Hawaiian Islands weather details & Aloha paragraphs / February 9-10, 2011

Air Temperatures – The following maximum temperatures were recorded across the state of Hawaii Wednesday afternoon:

Lihue airport, Kauai –         77
Honolulu airport, Oahu –     79
Kaneohe, Oahu –               78
Molokai airport –                81
Kahului airport, Maui –       83
Kona airport –                   81
Hilo airport, Hawaii –         79

Air Temperatures ranged between these warmest and coolest spots near sea level – and on the highest mountain tops…as of 5pm Wednesday evening:

Port Allen, Kauai – 79
Lihue, Kauai – 74F

Haleakala Crater –     missing (near 10,000 feet on Maui)
Mauna Kea summit – 39 (near 14,000 feet on the Big Island)

Precipitation Totals – The following numbers represent the largest precipitation totals (inches) during the last 24 hours on each of the major islands, as of Wednesday afternoon:

0.77 Mount Waialeale, Kauai  
0.16 Oahu Forest NWR, Oahu
0.00 Molokai 
0.00 Lanai
0.00 Kahoolawe
0.01 Haiku, Maui
0.61 Kealakekua, Big Island

Marine Winds – Here’s the latest (automatically updated) weather map showing a 1037 millibar high pressure system far to our northeast, with a high pressure ridge extending southwest over the islands. Our winds will be turning southeast to south Thursday, then north later Friday.

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. This next image shows a larger view of the Pacific…giving perspective to the wider ranging cloud patterns in the Pacific Ocean. 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 14,000 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 rising just after sunset for an hour or two! Plus, during the nights and early mornings you will be able to see stars, and the sunrise 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. Here’s a tracking map covering both the eastern and central Pacific Ocean. A satellite image, which shows the entire ocean area between Hawaii and the Mexican coast…can be found here. Of course, as we know, our hurricane season ends November 30th here in the central Pacific.

 Aloha Paragraphs

Increasing showers Kauai and Oahu…then down the chain

An approaching cold front will veer out local winds to the south to southwest Thursday…and then to the north on Friday. This weather map shows a strong 1037 millibar high pressure system far to our northeast. This high pressure cell has an associated ridge of high pressure extending southwest towards our islands. Winds will swing around to the south and southwest tonight into Thursday, ahead of this cold front…now expected to arrive over Kauai early Thursday, dropping down through the island chain into Friday. Cool northerly winds will come in over the state in the wake of the cold front, becoming strong and gusty trade winds later this weekend into early next week. These trade winds may become quite blustery, necessitating small craft wind advisories for sure…and perhaps some localized wind advisories over the eastern islands as well.

Winds will be light to moderately strong…the following numbers represent the strongest gusts, along with directions Wednesday evening:

20 mph       Barking Sands, Kauai – SE
15              Kahuku, Oahu – ENE   
06              Molokai – WNW
27              Kahoolawe – SE 
06              Kahului, Maui – NE 
08              Lanai Airport – ESE        
25                South Point, Big Island – NE

We can use the following links to see what’s going on in our local skies. This large University of Washington satellite image shows lots of high and middle level clouds over the ocean to our north. Streaks of these clouds are periodically droping southward over the islands. Looking at this NOAA satellite picture, shows those streaks, plus some lower level cumulus clouds pooling to the south of the islands. We can use this looping satellite image to see lots of high and middle level clouds streaming south and eastward…over the islands at times. At the same time we see some dynamic thunderstorm cells to our northwest. Checking out this looping radar image, it shows some showers, most notably over the ocean to our south…generally heading towards Kauai and Oahu at the time of this writing.

The aforementioned cold front is heading towards Kauai…which will then reach Maui and the Big Island Thursday night into Friday. As the winds become more south and southwest…our overlying air mass will become more shower prone beginning tonight, and even more so going towards the weekend. Thursday will find showers increasing, first on the Kauai end of the island chain…then down the island chain into Friday. A mention of thunderstorms may need to be added to the forecast with time. As the trade winds return later this weekend, whatever moisture is left around then, will stream back over the windward sides into early next week. There could be some locally heavy rain falling Sunday into early next week. As we’ve seen lately, the computer models are jumping around in their outlooks, changing at times rather drastically on a daily basis…watch for more abrupt changes!

