Air Temperatures – The following maximum temperatures were recorded across the state of Hawaii Tuesday:
Lihue, Kauai – 82
Honolulu airport, Oahu – 86 (record for Tuesday – 92 in 1995)
Kaneohe, Oahu – 80
Molokai airport – 86
Kahului airport, Maui – 86 (record for Tuesday – 92 in 1969)
Kona airport 82
Hilo airport, Hawaii – 72
Air Temperatures ranged between these warmest and coolest spots near sea level – and on the highest mountain tops…as of 5pm Tuesday evening:
Barking Sands, Kauai – 85
Hilo, Hawaii – 75
Haleakala Crater – 48 (near 10,000 feet on Maui)
Mauna Kea Summit – 43 (over 13,500 feet on the Big Island)
Here are the 24-hour precipitation totals (inches) for each of the islands as of Tuesday evening:
1.15 Mount Waialeale, Kauai
0.95 Oahu Forest NWR, Oahu
0.00 Molokai
0.00 Lanai
0.00 Kahoolawe
0.11 Puu Kukui, Maui
1.45 Kawainui Stream, Big Island
Marine Winds – Here’s the latest (automatically updated) weather map showing high pressure systems to the north through north-northwest of our islands. Our local trade winds will remain active Wednesday and Thursday…blowing generally in the moderately strong category during the days.
Satellite and Radar Images: To view the cloud conditions we have here in Hawaii, please use the following satellite links, starting off with this Infrared Satellite Image of the islands to see all the clouds around during the day and night. This next image is one that gives close images of the islands only during the daytime hours, and is referred to as a Close-up visible image. Finally, here's a Looping IR satellite image, making viewable the clouds around the islands 24 hours a day. To help you keep track of where any showers may be around the islands, here’s the latest animated radar image.
Hawaii’s Mountains – Here’s a link to the live web cam on the summit of near 13,500 foot Mauna Kea on the Big Island of Hawaii. The tallest peak on the island of Maui is the Haleakala Crater, which is near 10,000 feet in elevation. These two web cams are 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.
Tropical Cyclone activity in the eastern and central Pacific – Here’s the latest weather information coming out of the National Hurricane Center, covering the eastern north Pacific. You can find the latest tropical cyclone information for the central north Pacific (where Hawaii is located) by clicking on this link to the Central Pacific Hurricane Center. A satellite image, which shows the entire ocean area between Hawaii and the Mexican coast…can be found here. Here's a tropical cyclone tracking map for the eastern and central Pacific.
Aloha Paragraphs
Good Weather…trade winds blowing
The trade winds will continue to blow through the rest of this week, generally in the moderately strong category…although locally lighter next Monday and Tuesday. Glancing at this weather map, we find our primary high pressure systems located to our north through north-northwest Tuesday night. The placement of these high pressure areas, and their associated ridges, will keep our trade winds blowing.
Our trade winds will remain active…the following numbers represent the strongest gusts, along with directions Tuesday evening:
27 Port Allen, Kauai – NE
24 Waianae, Oahu – NE
22 Molokai – NE
27 Kahoolawe – SE
30 Kahului, Maui – ENE
08 Lanai – NE
27 South Point, Big Island – NE
We can use the following links to see what’s going on in our area of the north central Pacific Ocean Tuesday night. Looking at this NOAA satellite picture we find high cirrus clouds moving through the island chain….from Oahu down to Maui County to the Big Island at the time of this writing. We can use this looping satellite image to see low clouds being carried towards our windward sides by the trade winds. The upper level low pressure system continues to spin far to our northwest. We find an area of high cirrus clouds stretching into the state from the west…with more taking aim on our islands further to the west. Checking out this looping radar image we see a few showers being carried along in the trade wind flow, falling especially across the windward sides.
Sunset Commentary: The trade winds continue to headline our local Hawaiian Island weather picture. High pressure systems located generally to our north through northwest, are the source of this moderately strong flow. Passing showers will continue to bring moisture at times along our windward coasts and slopes, generally at night and during the early morning hours…although not exclusively. Today’s radar also shows some showers having formed along the leeward side of the Big Island and Oahu…in the upcountry areas locally. These passing showers however, at least according to this radar image, aren’t amounting to all that much, at least at the time of this writing.
The computer models don’t suggest any wild swings in our weather conditions through the rest of the week. Generally moderately strong trade winds will prevail, along with small surf, and those common early summer showers at times. Perhaps the next thing that we’ll notice will be the lighter trade winds later this holiday weekend, and the limited showers then too. We don’t like to see our trade winds get too light on the night of July 4th of course, with all the fireworks smoke going up in the air then!
