolulu, Oahu
8074  Molokai AP
85 – 75  Kahului AP, Maui
8879  Kailua Kona
89 73  Hawaii

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

2.57  Kilohana , Kauai
2.24  Makaha Stream, Oahu
7.83  Molokai

0.75  Lanai
0.07  Kahoolawe
9.02  West Wailuaiki, Maui
1.14  Kahua Ranch, Big Island

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

37  Lihue, Kauai
56  Oahu Forest NWR, Oahu
32  Molokai
25  Lanai
33  Kahoolawe
25  Maalaea Bay, Maui

27  Puho CS, Big Island

Hawaii’s MountainsHere’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 10,000+ feet high 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


http://www.ssd.noaa.gov/goes/west/tpac/avn-animated.gif
  Tropical Depression Olivia is moving away / click images to enlarge

 http://www.ssd.noaa.gov/goes/west/cpac/ir4.jpg

 The center of Olivia moved across Maui County, and is moving away from the state

http://www.prh.noaa.gov/cphc/tc_graphics/2018/graphics/EP172018_5day_cone_with_line_and_wind_51.png


http://www.ssd.noaa.gov/goes/west/hi/ir4.jpg

Partly to mostly cloudy…heavy clouds in the wake of Olivia
near and over the islands

 

http://www.prh.noaa.gov/hnl/satellite/State_VIS_loop.gif Olivia spins away to the southwest of Kauai

 

https://radar.weather.gov/Conus/RadarImg/hawaii.gif
Showers locally and offshore…some are heavy
Looping image

 

