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Cyclone: So many meanings

Posted by wwadmin on Mon, 24/12/2012 - 13:45

When someone talks about a “cyclone”, they can mean several different things. Some of it depends on where in the world they are from. It can also depend on whether they are using the general term or a talking specifically about one particular type of storm.

First of all, let’s start with the most general definition. A cyclone is simply an area of low pressure. The lower pressure is caused by the fact that air is rotating around the low whilst it spins inward. Like water does when you pop the drain on your sink.

These are your general, every day “lows”. These are shown as a big “L” on a weather map. These are important factors in creating our daily weather. This indicates lifting air, which means an unstable atmosphere which in turn, can lead to clouds and precipitation. Air rotates around a cyclone in a clockwise direction here in the Southern Hemisphere.

Those cyclones can lead to other cyclones. Tornadoes are cyclones. In the middle part of the US, it is very common to use the two terms interchangeably. However, whilst all tornadoes are cyclones, not all cyclones are tornadoes.

A cyclone can also be a big storm. Like Tropical Cyclone Evan. But again, whilst these types of storms are all cyclones in that they are areas of low pressure, they don’t all qualify as “Tropical Cyclones” in the way the term is used in Australia and the South Pacific. If the winds do not exceed 62km/h, then it is simply called a Tropical Disturbance, Tropical Depression, or Tropical Low. When the winds are at 63km/h or greater, then it is called a Category 1 Tropical Cyclone.

That same type of system in US waters of the Northeast Pacific or North Atlantic is called a Tropical Storm, but it’s still a cyclone because it is still an area of low pressure.

After the winds exceed 118 km/h, it starts to get confusing. At that point, the storm is on the higher end of the Category 1 Hurricane classification according to the US. But in the northwestern Pacific it is called a Typhoon. In the northern Indian Ocean it could be called a Very Severe Cyclonic Storm. In the southwest Indian Ocean it would be called a Tropical Cyclone and in Australia and the south Pacific it would be a Category 3 Tropical Cyclone.

There are so many definitions of the term “Cyclone” and so many ways attempts have been made to classify cyclones, it’s enough to make you dizzy.

By Howard Joseph, WeatherWatch.co.nz

Posted on December 28, 2012 at 9:47 PM

Amazing new views of Earth at night

Posted by wwadmin on Wed, 19/12/2012 - 11:00

How does the globe look when the sun goes down? Earlier this month, scientists unveiled unprecedented snapshots of Earth at night. Global composite images, constructed from cloud-free nighttime images from the new NOAA-NASA Suomi NPP satellite, were showcased at the American Geophysical Union’s annual meeting in San Francisco. The images reveal the glow of human and natural phenomena across the entire Earth in more detail than ever before.

Many of today’s satellites are equipped to look at Earth during the day, when they can observe relatively bright objects ─ especially those illuminated by the sun. But the “day-night band” of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the Suomi NPP satellite is equipped with advanced technology that extends the view of Earth's atmosphere and surface into the nighttime hours.

In the new images, the first things to capture the eye are the planet’s cities

“Nothing tells us more about the spread of humans across the Earth than city lights,” said NOAA’s Chris Elvidge. Elvidge has studied nighttime lights data since 1992, with satellite images far less precise than the news ones. “Even after 20 years, I'm always amazed at what city light images show us about human activity.”

Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual picture elements or pixels. The day-night band goes further, however, to ensure that each pixel collects the right amount of light. If a pixel is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal will be strongly amplified.

“NOAA’s National Weather Service is continuing to explore the use of the day-night band,” said Mitch Goldberg, program scientist for NOAA’s Joint Polar Satellite System, JPSS. “The very high resolution from VIIRS data will take forecasting weather events at night to a much higher level.”

For example, the VIIRS day-night band watched the recent storm Sandy, illuminated by moonlight, as it made landfall over New Jersey on the evening of Oct. 29. Night time images showed the widespread power outages that left millions in darkness in the wake of the tremendous storm. By revealing such impacts of disaster on human life, the Suomi NPP imagery makes for a more complete view of storms like Sandy, which were previously observed primarily with infrared bands.

“For all the reasons that we need to see the Earth during the day, we also need to see the Earth at night,” says Steve Miller, a researcher in NOAA’s Cooperative Institute for Research in the Atmosphere at Colorado State University. “Unlike us humans, the Earth never sleeps.”

Other phenomena observable with the day-night band become evident only at night. City lights reveal the human footprint on Earth in striking detail, which researchers have used to model the spatial distribution of economic activity. Carbon dioxide emissions from natural gas flares can be measured quantitatively. Fishing boats offshore in the Yellow and East China seas are seen to orient along political boundaries.

VIIRS is not the first instrument to look at nighttime lights. The U.S. Defense Meteorological Satellite Program has made observations with low-light sensors for 40 years. NOAA’s well-known nighttime lights images derive from those satellite data. The new VIIRS day-night band can better detect and resolve Earth's night lights; it is sensitive enough to detect lights as small as a single street lamp and even the nocturnal glow produced by the Earth’s own atmosphere.

You can see all the images athttp://earthobservatory.nasa.gov/NightLights....

All images/ NASA


Posted on December 19, 2012 at 9:29 PM

IMAGE- Saturn's stunning storm

Incredible photos of storms on Saturn were sent back to earth this week from NASA’s Cassini Spacecraft.

The images show the spectacular vortex photographed on Tuesday from a distance of about 400,000 kilometres above Saturn.

The Cassini spacecraft has been traveling the Saturnian system in a set of tilted, orbits that give mission scientists a vertigo-inducing view of Saturn's polar regions. This perspective has yielded images of roiling storm clouds and the swirling vortex at the centre of Saturn's famed north polar hexagon.

NASA says this is not the first time a storm like this has been photographed by Cassini. In 2008, a similar storm was captured over the south pole.

The Cassini mission to Saturn began with its launch into space on 15 October 1997, arriving at Saturn for the first time nearly 7 years later on 30 June 2004.

-All images/ NASA/JPL

-By NASA/JPL and WeatherWatch.co.nz

Posted on December 02, 2012 at 9:30 PM

How The Weather Company survived a 1,000% traffic spike during Hurricane Sandy

How The Weather Company survived a 1,000% traffic spike during Hurricane Sandy

Maintaining service during a massive and destructive storm can be difficult. But The Weather Company, a source for weather forecasts and data, found itself in the middle of its own storm during Hurricane Sandy, as panicked people pushed its website traffic levels literally 1,000 percent higher than normal.

Sandy’s timing couldn’t have been worse, as the Weather Company is in the early stages of a massive transformation, transitioning from 13 global data centers to managed hosting in Amazon’s cloud.

Perhaps it was lucky number 13, however, because in spite of a Boston data center being caught in the storm, the company’s 100-strong technical team maintained the site, apps, and services at a 99% uptime rating throughout the storm.

I talked to the Weather Company’s chief information officer, Bryson Koehler, about how they did it.

“We saw double the traffic that we’ve ever seen before on our digital platforms,” Koehler told me. “We had to handle 10X the traffic we’ve ever had before.”

The Weather Company delivers news on basically any medium you can imagine: the original TV show, smartphone apps, tablet apps, live streaming video online, print, radio, and APIs for partners all over the globe. On a typical day, the company serves the equivalent of about 40 million pageviews on its digital platforms, and it has previously seen service interruptions when the number approached only 120-140 million.

But on Monday, the company was serving 110 gigabytes of data per second, almost without a hiccup, not counting the livestreams — 170 thousand simultaneous streams of live video, pushed out over the Internet.

The question is: how?

While the Amazon Web Services integration is still mainly in the future, The Weather Company did have several hundred instances running at 100% capacity, Koehler said, telling me that the scalability was “exactly what you would expect,” as was the cost efficiency.

But the company had significant help from three additional critical partners.

“We relied very heavily on three partners that helped us deal with the sudden surge: Verizon, Akamai, Google were great throughout the storm.”

Akamai, of course, accelerates and distributes site load. Verizon manages some of the company’s data centers and much of its networking infrastructure, adding gigabytes of capacity literally in real time during the course of the hurricane. Google manages the livestreams, as The Weather Company delivers live video via a partnership with YouTube.

But the 13 data centers were key to the service’s resilience. Like any large organization that has been built over time and acquired other companies, Koehler said, there’s a mix of technologies.

“You end up with a good bunch of technologies that come together, but for the most part, we run Linux servers, Apache for web serving, Tomcat for our app server, and VMware for virtualization. MySQL is our core weather database.”

More than the technology, though, Koehler said it’s about the team. The Weather Company put together a 100-person hurricane team: technicians, system administrators, and networking specialists. “We were very prepared,” he said.

Read more athttp://venturebeat.com/2012/11/02/how-the-weather-company-survived-...

Posted on November 09, 2012 at 3:29 PM

Ridin' the golf cart railway

Paul Charman gives the thumbs up to the distinctly eccentric vehicles plying the Stratford-Taumarunui tourist railway.

Forgotten World Adventures operations manager Van Watson gives passengers a driving tutorial before they set out sightseeing.

Backyard tinkerers have long fitted railway wheels to an assortment of maverick machines designed to run either on tarmac or on rail.

Back in the 1930s, the general manager of New Zealand Railways had his own "inspection railcar", a car adapted to drive along the rails.

And, in a famous 1987 episode of MacGyver, our hero escapes from trigger-happy Latin American guerrillas by stripping down a jeep to run along jungle railway tracks.

No problem for MacGyver; all he needed was a Swiss army knife, some duct tape and a spare hour.

But Waikato entrepreneur Ian Balme found the job slightly more taxing when he decided to run tourists along the old Stratford to Okahukura Railway Line.

Balme's company, Forgotten World Adventures, began operations this month, using half a dozen "rail carts", actually golf carts, which can be converted into railway vehicles within about a minute.

The machines run daily on a rail line built from 1901 until 1933, then mothballed in 2009.

Several versions of the ride are attracting adventure tourists from far and wide.

The company's primo ride is a leisurely two-day junket over the full 142km of line, broken in the middle with an overnight stay at the Whangamomona Hotel.

Having taken this "Ultimate Tour" at Labour Weekend, I can attest that the converted golf carts run on the historic track with ease, actually crossing 24 tunnels (the longest more than 1km), numerous bridges, viaducts and some very steep saddles.

They're quite comfortable, if fairly chilly at times, having that gentle "clackety-clack" side-to-side sway, reminiscent of more conventional rail transport.

There's excellent visibility, the travel is quiet enough for a good conversation and the clear plastic "sides" can be put up to give limited rain protection.

In rail mode the steering wheel is (obviously) rendered inoperable. However, on the rails, the "driver" retains control over acceleration, slowing and stopping.

The rail carts do about 20km/h, which is perfect for taking in the beguiling scenery or back blocks farms and rugged bushland.

On my trip, the most exciting incident was a near-collision with a wild goat - one of thousands in the East Taranaki hills - which jumped across the tracks of an old railway river bridge at the very second we drove onto it.

Ease of conversion from road to rail use seems to be the key to the success of these vehicles, a transformation reminding me - in principle, anyway - of how those Sealegs amphibious boats operate.

I can tell you that the back tyres sit on the track, providing the traction required in rail mode, but I cannot reveal a lot more than that.

Balme put much money and resources into the venture which has already started to boost local tourism. He is keen to guard his technology as long as possible, having fielded in the past week inquiries from folk keen to run similar ventures along disused tracks in Northland and Australia.

By Paul Charman

Posted on November 02, 2012 at 9:12 PM

Ready or not, unmanned drones may soon be a staple of American life

If you're worried about companies like Facebook and Google violating your privacy, just wait until you have unmanned aerial drones flying around your house.

