Tropical Cyclone Distribution
From AuroraWiki
Tropical Cyclone Distribution varies based on the several factors governing formation of a tropical storm. Such storms form above the warm waters of tropical currents, typically between ten and twenty degrees of latitude, toward the hemisphere experiencing summer. They follow an evolution from tropical depression, through tropical storm, to typhoon, cyclone, or hurricane, the terminology varying in the different ocean basins.
- Main Article: Tropical cyclone on Wikipedia
Contents |
Tracks of individual storms vary wildly, influenced by uncountable factors. Prediction of the path of a given storm is inaccurate, but as the naval sciences and military agencies of Aurora increase cooperation and the number of observation stations, it is improving. At least the anticipated time of landfall can be determined, some plus or minus six hours, two days ahead. That amount of warning is sufficient to save many lives, in countries with decent communication and transportation.
Seasons
| Zone | Ocean basin | Season |
|---|---|---|
| A | Mid-Patronic | June-November, weak or nonexistent in years when the Xianbian High is out in the Patronic |
| A1 | Topal | July-October, even when zone A is weak |
| B | North Machweo | May-October, but no cyclonic storms at all in years the Xianbian High is over the Machweo Sea |
| C | Karic | July-October |
| D | North Cidalian | July-November |
| E | South Patronic | January-July, scattered few through September |
| F | West Majonian | November-June in north, January-May in south |
| G | South Machweo | December-June |
| H | South Cidalian | December-July |
| Abecean | tropical cyclones don't form |
Hatching grounds
Atmospheric disturbances near the Intertropical Convergence Zone collect as an intensified low in that already-low-pressure trough. The first recognized state is termed a tropical depression. It picks up rotation from coriolis forces, which in turn intensifies the low pressure and strengthens winds. If sustained wind speed is above 30 knots, the system is termed a tropical storm and is named by weather authorities. From inception, prevailing winds steer the system westward. Depressions can remain weak, can strengthen to any level on the scale, and can vary stronger and weaker - most often weakening over land and strengthening over the warmest waters. Eastern and equator-ward edges of the illustrated zones are where the most cyclones start, though occasionally they can spring up anywhere in the zones.
Paths
A few typical storm tracks are illustrated. Many storms never strike land. Southern-hemisphere storms eventually trend southward, and even can curve back southeast if far enough from the equator. Northern-hemisphere tracks bend to north, then northeast.
Karic storms seldom reach above Category 3, at 85-90 knots. Late-season Cidalian cyclones often reach Category 5, with as many as five of those striking land per year in each hemisphere. Cidalian storms are often the broadest, spanning as much as 1100 km, defined as the diameter within which winds are at least tropical-storm strength - 30 knots. Machweo storms seldom live long enough to grow to huge size, but the very warm waters do drive strengths to category four often.
South Cidalian cyclones sometimes cross the Kijanan neck. Even if they weaken to depressions, they will be dragging huge amounts of rain ashore, and will often strengthen back to cyclone strength in the South Machweo. No more than one tropical depression forms as a storm system in the Abecean every five or six years, and none have ever been observed to have. attained tropical storm strength. The currents in the critical 10-20 degree south hatching grounds simply aren't warm enough to generate nor sustain strong disturbances. The south Abecean has plenty of storms, even gale-force ones, they just aren't heat-driven cyclonic ones.
South Patronic cyclones have on occasion crossed into the Paahdemeri Sea. Karsos is not mountainous enough to totally blunt their force, and waters there can be plenty warm. At least five times a storm has briefly regained hurricane strength once across the Karsosian isthmus, but that's rare.
West Majonian storms can cross the north end of Shurku and strengthen as South Patronic storms. With a "running start", these are among the most dangerous weather systems in the South Patronic. On the one hand those greatly slowed by the land crossing generate torrential rains. On the other, those retaining high winds tend to track southwest, with the longest possible South Patronic paths before reaching land. Eastern Samir has seen great loss of life from such crossover storms, without them even making landfall -- rain amounts of over half a meter in one day can occur, as when in 2104 a category 3 storm skimmed the entire Samir coast to latitude 46 south.
