Hawaiian Islands Weather details & Aloha paragraphs / December 11-12, 2011

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

Lihue, Kauai –                   77
Honolulu airport, Oahu –   82  (record high temperature for the date…88F degrees – 1995)
Kaneohe, Oahu –               77
Molokai airport –                78
Kahului airport, Maui          81 
Kona airport                        82
Hilo airport, Hawaii –          76

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

Barking Sands, Kauai  – 81
Kahului, Maui – 72

Haleakala Crater – M (near 10,000 feet on Maui)
Mauna Kea –         M (near 13,800 feet on the Big Island)

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. 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. Here's the Haleakala Crater webcam on Maui…which is working only sometimes lately.

 Aloha Paragraphs

Locally windy, windward showers, leeward
at times…chance of a thunderstorm – cool
Flash flood watch statewide

As this weather map shows, we find a large 1034 millibar high pressure system located to the northeast of the Hawaiian Islands Sunday evening. There's also a trough of low pressure located over the east side of the state.  This pressure configuration keeps moderately strong trade winds blowing across our latitudes of the north central Pacific, rather strong and gusty at times, becoming gradually a little lighter into Monday…especially over the Big Island and Maui County.

The following numbers represent the strongest wind gusts (mph), along with directions Sunday evening:

35                 Lihue, Kauai – NE
33                 Honolulu, Oahu – NW
40                 Molokai – NE
38                 Kahoolawe – NNE
31                 Kaupo Gap, Maui – NNE
52                    Lanai – NE
35                 Waikoloa, Big Island – NE

We can use the following links to see what’s going on in our area of the north central Pacific Ocean Sunday evening. Looking at this NOAA satellite picture we find that a large area of high and middle level cloudiness over and around the island chain, everywhere except Kauai at the time of this writing. We can use this looping satellite image to see this large area of clouds over the ocean to the south through east of the islands…with thunderstorms flaring up not far away from the islands to our north. Checking out this looping radar image we see showers over the ocean, most of which are in the light to moderately heavy category, although there are patches of heavy rain mixed in as well…moving over the islands at times locally. 

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

3.80               Kilohana, Kauai
1.52               Moanalua RG, Oahu
0.57               Molokai
0.00               Lanai
0.01               Kahoolawe
4.08               Puu Kukui, Maui
7.56                 Laupahoehoe, Big Island

Sunset Commentary:  The trade winds continue to blow steadily, and in fact remain strong and gusty in nature to the west of a trough of low pressure over Maui County. A high pressure system far to our northeast will keep these active winds blowing. This in turn has made our marine coastal and channel waters rough and choppy…necessitating small craft wind advisories everywhere except around the Big Island. These gusty winds are expected remain quite active through into the new week ahead…at least over Kauai and Oahu.

Rainfall will remain an issue…most notably along our windward sides where it will be wet. The trade winds are strong enough that showers will spill over into the leeward sides on the smaller islands at times too. These showers will remain more active than normal, continuing as we push into the new work week ahead. We can see on this satellite image, to see all the clouds that are over our area.. There will be colder air over the state too, which will enhance these showers. If we look closely, we can see several thunderstorms firing over the ocean, and close to some parts of the islands too.  Here's a looping radar image so we can keep a close eye on all these abundant showers.

This past Friday evening I took the drive over to Kahului after work to see a new film. This one was called Tower Heist, starring Ben Stiller, Eddie Murphy, Alan Alda, Matthew Broderick, Tea Leoni…among many others. The synopsis: when a billionaire steals their retirement money, the workers at a luxury condominium come up with a plan to even the score. The critics are giving this film a B- grade, while the viewers are upping it slightly to a B rating. As is almost always the case, I liked the film better than I thought I was going to. It was sort of clever in a way, and actually was kind of fun to watch. It took place in some big city here in the United States, I think New York, which made it exciting. Lets see, I think I'll go along with the pack here again, and give it a B grade. It wasn't a film that was great by any means, although as it turned out, it was worth sitting in the theater for. Here's a trailer for this film, just in case you have an interest in taking a quick peek.

Here in Kula, Maui at around 5pm Sunday evening, its partly to mostly cloudy…with an air temperature of 63.7F degrees. Our inclement weather conditions will continue, with locally gusty winds, cloudy skies, and locally heavy showers falling at times. The cold air aloft continues to make the overlying atmosphere unstable and shower prone. We continue to have an unusual flash flood watch across the entire state, which suggests that heavy rain will fall locally here and there. The cold air aloft has also prompted a winter weather advisory over the summits on the Big Island, where snow will be falling at times. The brunt of this wet and windy weather will remain in place through tonight. As we move into Monday, and the following few days, there could continue to see some localized heavier showers. The threat of localized thunderstorms should fade quite a bit starting Monday however. I would suggest driving very carefully, as roads will be wet and slick! ~~~ Sunday here in the upcountry area of Maui, it was cloudy and cool, along with off and on passing showers, generally light. Much of the state from Oahu down through the Big Island experienced similar conditions, although with more pronounced rainfall along our windward sides. I'll be back early Monday morning with your next new weather narrative, I hope you have a great Sunday night until then! Aloha for now…Glenn.

Extra: youtube video of hurricane force winds yesterday on the Big Island!

Extra: Snow atop Mauna Kea on the Big Island Sunday – live webcam

Interesting:  Scientists have used satellite data from NASA-built Landsat missions to confirm that more than 20 years of warming temperatures in northern Quebec, Canada, have resulted in an increase in the amount and extent of shrubs and grasses. "For the first time, we've been able to map this change in detail, and it's because of the spatial resolution and length-of-record that you can get with Landsat," says Jeff Masek, the program's project scientist.

