What is Tropical Upper Tropospheric Trough?
A '''Tropical Upper Tropospheric Trough''' ('''TUTT''') is a [[trough (meteorology)|trough]] in upper-level (at about 200 hPa) [[tropics]]. Its formation is usually caused by the expansion of the [[Trough of Westerlies Wind]] to the tropics. It can also develop from the inverted trough adjacent to a upper level anticyclone. TUTTs are different from mid-latitude troughs in the sense that they are maintained by subsidence warming near the [[tropopause]] which balances radiation cooling. TUTTs sometimes bring a large amount of vertical [[wind shear]] over [[tropical wave|tropical disturbances]] and [[tropical cyclone|cyclones]] so TUTTs can reduce cyclone development. But, there are also times when TUTTs help start tropical cyclones or make them stronger by providing additional forced ascent near the storm center and an efficient outflow channel in the upper [[troposphere]]. Moreover, under specific circumstances, TUTTs can grow into upper cold lows and may enhance the development of low level disturbances. ==Other websites== * [http://www.cs.uu.nl/wais/html/na-dir/meteorology/storms-faq/part1.html FAQs on Hurricanes, Typhoons And Tropical Cyclones] {{Webarchive|url=https://web.archive.org/web/20070403092553/http://www.cs.uu.nl/wais/html/na-dir/meteorology/storms-faq/part1.html |date=2007-04-03 }} * [http://hkcoc.weather.com.hk/cycdict/key=hot.htm#8 Definition of TUTT in Traditional Chinese] {{Webarchive|url=https://web.archive.org/web/20150909150213/http://hkcoc.weather.com.hk/cycdict/key=hot.htm#8 |date=2015-09-09 }} * {{in lang|fr}} [http://entreprise.meteofrance.com/jsp/site/Portal.jsp?&page_id=14199&document_id=23901&portlet_id=64720 Tropical textbook : from trade winds to cyclones (2 vols). The part 8.4 deals with TUTT] {{Webarchive|url=https://archive.today/20121216085839/http://entreprise.meteofrance.com/jsp/site/Portal.jsp?&page_id=14199&document_id=23901&portlet_id=64720 |date=2012-12-16 }}.Florent Beucher, 25 mai 2010, Météo-France, 897 pp. {{weather-stub}} [[Category:Tropical cyclones]] [[Category: