Hawaiian Islands weather details & Aloha paragraphs / June 1-2, 2011

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

Lihue, Kauai –                    81 
Honolulu airport, Oahu –    86 (record high Wednesday: 91 – 1996)   
Kaneohe, Oahu –                80
Molokai airport –                 83
Kahului airport, Maui –          86  (record high Wednesday: 92 – 1969)   
Kona airport                       84  
Hilo airport, Hawaii –           80

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

Barking Sands, Kauai – 84
Hilo, Hawaii – 76

Haleakala Crater –     46 (near 10,000 feet on Maui)
Mauna Kea summit – 28 (over 13,500 feet on the Big Island)

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

1.84     Mount Waialeale, Kauai
1.02     Oahu Forest NWR, Oahu
0.02     Molokai
0.00     Lanai
0.00     Kahoolawe
1.74     West Wailuaiki, Maui
0.76     Pahoa, Big Island

Marine Winds – Here’s the latest (automatically updated) weather map showing a 1033 millibar high pressure system…to the northeast of our islands. Our local winds will remain on the strong and gusty side Thursday and 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. 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. 

 Aloha Paragraphs

Trade winds – localized heavy showers…a few thunderstorms

Our local winds will remain active from the trade wind direction…remaining on the strong side of the wind spectrum through Friday.  Glancing at this weather map, we find a 1033 millibar high pressure system located to our northeast…which will remain the source of our trades. These trade winds will remain active, with the small craft wind advisories covering those windiest coasts and channels from south of Oahu, Maui County to the Big Island. The trade winds will begin relaxing some later Friday…then more so later this coming weekend into early next week. There have been some discussions about these trade winds becoming very light, and perhaps even veering to the east-southeast, or southeast. This will triggered by a very late season cold front moves by to our north…pushing our trade wind producing high pressure ridge right down close to the islands with time.

Our trade winds will continue to blow quite strongly…the following numbers represent the strongest gusts, along with directions Wednesday evening:

31                 Port Allen, Kauai – NE 
30                 Honolulu, Oahu – NE 
31                 Molokai – NE
33                 Kahoolawe – E   
35                 Lipoa, Maui – NE 
05                 Lanai – NE  
40                    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 Wednesday night.  Looking at this NOAA satellite picture we see that most of the clouds in our area are located over the ocean, although there are some localized heavy showers still falling over the Big Island, although the other islands have cleared off pretty well at the time of this writing.  We can use this looping satellite image to see areas of high and middle level clouds moving by to our south and then veering up towards the southeast and east. We can see the on and off brighter white clouds that form and then dissipate away. Checking out this looping radar image we see showers being carried towards the islands from the east, although not very many at the time of this writing.

Sunset Commentary:  I've been using the word unusual so much the last couple of days, and I may not be quite done! Thunderstorms on the 1st of June is rare enough, but to have the trade winds gusting up to 40 mph at the same time, very unusual indeed. A friend of mine at the NWS forecast office in Honolulu was throwing around the word "thundertrades". This year has been filled with weather that just doesn't fit into the normal realms it seems, with more thunderstorms than I can ever remembe…in the 36 years that I've lived here in the islands! Thunderstorms just so happen to be one of my absolute favorite weather types, so I'm delighted! 

It snowed atop the Mauna Kea summit today on the Big Island, which isn't common by any means. The upper level low pressure system that continues to edge more or less in our direction, has lots of cold air associated with it. This cold air up high doesn't influence our surface temperatures, but certainly makes our overlying atmosphere unstable….unstable enough to prompt the thunderstorms, and that snow up high. The Haleakala Crater on Maui is well below this cold air, so it didn't see a single white flake falling. This cold air isn't done with us yet, and may keep more unusual weather happening for a few more days.

As I was mentioning this morning, this will be a hit and miss situation, with clouds and showers mixing it up with clear periods too. Each of the islands had some amount of heavy showers today, with thunderstorms or at least towering cumulus clouds stacked-up over each island as well. I figure we can expect more of this Thursday, and perhaps Friday and Saturday locally too. As we move into the weekend, and even early next week, we'll have another unusual occurrence, which will be the slacking-off of our local trade winds. This will put us into a convective weather pattern, with muggy weather and the continued chance of afternoon heavy showers…especially over and around the leeward slopes during the afternoons then. 

