Starship Asterisk*

Luiz wrote:
A portion of Typhoon Varnei http://en.wikipedia.org/wiki/Tropical_Storm_Vamei has indeed crossed equator.

Luiz wrote:
There were another South Atlantic hurricane besides 2003 Catarina, check November 19th 1980 in the same region.

http://en.wikipedia.org/wiki/South_Atlantic_tropical_cyclone wrote:
<<South Atlantic tropical cyclones are unusual weather events that occur in the southern hemisphere. Strong wind shear (which disrupts cyclone formation) and a lack of weather disturbances favorable for tropical cyclone development make any hurricane-strength cyclones extremely rare. If a "hurricane season" were to be demarcated in the South Atlantic, it would most likely be the opposite of the North Atlantic season, from November to the end of April with mid-March being the peak when the oceans are warmest in the Southern Hemisphere. These tropical cyclones would be given identifiers starting with SL in the future.

According to a study published in 2008, there were 92 subtropical cyclones in the Southern Atlantic between 1957 and 2008.>>

do_japan wrote:Why is there no record of Hurricanes/Typhoons in the southern hemisphere before 1950?

Henk wrote:
I'm a bit surprised by the remark in the original text that 'evaporation of warm water gives hurricanes their energy'.

Evaporation costs energy, it's the condensation afterwards that can give off the energy again...

Polar lows have been referred to by many other terms, such as polar mesoscale vortex, Arctic hurricane, Arctic low, and cold air depression. Today the term is usually reserved for the more vigorous systems that have near-surface winds of at least 17 m/s.[30]-- Wikipedia-Polar Low

Stephen Rasey wrote:Polar Vortex and Polar Cyclones are different things.

A polar vortex that you describe has it's eye on or near the pole.

A polar cyclone, or a polar low, such as the Nov. 2011 storm described in the Bering Sea is warm center convection cyclonic storm, albeit with a very cold upper atmosphere over a cool sea. It is a traveling low pressure storm system. http://nsidc.org/arcticmet/patterns/polar_low.html

Stephen Rasey wrote:

“The most powerful storm to affect the Bering Sea coast of Alaska in 37 years is pounding Alaska’s west coast and Eastern Siberia with hurricane-force winds, a destructive storm surge up to 7 feet high, waves up to 35 feet high, and blinding snow,” ...." central pressure of 945 mb." ... "6 foot storm surge in Nome Alaska." -- November 8-9, 2011.

That sounds like a "hurricane" to me. A polar cyclone, but a hurricane by another name.

Should storms like these be on the map?

• No!

http://en.wikipedia.org/wiki/Polar_cyclone wrote:

[b][color=#0000FF]Hubble view of the colossal [u]cold core[/u] polar cloud on Mars[/color][/b]

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<<A polar vortex (also known as Polar cyclones, polar vortices, Arctic cyclones, sub-polar cyclones, and the circumpolar whirl) is a persistent, large-scale cyclone located near one or both of a planet's geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere. They surround the polar highs and lie in the wake of the polar front. These cold-core low-pressure areas strengthen in the winter and weaken in the summer. They usually span 1,000–2,000 kilometers in which the air is circulating in a counter-clockwise fashion (in the northern hemisphere). The reason for the rotation is the same as any other cyclone, the Coriolis effect.

Other astronomical bodies are also known to have polar vortices, including Venus (double vortex - that is, two polar vortices at a pole ), Mars, Jupiter, Saturn and Saturn's moon Titan.>>

http://en.wikipedia.org/wiki/Tropical_cyclone wrote:

[b][color=#FF0000]Tropical cyclones are (condensation warmed) [u]warm core[/u] circulations whose strongest winds are in the near surface boundary layer.[/color][/b]

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<<A tropical cyclone is a storm system characterized by a low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. They usually span 300–700 kilometers. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor contained in the moist air. They are fueled by a different heat mechanism than other cyclonic windstorms such as nor'easters, European windstorms, and polar lows. The characteristic that separates tropical cyclones from other cyclonic systems is that at any height in the atmosphere, the center of a tropical cyclone will be warmer than its surroundings; a phenomenon called "warm core" storm systems. A tropical cyclone's primary energy source is the release of the heat of condensation from water vapor condensing, with solar heating being the initial source for evaporation. Therefore, a tropical cyclone can be visualized as a giant vertical heat engine supported by mechanics driven by physical forces such as the rotation and gravity of the Earth. In another way, tropical cyclones could be viewed as a special type of mesoscale convective complex, which continues to develop over a vast source of relative warmth and moisture. While an initial warm core system, such as an organized thunderstorm complex, is necessary for the formation of a tropical cyclone, a large flux of energy is needed to lower atmospheric pressure more than a few millibars (0.10 inch of mercury). The inflow of warmth and moisture from the underlying ocean surface is critical for tropical cyclone strengthening. A significant amount of the inflow in the cyclone is in the lowest 1 kilometre of the atmosphere.>>

“The most powerful storm to affect the Bering Sea coast of Alaska in 37 years is pounding Alaska’s west coast and Eastern Siberia with hurricane-force winds, a destructive storm surge up to 7 feet high, waves up to 35 feet high, and blinding snow,” ...." central pressure of 945 mb." ... "6 foot storm surge in Nome Alaska." -- November 8-9, 2011.