While this may sound like some far-fetched futuristic scenario, it's actually something that could become a reality by 2015. That's because an aviation bill signed into law by President Obama earlier this year will allow domestic use of "unmanned aircraft systems" by both the government and private citizens and businesses for the first time. In other words, if the Federal Aviation Administration meets its deadline for integrating unmanned drones into national airspace, we could see unmanned aircraft flying around our neighborhoods in just three years' time.

Naturally, this raises some significant privacy and safety concerns, which is why the Brookings Institute this week held a discussion panel to debate the implications that domestic drones will have for private citizens. Although there was certainly disagreement on the panel, all four participants basically believed that unmanned drones were a potentially useful technology for domestic use as long as the government put in the proper restrictions on their use by both the public and private sector.

Just what those restrictions will be, however, is certainly still up for debate. Paul Rosenzweig, a visiting fellow at the Heritage Foundation and the founder of Red Branch Consulting, said that drones had plenty of natural applications for law enforcement, particularly when it comes to surveillance of the US-Mexico border where border patrol agents have difficulty efficiently monitoring thousands of miles of space. However, he also acknowledged that law enforcement agencies needed to be given strict limitations on how they can use drones. For instance, he said that doing surveillance along the border would not give law enforcement the right to deploy surveillance on local Tea Party or American Civil Liberties Union (ACLU) chapters that happened to be meeting in the area.

"Without developing an oversight mechanism to prevent misuse we won't ever get to see the beneficial uses of drones," he said.

Catherine Crump, a staff attorney at the ACLU, expressed concerns about law enforcement gaining access to unmanned drones if private citizens weren't given the same type of access. She also said she was alarmed at how many law enforcement officials she's talked with were interested in attaching non-lethal weapons such as tear gas canisters to drones and using them for crowd control.

"I always thought that it was far-fetched but law enforcement agents have expressed serious interest in [weaponised drones] because they can contain crowds without having any officers present," she said. "One of the things I wonder about is will drones become a tool of law enforcement agents but will private citizens be restricted from using them due to safety concerns?"

Crump also said that drones were more problematic from a civil liberties perspective because they were much less costly to operate and maintain than manned aircraft such as helicopters that police currently use for aerial surveillance.

John Villasenor, a nonresident fellow at the Brookings Institute, shared Crump's view that unmanned drones can be particularly problematic for privacy issues since they're so much smaller and harder to detect than traditional aerial craft.

"FPV aircraft can make it easier to spy," he said. "A pilot who's sitting in a car parked 10 blocks away while operating a drone is less likely to get caught... Sensitive government and military facilities could find it harder to detect a small unmanned drone."

But while Villasenor acknowledged that unmanned drones created real risks for privacy and security, he also said they also provide life-saving technologies that are too beneficial to ignore, such as the ability to easily search for stranded survivors that need medical attention in the wake of natural disasters. Villasenor said some of the biggest issues in deploying unmanned drones domestically will be how to safely integrate potentially tens of thousands of new vehicles into American airspace.

"It's a complex problem," he said. How in the world are we going to navigate the safety challenges of having tens of thousands of these unmanned drones being used for assorted reasons? The sheer math of it says that we're going to have some hiccups along the way."

Kenneth Anderson, a nonresident senior fellow at Brookings, also thought that safety was a major concern for the future of unmanned drones and warned that the technology would face an immediate public backlash if drones were involved in high-profile accidents.

"It wouldn't take many safety incidents of a serious kind to shut the whole thing back down," he says.

Background: What the drone invasion looks like:http://www.networkworld.com/slideshow/28277...

First Published in ComputerWorld
Link to original article:http://computerworld.co.nz/news.nsf/technology/ready-or-not-unmanne...

Posted on October 18, 2012 at 9:22 PM

Martian landscape revealed

NASA has released a stunning panoramic image of the Martian landscape which it hailed as the "next best thing to being there".