High Surf Advisory

Flash Flood Watch

Small Craft Advisory

Flood Advisory

 

~~~ Hawaii Weather Narrative ~~~

 

Broad Brush Overview: The center of Olivia moved across Maui County, and is southwest of Kauai…moving away from the state. As the system is still fairly close, expect the moisture to remain across the area. An upper level low will move close to the islands, resulting in a very unstable and unsettled period…lasting into Saturday. A drier air mass is expected to spread over the area the rest of the weekend into early next week.

Details: The deep convection (thunderstorms) associated with tropical depression Olivia separated from the lower level circulation, and is moving southwest past Kauai. Showers remain active across parts of the state today.

The threat of heavy rain will continue even when Olivia is well southwest of Kauai…even after the winds from Olivia have subsided. The heaviest rain will likely shift to Kauai today. A Flood Watch remains in effect for all islands through tonight.

Looking Ahead: Once Olivia clears the island chain, the atmosphere will gradually dry out and stabilize, as the moisture from Olivia and the low aloft move away to the west. This is likely to occur over the upcoming weekend.

Here’s a near real-time Wind Profile of the Pacific Ocean – along with a Closer View of the islands / Here’s the latest Weather Map / Here’s the latest Vog Forecast Animation / Here’s the Vog Information website

Marine Environmental Conditions:  Swell from Olivia has been spreading westward across the state. Lower surf is expected for east facing shores of Lanai and Kauai. Surf is expected to decline fairly rapidly as Olivia exits the local waters.

A small northwest swell is expected late in the weekend and early next week. No other significant swells are expected.



World-wide Tropical Cyclone Activity

 

Here’s the latest Pacific Disaster Center (PDC) Weather Wall Presentation covering the Atlantic Ocean, including Hurricane 06L (Florence), Hurricane 08L (Helene)Tropical Storm 09L (Isaac)…and Subtropical Storm 10L (Joyce)

Here’s the latest Pacific Disaster Center (PDC) Weather Wall Presentation covering the Pacific and Indian Oceans, including Tropical Depression 17E Olivia, Supertyphoon 26W (Mangkhut)and Tropical Storm 27W (Barijat)


>>> Atlantic Ocean:

Hurricane 06L (Florence)

https://www.nhc.noaa.gov/storm_graphics/AT06/refresh/AL062018_5day_cone_with_line_and_wind+png/205721_5day_cone_with_line_and_wind.png

https://cdn.star.nesdis.noaa.gov/GOES16/ABI/CONUS/07/1250x750.jpg

 https://cdn.star.nesdis.noaa.gov/GOES16/ABI/SECTOR/eus/13/1000x1000.jpg

https://www.nhc.noaa.gov/storm_graphics/AT06/refresh/AL062018_earliest_reasonable_toa_no_wsp_34+png/024408_earliest_reasonable_toa_no_wsp_34.png

Here’s what the computer models are showing

According to the NHC Advisory 55…Florence is moving toward the northwest near 17 mph, and this general motion, accompanied by a gradual decrease in forward speed, is expected to continue through Thursday. A turn to the west-northwest and west at an even slower forward speed is expected Thursday night and Friday, and a slow west-southwestward motion is forecast Friday night and Saturday. On the forecast track, the center of Florence will approach the coasts of North and South Carolina on Thursday, then move near or over the coast of southern North Carolina and eastern South Carolina in the hurricane warning area on Thursday night and Friday. A slow motion over eastern South Carolina is forecast Friday night and Saturday.

Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have decreased to near 110 mph with higher gusts. Florence is now a category 2 hurricane on the Saffir-Simpson Hurricane Wind scale. Little change in strength is expected before the center reaches the coast, with weakening expected after the center moves inland. Hurricane-force winds extend outward up to 80 miles from the center and tropical-storm-force winds extend outward up to 195 miles.

Hurricane 08L (Helene)

Here’s what the computer models are showing

According to the NHC Advisory 23…Helene is moving toward the north near 13 mph. A turn toward the north-northeast with an increase in forward speed is expected Thursday night followed by a turn toward the northeast over the weekend. Maximum sustained winds have decreased to near 80 mph with higher gusts. Continued weakening is forecast over the next couple of days, and Helene is expected to become a tropical storm on Thursday. Hurricane-force winds extend outward up to 45 miles from the center and tropical-storm-force winds extend outward up to 175 miles.

 

Tropical Storm 09L (Isaac)

Here’s what the computer models are showing

According to the NHC Advisory 22…Isaac is moving toward the west near 20 mph, and this general motion with a decrease in forward is expected to continue through the weekend. On the forecast track, Isaac is forecast to move across the central Lesser Antilles and into the eastern Caribbean Sea on Thursday, and then move across the eastern and central Caribbean Sea through the weekend. Data from a NOAA Hurricane Hunter aircraft and satellite-derived wind data indicate that the maximum sustained winds have decreased to near 50 mph with higher gusts. A gradual decrease in the winds is forecast during the next 48 hours. Tropical-storm-force winds extend outward up to 175 miles to the north of the center.

Sub-Tropical Storm 10L (Joyce)

Here’s what the computer models are showing

According to the NHC Advisory 2…The storm is moving toward the southwest near 6 mph. A slow southwestward motion is expected for the next couple of days. A turn toward the northeast with a rapid increase in forward motion is forecast to occur over the weekend. Maximum sustained winds are near 45 mph with higher gusts. Some slight strengthening is forecast during the next 48 hours. Joyce is forecast to become a tropical storm within the next day or so. Winds of 40 mph extend outward up to 115 miles from the center, mainly to the northwest.

 

>>> 1.) A broad area of low pressure is located over the central Gulf of Mexico. Although the shower activity is still disorganized, upper-level winds are forecast to become more conducive for development, and it is likely that a tropical depression will form Thursday or Thursday night, before the system reaches the western Gulf coast. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate the disturbance tomorrow, if necessary. Regardless of development, heavy rainfall and gusty winds are expected across portions of northeastern Mexico, Texas, and Louisiana late this week.

* Formation chance through 48 hours…high…70 percent
* Formation chance through 5 days…high…70 percent