It's partly cloudy here in Kihei, Maui early Wednesday evening. As mentioned above, today was a generally fine day, although conditions will change as early as tonight, and remain off and on unsettled through the weekend, and even into the first day or two of next week. There will be showers around, some of which may become locally heavy at times. This will be especially true as the frontal cloud band comes through on Thursday and Friday…and then again towards the end of the weekend into early next week. We may see a period of strong and gusty trade winds starting up towards Sunday too, remaining blustery for several days. ~~~ I'll be back early Thursday morning with your next new weather narrative, I hope you all have a great Wednesday night until then! Aloha for now…Glenn.

Interesting: Thundersnow, also known as a winter thunderstorm or a thunder snowstorm, is a relatively rare kind of thunderstorm with snow falling as the primary precipitation instead of rain. It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone, where the precipitation consists of ice pellets rather than snow. Snowstorms that trigger lightning are rare.

Of the roughly 10,000,000 cloud-to-ground lightning flashes observed over the continental United States each year, about 0.1 percent to 0.01 percent are associated with snow, says Walter Petersen, atmospheric physicist with NASA's Marshall Space Flight Center in Huntsville, Alabama. This thundersnow happened this winter in northern Alabama and was observed first hand by sophisticated lightning mapping station in Huntsville.

There are usually four forms of thundersnow:

1. A normal thunderstorm on the leading edge of a cold front or warm front that can either form in a winter environment or one that runs into cool air and where the precipitation takes the form of snow.

2. A heavy snowstorm in the comma head of an extratropical cyclone that sustains strong vertical mixing which allows for favorable conditions for lightning and thunder to occur.

3. A lake effect or ocean effect thunderstorm which is produced by cold air passing over relatively warm water; this effect commonly produces snow squalls over the Great Lakes.

4. A cold front containing extremely cold air aloft, steepening lapse rates and causing strong vertical movement which allows for favorable conditions for lightning and thunder to occur

One unique aspect of thundersnow is that the snowfall acts as an acoustic suppressor of the thunder. The thunder from a typical thunderstorm can be heard many miles away, while the thunder from thundersnow can usually only be heard within a two to three mile radius from the lightning.

Petersen oversees a NASA-backed team that deploys to various locations around the world to collect data about precipitation, information that will be used to interpret observations from a new network of Earth-monitoring satellites. The Huntsville snowstorm was a chance to add to that information bank, without tapping the travel budget.

Early results from the impromptu campaign show that the lightning traveled for 30 to 50 miles along layers in low clouds before touching ground, a finding that has implications for safeguarding power grids, among other concerns. Scientists also found that more than 50 percent of the lightning flashes initiated off of a radio tower just east of Huntsville.

They are working to flesh out the contributing roles of snow, wind and supercold water on the development and spread of the lightning. "We've the got the ability to look at how the snowflakes originate, grow and fall, and relate that to where the lighting flashes tend to propagate through the clouds that produce the snow.

Not many events are caught like that," Petersen said. Atmospheric physicist Kevin Knupp, with the University of Alabama in Huntsville, suspects that gravity waves, which are up and down ripples in the atmosphere somewhat like waves on a beach, are the invisible hands behind thundersnow, interacting with supercold water so that electric charges can build up, leading to lightning.

Interesting2: Earth's global temperature has been rising gradually over the last decades, but the warming has not been the same everywhere. Scientists are therefore trying to pin down how the warming has affected regional climates because that is what really matters to people, and to adaptation and mitigation strategies.

Their efforts, however, had hit a roadblock because the necessary observations of the winds over the oceans were biased. Developing a new method to remove the bias, Hiroki Tokinaga and Shang-Ping Xie at the International Pacific Research Center, University of Hawaii at Manoa, found that their corrected observations show the trade winds in the tropical Atlantic have weakened and the pattern of ocean surface temperature has changed. As a result, the equatorial Amazon and the Guinea Coast are seeing more rainfall and the Sahel less.

The findings are published online in the February 6, 2011, issue of Nature Geoscience. The raw observations of winds over the ocean suggest that the winds have grown stronger during the last 60 years. The trend is, however, largely due to a change in the placement of the anemometers, the instruments measuring wind speed.

Ships are the main source of wind data over the ocean, and ships have increased in height and so has the anemometer placement. Tokinaga and Xie corrected this wind bias using wind-wave heights. The tropical Atlantic has three major ship routes along which ships provide meteorological data.

Applying their new correction technique to observations along these routes from 1950 to 2009 together with other observations, they found the trade winds in the tropical Atlantic had weakened significantly during this period. Although ocean surface temperature in the tropical Atlantic has risen, the pattern has changed and with it the climate.