Stephen Rasey wrote:The subject hurricane history map in today’s APOD fails this White Lie test. It purports to show "every hurricane reported" since 1851. That begs the question, "Reported to whom?" Did the author get every hurricane reported by every ship’s captain? If so, why does the Australia region of the map look so very different from the one provided by the Australian government?
http://www.bom.gov.au/cgi-bin/silo/cycl ... =all&loc=0

As grover pointed out above the US did not really collect Hurricane tracking data for the east and south hemisphere until 1978.
So it is necessary to be skeptical of this map. It represents uneven data collection probably more than tells up about the distribution of hurricanes. There are more hurricanes plotted in the north Atlantic portion of the map because the US was looking for them there longer, and intently after Galveston 1900.

tjjharris wrote:The hurricane tracks page says "every" hurricane. In the way most people look for themselves in a group portrait, I look first for the track of the hurricanes which have hit my home. I live in Hawaii, and we've had only two, and recently at that, yet I see no hurricane tracks in the pacific which come up to Hawaii. Hurricane Iniki moved almost due west, and then when due south of us, came right up to smash Lihue, Kauai, "eye on". They're still rebuilding. No track for Iniki seen however. Maybe it's just too faint to see?

Boomer12k wrote:Just because we don't worry about Hurricanes does not mean we have nothing to worry about in the Pacific Northwest. We don't usually worry about Tornadoes, but one tore up a nearby town a couple of years ago...the first I have ever heard of one touching down in my area, and I am 59. We don't get a Hurricane, but we get 80-120 MPH winds, and cyclonic wave action off the Pacific Ocean. The 1962 Columbus Day storm is still remembered.
We also get Ice Storms, and snow storms one a decade or so. Bad flooding and such too...we can have drought and bad fire seasons, and even small, but damaging Earthquakes, And Mt. St. Helens erupted in 1980....PLENTY TO WORRY ABOUT!!! But tonight is nice and pleasant and I am typing this while at the telescope.

So, regardless of your troubles, I want my APOD friends to be WELL AND HAPPY!!! Safe and Sound.

:---[===]*

do_japan wrote:
Why is there no record of Hurricanes/Typhoons in the southern hemisphere before 1950?

rhapsody58 wrote:The map is also missing at least one other track. In 2004, hurricane Catarina hit Brazil, the first South Atlantic storm on record to be strong enough to reach hurricane level. South Atlantic tropical cyclones are rare, as atmospheric conditions are much different than those in the North.

StarDawg wrote:Usually, APOD is all about astronomy.

APOD Robot wrote: Hurricane Paths on Planet Earth

... evidence is accumulating that hurricanes are, on the average, more common and more powerful in the North Atlantic Ocean over the past 20 years.

biddie67 wrote:
It looks like if the land mass of the North American continent weren't there to deflect hurricanes
that the Asian coastline would get a lot more bad storms.

http://en.wikipedia.org/wiki/Typhoon#Frequency wrote:

[b][color=#0000FF]Typhoon Tip (1979) was the largest tropical cyclone on record, with a diameter of 2,220 km. With 10-minute sustained winds of 260 km/h, Typhoon Tip is the strongest cyclone in the complete tropical cyclones. The typhoon was also the most intense tropical cyclone on record with a pressure of 870 mbar.[/color][/b]

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<<Nearly one-third of the world's tropical cyclones form within the western Pacific. This makes this basin the most active on Earth. Pacific typhoons have formed year round, with peak months from August to October. The peak months correspond to that of the Atlantic hurricane seasons. Along with a high storm frequency, this basin also features the most globally intense storms on record. One of the most recent busy seasons was 2004. Tropical cyclones form in any month of the year across the northwest Pacific ocean, and concentrate around June and November in the northern Indian ocean. The area just northeast of the Philippines is the most active place on Earth for tropical cyclones to exist. Across the Philippines themselves, activity reaches a minimum in February, before increasing steadily through June, and spiking from July through October, with September being the most active month for tropical cyclones across the archipelago. Activity falls off significantly in November. The most frequently impacted areas of the Philippines by tropical cyclones are northern Luzon and eastern Visayas. A ten year average of satellite determined precipitation showed that at least 30 percent of the annual rainfall in the northern Philippines could be traced to tropical cyclones, while the southern islands receive less than 10 percent of their annual rainfall from tropical cyclones.>>

tjjharris wrote:The hurricane tracks page says "every" hurricane. In the way most people look for themselves in a group portrait, I look first for the track of the hurricanes which have hit my home. I live in Hawaii, and we've had only two, and recently at that, yet I see no hurricane tracks in the pacific which come up to Hawaii. Hurricane Iniki moved almost due west, and then when due south of us, came right up to smash Lihue, Kauai, "eye on". They're still rebuilding. No track for Iniki seen however. Maybe it's just too faint to see?