The image was compiled from 817 images taken between December 21, 2011, and May 8, 2012, while Mars rover Opportunity was stationed on an outcrop informally named Greeley Haven, on a segment of the rim of the ancient Endeavour Crater.

The scene, recorded from a mast-mounted colour camera on top of Opportunity, shows the rover's own solar arrays and deck in the foreground, and fresh track marks from the rover's exploration.

"The view provides rich geologic context for the detailed chemical and mineral work that the team did at Greeley Haven over the rover's fifth Martian winter, as well as a spectacularly detailed view of the largest impact crater that we've driven to yet with either rover over the course of the mission," said Jim Bell of Arizona State University, Tempe, Pancam lead scientist.

The crater spans 22 kilometres in diameter.

North is at the centre of the image, while south is at both ends.

The colours of the image has been altered to emphasise differences between materials in the scene, Nasa explained.

The release of the image comes shortly after Opportunity completed its 3000th Martian day the red planet on July 2.

Opportunity and its twin, Spirit, landed on Mars in January, 2004 for missions originally planned to last for three months.

Nasa's next-generation Mars rover, Curiosity, is on course for landing on Mars next month

Posted on October 18, 2012 at 9:21 PM

Earth Hit by Powerful Solar Flare

A powerful solar flare was unleashed from a massive sunspot Thursday, blocking high-frequency radio communication in the Northern Hemisphere and producing the potential for auroras to rage across the northern United States......



Posted on October 18, 2012 at 9:20 PM

Photo + Story - What is this Martian mystery?

What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars, according to Nasa.

What created this unusual hole in Mars? Scientists are investigating it as a possible spot for life on the Red Planet. Photo / Nasa

The hole appears to be an opening to an underground cavern, partly illuminated on the image right.

Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern.

Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life, Nasa reports.

These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers.

- nzherald.co.nz

Posted on October 18, 2012 at 9:19 PM

Time Zone Converter – Time Difference Calculator

Time Zone Converter – Time Difference Calculator
Find the time difference between several cities with the Time Difference Calculator. Provides time zone conversions taking into account daylight saving time (DST), local time zone and accepts present, past or future dates.
For current time anywhere in the world, please use The World Clock.

Posted on September 23, 2012 at 10:09 PM

Philip Duncan's Weekly Column

A Weather related Weekly Column written by Philip Duncan – Head Weather Analyst at Weatherwatch.co.nz

Posted on September 23, 2012 at 8:41 AM

International Weather Events

Reports and Discussion on International Weather Events

Posted on September 23, 2012 at 8:40 AM

Ohauiti Weather Station - Longest Wet Period

Longest Wet Period 11 days to 28 June 2012

More local weather records available athttp://www.ohauitiweather.co.nz/weather/record.htm...

Posted on September 16, 2012 at 8:11 AM


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Wednesday's national forecast

Posted by WW Forecast Team on Wed, 10/10/2018 - 04:00

A northwesterly airflow lies over New Zealand today, a cold southerly change moves onto the lower South Island early this morning however then pushing northwards during the day.

Northland, Auckl…

Posted on October 10, 2018 at 12:12 PM


Total Posts: 478
Joined: February 27, 2012

Tuesday's national forecast

Posted by WW Forecast Team on Tue, 09/10/2018 - 03:44

Anticyclonic for much of New Zealand today however there will be a westerly quarter airflow moving over the country.

Northland, Auckland, Waikato & Bay Of Plenty
A mix of sun and cloud with wes…

Posted on October 10, 2018 at 12:06 PM


Total Posts: 478
Joined: February 27, 2012

Monday's National Forecast

Posted by WW Forecast Team on Mon, 08/10/2018 - 05:03

An anticyclone brings mainly settled conditions to New Zealand today, despite this there will be some areas of cloud and the chance of a shower or two for certain regions.

Upper North Island

Posted on October 10, 2018 at 12:03 PM