Hawaiian Islands weather details & Aloha paragraphs

A surface trough of low pressure is moving across the state of Hawaii, and will be to the west of Kauai Wednesday. The latest weather map shows a 1036 millibar high pressure system far to the northeast, and a trough of low pressure moving westward across the islands. This migration of the trough across Hawaii, has caused lighter winds from the east-southeast and southeast. This wind direction has carried thick volcanic haze up the chain from the Big Island to Maui and beyond. We’ll find trade winds returning later Wednesday, into the upcoming weekend…helping to carry the vog away later in the week.

The trough will help to make our atmosphere more shower prone, as well as warm and muggy. As this trough moves over the state, our overlying atmosphere has become unstable, and more shower prone in the process. Therefore, we can look for a few more showers through Wednesday, some of which will be locally heavy…with the chance of a thunderstorm here and there. As the trade winds return later Wednesday into Thursday, we’ll see most of the shower activity occurring along the windward coasts and slopes.

It’s Tuesday evening as I begin updating this last section of today’s narrative. The long lasting low pressure system, which was hanging out to the NE of the islands, has opened up into a more or less northeast to southwest oriented trough of low pressure. This elongated trough had passed over the Big Island, Maui,and Oahu…and almost over Kauai early Tuesday evening. The daytime heating of the islands caused clouds to form during the day, with active showers locally. The heaviest showers broke out on the Big Island and also the north shore of Oahu…where localized flooding conditions occurred. ~~~ Wednesday will find the trough located to the west of Kauai. The atmosphere over the state in the wake of the trough’s passage will remain warm, moist and locally showery. The trade winds will fill in behind the trough, and gain strength through the remainder of the week into next week. These blustery trade winds will carry showers in our direction, arriving most frequently, and generously, along the windward coasts and slopes.

The weekend weather outlook is still a bit sketchy, with some of the computer forecast models bringing in an area of clouds and showers. It’s still too early to reel this wet forecast into the boat…hook, line, and sinker. I recommend that we don’t get too overly serious about this showery episode just yet, giving the models another day or so, to clarify their weather solution for the weekend time frame. ~~~ Tuesday morning started off just fine, with relatively clear skies. As the day wore on however, the southeast winds brought copious amounts of thick volcanic haze up from the Big Island, onward to Maui and on to Oahu. The volcanic emissions were enough of a problem on the Big Island, that Harry Kim, the mayor there, initiated evacuations from some areas, due to the hazardous air qualities! ~~~ I’ll be back again very early Wednesday morning with your next new weather narrative. I hope you have a great Tuesday night wherever you happen to be spending it! Aloha for now…Glenn. 

Interesting: The world’s largest tidal turbine, weighing 1000 tons, has been installed in Northern Ireland’s Strangford Lough. The tidal turbine is rated at 1.2 megawatts, which is enough to power a thousand local homes. It was built by Marine Current Turbines, and it will be the first commercial tidal turbine to produce energy, when it begins operation later this year.  The turbine has twin rotors measuring 16 meters in diameter. The rotors will operate for up to 18-20 hours per day to produce enough clean, green electricity.  The turbine will be positioned 400 meters off of shoreline in Strangford Lough, which is know for its fast tidal current, and protection from severe weather.  The rotors on the SeaGen turbine turn slowly: about 10 to 20 revolutions per minute. A ship’s propellers, by comparison, typically run 10 times as fast. The risk of impact from SeaGen rotor blades is small, because the marine creatures that swim in strong currents tend to be agile, and can avoid slow-moving underwater obstructions.

Interesting4: With the start of spring comes the start of the tornado season in the USA and yet 2008 has already seen an unusually high number of tornadoes. The National Weather Service (NWS) keeps a count of all tornadoes via Local Storm Reports (LSR’s) collated from its various offices across the country. Preliminary reports are often over estimated as offices receive several reports for the same tornado. However despite this, the number of tornadoes reported in the first three months of this year still far exceeds the number in previous years. From January to March 2008 up to 516 preliminary tornado reports were noted, this compares to 330 in the same period in 2007 and is said to be almost two and a half times the 10-year average. The increased activity has been attributed to the current La Niña and though this is expected to weaken over the spring, the season has only just officially begun. It is usually during the spring months that tornado activity is at its highest with conditions ripe for their development. A large portion of these tornadoes develop across the central US in an area referred to as “Tornado Alley”. An outbreak of severe storms is expected to develop across central US later this week which could spawn some significant tornadoes.