Western disturbances (WDs) are upper-level synoptic-scale systems embedded in the subtropical westerly jet stream (STWJ), often associated with extreme rainfall events in north India and Pakistan during boreal winter. Here, a tracking algorithm is applied to the upper-tropospheric vorticity field for 37 years of ERA-Interim reanalysis data, giving a catalogue of over 3000 events. These events are analysed in a composite framework: the vertical structure is explored across a large number of dynamic and thermodynamic fields, revealing a significant northwestward tilt with height, strong ascent ahead of the centre, which sits above the maximum surface precipitation, and a warm-over-cold, dry-over-moist structure, among other signatures of strong baroclinicity.
Original Source [2]
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/evolution-seasonality-and-impacts-western-disturbances
[2] https://rmets.onlinelibrary.wiley.com/doi/epdf/10.1002/qj.3200
[3] http://admin.indiaenvironmentportal.org.in/category/author/kieran-m-r-hunt
[4] http://admin.indiaenvironmentportal.org.in/category/author/andrew-g-turner
[5] http://admin.indiaenvironmentportal.org.in/category/author/len-c-shaffrey
[6] http://admin.indiaenvironmentportal.org.in/category/journal/quarterly-journal-royal-meteorological-society
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/atmosphere
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rainfall-pattern
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/extreme-weather-events
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/n-c-america
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/storms
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pakistan
[14] http://admin.indiaenvironmentportal.org.in/category/thesaurus/south-asia