The cold tongue of water that stretches out from the eastern tropical Atlantic coast has warmed more than the western part of the basin. At the same time, the weakened trade winds have resulted in less upwelling of cold water and nutrients in the eastern tropical Atlantic. These latter changes could impact marine life.

Accompanying these changes in wind and ocean temperature is a very significant increase in rainfall, not only over the ocean but also over adjacent land areas such as the equatorial coastal regions of the Amazon and the Guinea Coast. For example, the August rainfall at Ibadan, one of the largest cities in Nigeria, has increased by 79 mm/month from 1950 to 1998, which is a whopping 93% increase over the long-term average expected.

The study also suggests that the year-to-year variations of ocean temperature and rainfall have weakened during recent decades, implying fewer extreme events. Tokinaga and Xie reason that the pattern of ocean warming and trade-wind changes are caused by the asymmetric reduction in surface solar radiation due to man-produced aerosols, the reduction affecting the Northern more than the Southern Hemisphere.

If aerosol emissions decrease over the next decades, the tropical Atlantic climate may experience yet another shift as greenhouse gas forcing increases. Such a shift in the patterns of climate change (i.e., precipitation and sea level) will have important impacts on the socio-economics of regions surrounding the tropical Atlantic.

For example, "If the year-to-year variability is to recover in the future, the resulting increase in climate extremes would add burdens to an ecosystem and to a society already stressed by global warming," said Tokinaga. Historical observations of accurate winds are gravely lacking over the World's oceans.

This new robust and physically consistent set of observations by the IPRC team is valuable for improving computer models and evaluating model projections of climate change under further global warming.

Interesting3: Ten whooping cranes, the most endangered species of crane in the world, will be reintroduced in a Louisiana conservation area more than 60 years after the birds' numbers dwindled to near zero, the U.S. Interior Department said on Tuesday. "The whooping crane is an iconic species that should be returned and restored to health along the Gulf Coast," said Interior Secretary Ken Salazar.

"The reintroduction of these remarkable birds will be a milestone moment for the Gulf Coast." Whooping cranes — named for their loud, trumpeting call — are the world's most endangered species of crane and are only found in North America. The total population, once believed to have numbered more than 15,000, fell to just 15 birds in the 1940s as a result of hunting and habitat loss, according to the National Wildlife Federation.

The entire Louisiana population had been wiped out or removed by the 1950s. The surviving birds all belonged to one flock that migrated between Canada and Texas and is still the only self-sustaining wild population of whooping cranes. "That's as close to extinction as anything's ever come," said Heather Ray, director of development for Operation Migration.

Her group and others have worked to re-establish the whooping crane. There are now only about 560 birds in the wild and captivity, said Tom Hess, the Louisiana project's field manager. The cranes that will be reintroduced this month were bred at the U.S. Geological Survey's Patuxent Wildlife Research Center in Maryland and will be moved first to an enclosed pen in Louisiana's White Lake Wetlands Conservation Area, Hess said.

When the birds get used to their new surroundings, they will be released into a 1.5-acre open pen. They will be monitored, fed and encouraged to roost, said Hess, who works for the Louisiana Department of Wildlife and Fisheries. The next set of cranes should be reintroduced in October, he said. The project is expected to last about 10 years.

Interesting4: With the launch of the Nissan Leaf and Chevy Volt, it's been a big year for electric vehicles, but their batteries still have a fairly limited range without a recharge. For a car running on today's lithium-ion batteries to match the range provided by a tank of gasoline, you'd need a lot more batteries, which would weigh down the car and take up too much space.

But what if you could take away one of the electrodes in a battery and replace it with air? Researchers estimate that a lithium-air battery could hold 5 to 10 times as much energy as a lithium-ion battery of the same weight and double the amount for the same volume. In theory, the energy density could be comparable to that of gasoline.

"No other battery has that kind of energy density, so far as we know," says Ming Au, principal scientist at Savannah River National Laboratory (SRNL), in Aiken, S.C. Au was one of several scientists who reported new research into rechargeable lithium-air batteries during the fall meeting of the Materials Research Society, in Boston.

In such a battery, the anode is made of lithium. The cathode is oxygen, drawn from the surrounding air. As the lithium oxidizes, it releases energy. Pumping electricity into the device reverses the process, expelling the oxygen and leaving pure lithium.