Weather Around The World, 10/4/16: Ferocious Tropical Cyclones; Historic Floods; Equinox; Harvest Moon


Home / Weather Around The World, 10/4/16: Ferocious Tropical Cyclones; Historic Floods; Equinox; Harvest Moon

As the sun crosses the equator, the transition month of September also features the height of the northern hemisphere tropical cyclone season. Storm-lovers were not disappointed this year, as the strongest storm (anywhere in the world) in three years hit Taiwan and China. And now Hurricane Matthew is devastating part of Haiti and possibly heading for a landfall in the US.

Flooding from torrential rains continues to make news. There’s also a long-range (3 month) forecast, and (of course) global warming news. Let’s go Around The World.

Super-Typhoon Meranti and Typhoons Malakis and Megi: Triple Trouble for Taiwan

Typhoon Meranti passed Taiwan and was headed for mainland China on September 14. Satellite photo courtesy of NOAA

Maybe it’s the alliteration. Typhoons Meranti and Malakis sandwiched Taiwan in September before Typhoon Megi scored a direct hit.

Typhoon Meranti became the strongest storm of the year, maxing out at 190 mile-per-hour winds over the ocean before affecting Taiwan with winds just under Super Typhoon strength (A Super Typhoon has winds over 150 miles per hour.) while passing just west of the island.

After pummeling the southern portion of Taiwan, Meranti slammed into China as a category two storm with winds up to 110 miles per hour. Flooding was widespread in Meranti’s path.

Typhoon Malakis, not as powerful as Typhoon Meranti, passed east of Taiwan on September 18 and aimed at Japan. Graphic courtesy of NOAA.

A second typhoon, Malakis, passed just to the east of Taiwan less than a week later and headed for Japan.

And to complete the trilogy, Typhoon Megi passed over the island on September 27 as the equivalent of a category three hurricane (winds 115-130 miles per hour). Megi went on to make landfall in China as a minimal typhoon (winds 75 miles per hour), and caused widespread flooding inland.

Typhoon Megi’s path took it directly over Taiwan. Graphic courtesy of NOAA.

As if those September storms weren’t enough, a fourth storm, Typhoon Chaba, which formed in September, is now bypassing the beleaguered island of Taiwan and getting ready to affect South Korea and Japan (see latest news on this typhoon below).

Worst Natural Disaster In North Korea’s History

The remnants of a typhoon dumped disastrous rain on North Korea, July 29 to August 2. News trickles out of North Korea at a turtle’s pace, but state media recently called it the worst disaster since the founding of the country in 1945. When North Korea’s secretive regime admits something is bad, it must be REALLY bad. More than 100 (maybe many more) perished, and thousands became homeless.

Though flooding is expected to worsen with global warming (the warmer atmosphere can hold more moisture), this event is probably more a result of North Koreans’ denuding the forested hills for firewood. Water has a clear path down the hills and can accumulate quickly in places with poor drainage.

National Weather Service Forecasts A Warm Three Months

National Weather Service says the next three months will be warmer than normal, especially in the western US. Graphic courtesy of NOAA.

The National Weather Service issues three-month forecasts far into the future. The accuracy declines with time. The NWS forecast for October-November-December indicates a warm period, especially in the western US. Even at this range, the forecast is not terribly good, but it’s right more often than it’s wrong.

Equal Night? What’s Up With That?

The equinox is defined as the precise moment when the sun is directly over the equator — going south in September and north in March.

This year the Autumnal Equinox was at 10:21 a.m. (EDT) on September 22.

The word equinox, meaning literally ‘equal night,’ is not well-chosen. The implication is that night and day are equal; that’s not true. The following are the times of sunrise and sunset on September 22 for various cities (all times are local):

  • Singapore, China                   6:54     7:00
  • Miami, USA                            7:10     7:17
  • Boston, USA                           6:32     6:41
  • London, UK                            6:47     6:58
  • Edinburgh, Scotland             6:59     7:11
  • Norisk, Russia                        6:48     7:10
  • Eureka, Canada                      6:15      6:52
  • Alert, Canada                          5:34     6:23

The cities are listed in order of increasing latitude, and it is clear that the ‘length of day’ increases with distance from the equator.

This conundrum is easily explained: Sunrise and sunset are defined as the times of first and last rays of the sun. It takes several minutes for the disk of the sun to cross the horizon. The increasing difference between day and night with latitude is a result of the decreasing angle the sun’s apparent path makes with the horizon as latitude increases.

Moons: Harvest, Hunter’s, Super, And Mega

At its closest to earth (perigee), the moon is 14% wider and 30% brighter than when it is at its farthest (apogee). Graphic courtesy of NASA.

The Full Moon on September 16, the ‘Harvest Moon,’ was by some definitions, but not all, a Supermoon.

The moon’s path around the earth is not round. The moon’s distance from the earth varies roughly from 222,000 miles to 252,000 miles. A supermoon is, by common definition, one that approaches the earth within 90% of its closest approach (perigee). Whether the September full moon was a Supermoon depends on the definition of ‘closest approach.’ Is it the overall closest approach ever? The closest approach this month? The average closest approach of many cycles?. Let’s just say this Harvest Moon was Supermoonish.

The October (Hunter’s Moon), November , and December full moons will be Supermoons by any definition. The closest approach will be in Novermber, and this full moon has been given the name Megamoon. It will be the moon’s closest approach to the earth, and thus the brightest the moon has been, since 1948.

And the moon won’t be this bright again until 2034.

Sarkozy Denies Climate Change

Nicholas Sarkozy, former and would-be future prime minister of Italy, has announced that he doesn’t believe the burning of fossil fuels has anything to do with changing weather. Like many others, he points to changes in temperature in the past. Mr. Sarkozy should study the matter a little more closely. Of course the temperature has changed in the past — over the course of many millennia.

The increase in temperature that has taken places since the industrial revolution began is matched in the past only by periods of cataclysmic volcanic eruptions or collisions with asteroids.

Furthermore, Mr. Sarkozy might study the science that explains the current increase in temperature — in particular, the fact that carbon dioxide traps heat in the atmosphere. Atmospheric carbon dioxide has increased from 280 to over 400 parts per million since the industrial revolution began. There is no mistaking the fact that greenhouse gas emissions from the burning of fossil fuels are the cause of the recent rise in temperature.

Breaking News: More Cyclonic Trouble

Typhoon Chaba, until a few hours ago a Super-Typhoon, is currently safely offshore between Taiwan and Japan. The latest forecast calls for Chaba to turn northeastward and shoot the narrow gap between southern South Korea and southwestern Japan, causing winds over 100 miles per hour on both coasts, then diminish in strength as it skirts the western coast of central japan.

The official National Hurricane Center forecast for Matthew brings it within 50 miles of the Florida coast, then takes it along the CArolina coast to a direct hit on the Outer Banks. Forecast courtesy of NOAA.

In the Atlantic Basin, Hurricane Matthew, currently category four (winds around 140 miles per hour), is battering western Haiti and eastern Cuba.

The latest National Hurricane Center forecast calls for the storm to ravage the central and northern Bahamas, stay just offshore of Florida, where the governor has declared a state of emergency, and take aim at coastal North Carolina.

Longer term there is a possibility that Matthew will affect coastal New York and New England.

Decoded Science will have a complete report on Matthew if it threatens the US later in the week.

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