At 515pm Tuesday evening here in Kihei, Maui, the weather was about like it is most evenings at this time, being partly cloudy. The majority of the clouds were hugging the mountain slopes, with some spreading down towards the coasts locally. The windward sides have some clouds too, which is very common when we have the trade winds blowing. I'm just about ready to take the drive back upcountry to Kula, where its cloudy. I'll get out for my evening constitutional, my walk shortly thereafter. I'll then have some dinner, do some reading, and hit the hay. I'll be up again early Wednesday morning, in time to prepare your next weather narrative, coming out around 530am HST, before getting ready to drive back down to Kihei for work tomorrow. I hope you have a great Tuesday night until then! Aloha for now…Glenn.
Interesting: Hawks and albatrosses soar for hours or even days without having to land. Soon robotic gliders could go one better, soaring on winds and thermals indefinitely. Cheap remote sensing for search and rescue would be possible with this technology, or it could be used to draw up detailed maps of a battlefield. Glider pilots are old hands at using rising columns of heated air to gain altitude.
In 2005 researchers at NASA's Dryden Flight Research Center in Edwards, California, flew a glider fitted with a custom autopilot unit 60 minutes longer than normal, just by catching and riding thermals. And in 2009 Dan Edwards, who now works at the US Naval Research Laboratory in Washington DC, kept a glider soaring autonomously for 5.3 hours this way.
Both projects relied on the glider to sense when it was in a thermal and then react to stay in the updraft. But thermals can be capricious, and tend to die out at night, making flights that last several days impossible, says Salah Sukkarieh of the Australian Centre for Field Robotics in Sydney.
He is designing an autopilot system that maps and plans a glider's route so it can use a technique known as dynamic soaring when thermals are scarce. The glider first flies in a high-speed air current to gain momentum, then it turns into a region of slower winds, where the newly gained energy can be converted to lift. By cycling back and forth this way, the glider can gain either speed or altitude.
"Theoretically you can stay aloft indefinitely, just by hopping around and catching the winds," says Sukkarieh, who presented his research at a robotics conference in Shanghai, China, last month. Inspired by albatrosses and frigate birds, the operators of radio-controlled gliders have used dynamic soaring to reach speeds of more than 600 kilometers per hour by flying between two regions of differing wind speeds.
To plan a path for dynamic soaring you need a detailed map of the different winds around the glider. So Sukkarieh is working on ways to accurately measure and predict these winds. He recently tested his autopilot on a real glider, which made detailed wind-speed estimates as it flew.
The system has on-board sensors, including an accelerometer and altimeter, which measure changes in the aircraft's velocity and altitude to work out how the winds will affect the glider. From its built-in knowledge of how wind currents move, the system was able to work out the location, speed, and direction of nearby winds to create a local wind map.
By mapping wind and thermal energy sources this way and using a path-planning program, the glider autopilot should be able to calculate the most energy-efficient routes between any two points. The system would be able to plot a path up to a few kilometers away when the wind is calm but only over a few meters when turbulent, as the winds change so quickly, says Sukkarieh.
He says that the amount of energy available to a glider is usually enough to keep it aloft for as long as it can survive the structural wear and tear. He plans to test the mapping and route-planning systems more extensively in simulations, to be followed by actual soaring experiments. "I think we have some examples from nature that mean this should be possible," says Edwards, who is not involved in Sukkarieh's research.
"We're just taking our first baby steps into doing it autonomously." Make like a hawk Hawks and vultures are masters of spiraling upwards in rising thermals. But flying around in search of a free lift is not terribly efficient so Salah Sukkarieh of the Australian Centre for Field Robotics in Sydney thinks these birds have learned to recognize visual cues for thermals, such as towering cumulus clouds surrounded by blue sky.
He's working on software that would allow a robotic glider to recognize useful cloud formations. By looking for wispy, or "smeared" clouds, the glider can find the horizontal winds that are good for dynamic soaring. At the same time, radar could measure the movement of airborne dust particles, giving an indication of wind speed and direction.
Interesting2: Globally, last month continued the warming trend of recent years, according to a monthly report by the National Oceanic and Atmospheric Administration. May 2011 was the 315th consecutive month to have a global temperature above average. The last time global temperatures dropped below the 20th-century average was in February 1985.