Here in Kihei, Maui at around 540pm, skies were partly cloudy, with a mix of high and low level clouds. There was a big towering cumulus cloud over the Haleakala Crater most of the day, although I didn't see any showers down here in the lowlands of Kihei. I'm about to head back upcountry to Kula now, although am already greatly looking forward to getting back online early Thursday morning, when I'll whip out yet another new weather narrative for you then. I hope you have a great Wednesday night! Aloha for now…Glenn.

Interesting: Scientists from the U.S., U.K. and Australia have used ice-penetrating radar to create the first high- resolution topographic map of one of the last uncharted regions of Earth, the Aurora Sub-glacial Basin, an immense ice-buried lowland in East Antarctica larger than Texas. The map reveals some of the largest fjords or ice cut channels on Earth, providing important insights into the history of ice in Antarctica.

The data will also help computer modelers improve their simulations of the past and future Antarctic ice sheet and its potential impact on global sea level.

"We knew almost nothing about what was going on, or could go on, under this part of the ice sheet and now we've opened it up and made it real," said Duncan Young, research scientist at The University of Texas at Austin's Institute for Geophysics and lead author on the study, which appears in the journal Nature.

Interesting2: A team of scientists from the University of Sheffield and Bangor University have used a computer climate model to study how freshwater entering the oceans at the end of the penultimate Ice Age 140,000 years ago affected the parts of the ocean currents that control climate. A paper based on the research, co-authored by Professor Grant Bigg, Head of the University of Sheffield's Department of Geography, his PhD student Clare Green, and Dr Mattias Green, a Senior Research fellow at Bangor University's School of Ocean Sciences, is currently featured as an Editor's Highlight in the journal, Paleoceanography.

The study is the first of this kind for the time period. The research found that freshwater entering the ocean from melting ice sheets can weaken the climate controlling part of the large-scale ocean circulation, with dramatic climate change as a consequence. During the period of the study, the experts noted that the global temperature dropped by up to two degrees over a few centuries, but changes were not uniform over the planet, and it took a long time for the climate to recover after the ice sheets had melted completely.

The team argues that it is not only the volume of freshwater being released from the melting ice sheet which is important but also the state of the freshwater: icebergs act to reduce the ocean circulation less than melt water, but the effects of icebergs last for longer periods of time. The effect is similar to the difference between adding very cold water to a drink or adding an ice cube or two.

The study also shows that at the end of the more recent Ice Age 20,000 years ago, the ocean circulation was more sensitive to ice sheet collapses than during the earlier period. Professor Grant Bigg, Head of the University of Sheffield's Department of Geography, said: "An important component of the work is that it shows that the impact of freshwater releases from past, or future, ice masses depends critically on the form — whether fresh water or icebergs — and the location of the release.

"The Arctic has been surrounded by extensive glaciations several times in the past and this study has shown that large-scale changes in such Arctic ice sheets could affect the climate in places far from the release site. Our work also suggests that the Pacific Ocean may have been more sensitive to major changes in past glaciations than previously realized. We plan to investigate this possibility more in the future."

Dr Mattias Green from Bangor University, added: "With melt water- similar to adding water to your drink, the water spreads out quickly and has an immediate effect, but it is also absorbed quickly into the rest of the ocean. In a similar way to your ice cube, the icebergs drift along and melt more slowly.

This means the immediate impact is weaker, but they are there for a longer time and distribute the water over a larger area. "Our results lead us to conclude that a future ice sheet collapse, that might happen in Antarctica or Greenland, would have climatic consequences, but the exact impact needs to be evaluated in each case."

Interesting3: Colorado State University forecasters predicted there would be 16 tropical storms during the Atlantic hurricane season that began on Wednesday, with nine growing into hurricanes. The CSU team predicted five of those would become "major" hurricanes of Category 3 or stronger on the Saffir-Simpson intensity scale, with winds of 111 miles per hour or more. The forecast for the six-month hurricane season was unchanged from the CSU team's April forecast, but still anticipates a busier than average season.