2.) An area of low pressure is expected to develop near Bermuda late this weekend or early next week. Some gradual development is possible after that time while the system drifts westward over the western Atlantic.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 5 days…low…20 percent

>>> 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:

1.) A broad area of low pressure appears to have formed about 100 miles west-southwest of Cabo Corrientes, Mexico, however the associated shower and thunderstorm activity has not changed much in organization since earlier today. Although upper-level winds are only marginally conducive, some development of this system is possible over the next few days while the disturbance moves slowly toward the west-southwest away from the coast of Mexico.

* Formation chance through 48 hours…low…30 percent
* Formation chance through 5 days…medium…40 percent

2.) An area of low pressure is expected to develop well south of the southwestern coast of Mexico by the weekend. Thereafter, environmental conditions appear conducive for some development, and a tropical depression could form while the system moves generally westward to west-northwestward south of Mexico.

* Formation chance through 48 hours…low…near 0 percent
* Formation chance through 5 days…medium…40 percent

>>> Central Pacific:

Tropical Depression 17E (Olivia) 

Here’s what the computer models are showing


According to the CPHC Advisory 51…The depression is moving toward the west-southwest near 18 mph (30 km/h), and this general motion is expected to continue through early Thursday with a slight decrease in forward speed, followed by a turn toward the west late Thursday. Olivia, or its remnant low, is forecast to turn toward the west-northwest on Friday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Little change in strength is forecast through Thursday evening. Olivia is expected to become a post-tropical remnant low late Thursday night or Friday.

HAZARDS AFFECTING LAND –

RAINFALL: Areas of heavy rainfall will likely persist through Thursday night. Moisture associated with Olivia is expected to produce total rainfall accumulations of 5 to 10 inches in some areas, with isolated amounts of up to 15 inches, especially over higher terrain. This rainfall may produce life-threatening flash flooding. Nine inches of rain have already fallen over parts of Maui.

SURF: Large swells generated by Olivia will impact parts of the main Hawaiian Islands. This will result in dangerous surf along east facing shores

>>> Northwest Pacific Ocean:

Supertyphoon 26W (Mangkhut)

JTWC textual advisory
JTWC graphical track map

Tropical Storm 27W (Barijat)

JTWC textual advisory
JTWC graphical track map

>>> 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: Here’s How to Make the Sahara Desert Green Again – The Sahara is the world’s largest hot desert, but parts of it could be made green if massive solar and wind farms set up shop there, a new study finds.

These farms could increase rain in the Sahara, especially in the neighboring Sahel region, a semiarid area that lies south of the giant desert, the researchers said in the study, which was published online Sept. 7 in the journal Science.

“This increase in precipitation, in turn, leads to an increase in vegetation cover, creating a positive feedback loop,” study co-lead researcher Yan Li, a postdoctoral researcher in natural resources and environmental sciences at the University of Illinois, said in a statement.

Researchers already knew that wind and solar farms can increase the heat and humidity in the areas immediately around them. But this study is among the first to model how wind and solar farms would affect the Sahara, all while considering how growing green plants and trees would respond to these changes, said Li, who started the study while a postdoctoral researcher in the Department of Atmospheric and Oceanic Science at the University of Maryland.

“Previous modeling studies have shown that large-scale wind and solar farms can produce significant climate change at continental scales,” Li said. “But the lack of vegetation feedbacks could make the modeled climate impacts very different from their actual behavior.”

Li and his colleagues simulated what would happen if wind and solar farms covered more than 3.4 million square miles of the Sahara. On average, the wind farms would generate about 3 terawatts, while the solar farms would generate 79 terawatts of electrical power in one year, they found.

That’s a lot of energy. One terawatt can power about 10 billion 100-watt light bulbs simultaneously. “In 2017, the global energy demand was only 18 terawatts, so this is obviously much more energy than is currently needed worldwide,” Li said.

The model also showed that wind farms caused localized air temperatures to warm.

“Greater nighttime warming takes place because wind turbines can enhance the vertical mixing and bring down warmer air from above,” the researchers wrote in the study. Rain also increased as much as 0.01 inches per day, on average, in areas with wind farms, the researchers found.

“This was a doubling of precipitation over that seen in the control experiments,” Li said.

The Sahel would see even more rain; an increase of 0.04 inches a day in areas with wind farms, which would help vegetation there grow, the researchers said. That translates to an increase of between 8 and 20 inches of rain a year in the Sahel, enough that it would not be classified as a desert. (Deserts, by definition, are areas that receive less than 10 inches of annual rainfall.)

The solar farms would also have a positive effect on temperature and rainfall, the researchers noted.

“We found that the large-scale installation of solar and wind farms can bring more rainfall and promote vegetation growth in these regions,” study co-lead researcher Eugenia Kalnay, a distinguished professor in the Department of Atmospheric and Oceanic Science at the University of Maryland, said in the statement. “The rainfall increase is a consequence of complex land-atmosphere interactions that occur because solar panels and wind turbines create rougher and darker land surfaces.”

If this model ever becomes a reality, “the increase in rainfall and vegetation, combined with clean electricity as a result of solar and wind energy, could help agriculture, economic development and social well-being in the Sahara, Sahel, Middle East and other nearby regions,” Safa Motesharrei, a systems scientist at the University of Maryland, said in the statement.

“The Sahara has been expanding for some decades, and solar and wind farms might help stop the expansion of this arid region,” Russ Dickerson, a leader on air quality research and a professor at the Department of Atmospheric and Oceanic Science at the University of Maryland who was not involved in the study, said in a statement. “This looks like a win-win to me.”