Of course, that doesn't mean all Earthlings felt the heat. Australia had one of its coolest Mays on record, while nearby New Zealand had its warmest May on record, according to NOAA. Arctic sea ice, which has been in decline for decades, was below average for the 120th consecutive month.
Parts of Argentina reported record lows in precipitation since 1961, while this was the wettest May on record for much of the northern Plains and northern Rockies in the United States, leading to flooding.
May 2011 saw dramatic shifts in regional temperatures in the U.S., and the average temperature, 60 degrees Fahrenheit (16 degrees Celsius), fell just below the 20th-century average by 1.0 degrees F (0.6 degrees C). NOAA's weather data extends back to 1880.
Interesting3: The UN is failing to accurately measure the global climate benefits of preserving forests. As well as providing homes for many species, trees store carbon dioxide that would otherwise warm the planet. With this in mind, the UN set up the REDD program (Reducing Emissions from Deforestation and Forest Degradation) in 2008, which will pay poorer countries to preserve their forests based on how much carbon dioxide they store.
What this fails to take into account is that forests also alter temperature in other ways. Those close to the poles are dark, and so absorb more sunlight than croplands would. But in the tropics, more water evaporates from forests than from unforested land, so they cool their surroundings.
Cool forests
To get a fuller picture, Vivek Arora of Environment Canada and the University of Victoria, British Columbia, and Alvaro Montenegro of St Francis Xavier University in Antigonish, Nova Scotia, Canada, used a computer model to estimate the overall effect of reforesting.
They used what they admit are "somewhat extreme" scenarios in which half or all of the world's croplands have been converted to forests by 2060. Foresting all or half the world's cropland reduced global temperatures in 2100 by 0.45 °C and 0.25 °C respectively.
Arora reckons that no more than 10 to 15 per cent of existing cropland is likely to be forested, so the effects will be even smaller. "The overall temperature benefits of any realistic afforestation efforts are expected to be marginal," he says.
Tropical bounty
But while the overall effect of forests is small, not all forests are equal. When Arora and Montenegro looked at the details of their results, they found that a given area of tropical forest is around three times as effective at reducing warming as the same area of high-latitude forest.
That's because tropical forests are so good at cooling their surroundings by increasing the evaporation of water. Higher latitude forests are less effective at this because they absorb so much sunlight.
Yet REDD assesses forests solely on the amount of carbon they trap, largely because measuring changes to evaporation and reflectivity is difficult. Its method assumes that estimating the carbon drawdown gives a reasonable estimate of the overall effect on temperatures, and treats low and high-latitude forests equally. The new study suggests that assumption is wrong.
"The carbon metric undervalues tropical forests," says Richard Betts of the Met Office in Exeter, UK. "We have to consider the other effects of land cover change."
Interesting4: What a difference a year makes. In February 2010, climate skeptics were crowing about apparent admissions from Phil Jones at the Climate Research Unit (CRU) in Norwich, UK, that warming trends over the period 1995 to 2009 were "not statistically significant." Skeptics including far-right media pundit Glenn Beck seized on Jones's admission, made in an interview with the BBC, to support their contention that global warming is a mirage, and had effectively come to a halt.
This week, in a follow-up to last year's announcement, Jones has said that simply adding the temperature data from 2010 to the data set has pushed the trend back into "significance". That makes it above the 95 per cent confidence interval, meaning that there is only a 1 in 20 likelihood that the warming trend is occurring by chance.
By releasing the latest analysis, Jones is attempting to illustrate the perils of plucking long-term trends from relatively short periods, such as the 15-year stretch in question.
"Next year, it could slip back into non-significance, but it shows the naivety of looking at short-term trends," Jones told New Scientist. Trends over at least 30 years are more reliable, he adds.
Cherry-picking data
"The point Phil's trying to make is that cherry-picking data to confound overall trends is not a legitimate approach," says Bob Ward of the Grantham Institute at the London School of Economics, who is a fierce critic of climate skeptics.
Jones told New Scientist that in the short time since his latest statement on the data's "significance" had been aired in the media, some skeptics had already challenged it in blogs.
But Jones insists that his latest analysis is correct because it is a combination of land and marine temperatures. "It's the combination that gives the true global picture," he says.
In 2009, Jones was plunged into the "Climategate" row over public disclosure of emails from the CRU which skeptics said showed data had been manipulated to support global warming conclusions. Subsequent internal and external inquiries cleared him and the unit of wrongdoing.
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