He's based at NASA's Goddard Space Flight Center in Greenbelt, Md. Masek and his co-authors will present their study at the American Geophysical Meeting in San Francisco on Dec. 9. The study, focusing on Quebec, is one of the first to present a detailed view of how warmer temperatures are influencing plant distribution and density in northern areas of North America.

"Unlike the decline of sea ice, which is a dramatic effect that we're seeing as a result of global warming, the changes in vegetation have been subtle," Masek says. Computer models predict the northward expansion of vegetation due to warmer temperatures.

"They predict a dramatic change over the next 100 years, and people have been wondering why we weren't seeing these changes already, Masek says. The difference between the computer predictions and real-life vegetation may have to do with all the other factors that come into play with plants, like the availability of water and sunlight; the type of terrain; competition from other plants for soil, resources and space; and plant predators like caribou.

"The warm temperatures are only part of the equation," says Doug Morton, the Principal Investigator of the study and a researcher at NASA Goddard. Scientists track vegetation with satellites by measuring the 'greenness' of a study area.

Morton says previous studies used yearly compilations, making it difficult to determine if the increase in 'greenness' was due to expansion of vegetation cover or if what scientists were seeing was instead just the effect of a longer growing season.

For this study, the scientists focused only on 'greenness' measurements during the peak summer growing seasons from 1986 to 2010. By using Landsat's higher, ~98 foot resolution and viewing the same area at the same time for 23 years, Masek and his colleagues were able to track the areas as they continued to show more 'greenness' over the years.

"It makes sense," Masek says. "This is how shrub encroaching occurs. They increase in size, they increase in density, and then they move northward." In contrast to the expansion of shrubs, the scientists found little evidence for 'greenness' trends in forested areas, suggesting that forest response to recent warming may be occurring more slowly.

Masek adds that it shows how getting the big picture of warming's effect on forests will rely on continued observations from new U.S. missions that extend and enhance these data records.

Interesting2:  A second hurricane-strength storm is heading for the UK and this time the entire country looks set to suffer. Forecasters say the next severe storm is now brewing in the North Atlantic and will bring with it cold air, snow and sleet as well as hurricane-strength winds from Monday evening. They say next week's massive storm will affect the whole of the UK and will last through the whole of Tuesday and into Wednesday.

Weather experts say they cannot officially classify the storms as hurricanes because the severe weather systems have a cold core instead of a warm core, but the wind speeds are the same and they still carry the same destructive power. Weather expert Tim Ballisty, a meteorologist at weather.com, said: "There are two main computer models that we use to forecast the weather and both are showing an intense area of low pressure that will swing in across the North Atlantic on Monday, last all day Tuesday and into Wednesday."

Tim described how the huge weather system will "stall out" over the UK and the forecasts show the area of low pressure, that brings severe winds and rain, will deepen and intensify across the whole of the UK and across to the west coast of France. He explained: "What is interesting about this next storm is that the huge weather system that slammed into Scotland on Thursday was very constrained, its damage was limited to Scotland.

"However, next week's storm looks likely to cover the whole of the UK, it is tremendously wide and has a much broader scope to it. "The winds may not be nudging 150mph again but it will certainly produce the same destructive power as Thursday's storm." Tim said the forecasts showed the massive storm will arrive late on Monday with heavy rain across most parts of the country, followed by a very cold air mass, which will trigger sleet and snow.

The hurricane-force winds of at least 74mph will last through the whole of Tuesday and into Wednesday. And Jonathan Powell of Positive Weather Solutions, who accurately warned of the huge scale of Thursday's storm earlier in the week, said they also had picked up the aggressive new storm in the Atlantic.

He told ClickGreen: “This storm will affect the entire nation, Monday will be a complete wash-out and whereas Scotland took the last storm on the chin – this will hit the whole of the country square-on.”

Tim Ballisty explained that while the UK was in the icy grip of the Big Freeze this time last year, this year a change in the upper atmosphere meant the country would be prone to more wild weather and Atlantic storms.

“In 2011, there was what was known as the 'Greenland Block' that virtually created a traffic jam in the atmosphere – the Arctic air that normally progresses from West to East was forced to plunged Southward and created the Big Freeze across much of the northern hemisphere, including the East Coast of the US and much of Europe.

“However this year, there is no 'Greenland Block' so these weather system can freely pass from West to East unobstructed.
“These storms are all part of the seasonal change and look very likely to continue.”

The UK Met Office this afternoon issued a Severe Weather Warning for the South and South West of the UK for Monday and Tuesday, advising of the risk of heavy winds. The yellow alert is in place between 6pm on Monday evening to 6pm on Tuesday evening.

The advisory states the South and West are at the “greatest risk of very windy weather on Monday evening and during Tuesday which could lead to disruption.

“At this stage there is a good deal of uncertainty and the public are advised to monitor forecasts over the weekend to keep up to date with this warning. Hurricane-strength winds of more than 75mph are being forecast by Jonathan Powell at Positive Weather Solutions, who warns overnight Monday will be a critical time.

He predicts the massive incoming storm will not pack the same destructive punch as the weather system that crashed through Scotland on Thursday as some of its power will be lost as it crosses Ireland.  However, the huge low area is far wider and is expected to stay across most parts of the UK until Wednesday.