"We continue to anticipate an above-average probability of United States and Caribbean major hurricane landfall," said William Gray, who pioneered CSU's seasonal forecasts. There was a 72 percent chance that a major hurricane would hit somewhere on the U.S. coast this year, based on historical averages, the CSU forecasters said.

Interesting4: Hurricane season officially began Wednesday, with forecasters saying it's likely to be an above-average season. Colorado State University's Tropical Meteorology Project predicts many as five major hurricanes could form over the Atlantic Ocean. The university predicts 16 named storms and a total of nine hurricanes. The National Oceanic and Atmospheric Administration (NOAA) outlook is for 12 to 18 named storms, six to 10 hurricanes and three to six major hurricanes.

Hurricanes are categorized by the Saffir-Simpson Hurricane Wind Scale, a 1-to-5 categorization based on the storm's intensity. Storms are classified as Category 1 hurricanes when wind speeds top 74 mph. The scale goes up to Category 5, with sustained wind speeds greater than 155 mph. A named storm has winds of 39 mph or higher, and major hurricanes are those in categories 3, 4 or 5 — with winds of 111 mph or higher.

This could be an above-average season, said NOAA's Jane Lubchenco, a marine ecologist and environmental scientist. "The United States was fortunate last year. Winds steered most of the season's tropical storms and all hurricanes away from our coastlines," Lubchenco said. "However, we can't count on luck to get us through this season. We need to be prepared, especially with this above-normal outlook."

NOAA said among the factors leading to the above-average season is warm Atlantic water. Sea surface temperatures in areas where storms are likely to form are up 2 degrees Fahrenheit from average temperatures, NOAA said. The Atlantic hurricane season begins June 1 and ends November 30.

Interesting5: The hurricane season officially begins Wednesday, and it apparently won't be an easy one for forecasters. But one expert said typically hurricane-free cities may be overdue for a major storm. This year, the National Hurricane Center is expecting the storm season to be busier than usual: up to 18 named tropical storms, with three to six of them major hurricanes.

Last year was the third-most active season on record, with 19 named storms, 12 of which became hurricanes. But only one gave the U.S. any problems.

The Weather Channel's Rick Knabb, a hurricane expert, reported that five U.S. cities are long overdue for hurricanes and are just as vulnerable as cities in the South: Honolulu; New York; San Diego; Savannah, Ga.; and Tampa, Fla.

Below are summaries of those cities' histories with hurricanes, listed in order of the most recent storms:

* Tampa A hurricane estimated to have the strength of a Category 2 storm damaged parts of the Tampa Bay area in 1921, Knabb reports. The bay surged by about 10 feet because of the storm.

* Savannah While hurricanes came ashore and near the city in 1911, 1940, 1947 and 1979, the last major one to hit it was in 1893, killing between 1,000 and 2,000 people, Knabb reports.

* New York The area of the city between the Coney Island neighborhood of Brooklyn and John F. Kennedy International Airport was slammed by a Category 1 storm in August 1893, Knabb reports. If a similarly sized storm went further west than the eastern edges of the city, Knabb estimates the waters of New York Harbor would surge by about 30 feet.

* San Diego The sole hurricane found to have hit California happened on Oct. 2, 1858, when powerful winds damaged large swaths of property, Knabb reports.

* Honolulu Hawaii's capital hasn't had any recorded hits by a hurricane, but Knabb reports it's had several close calls, most recently by Hurricane Iniki in 1992, which struck Kauai, about 100 miles west of the capital.

This year, both the El Nino and La Nina effects are relatively quiet, making forecasting harder. They are warming and cooling trends that can either rev up hurricanes or suppress them.

Both of them are expected to be neutral this year. That could make it more difficult to say how bad the 2011 hurricane season will be.

The last time temperatures were neutral was 2005, when hurricanes Katrina and Rita slammed into the Gulf Coast.