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Improving the numerical prediction of a cyclone in the Mediterranean by local potential vorticity modifications
Author(s) -
Argence Sébastien,
Lambert Dominique,
Richard Evelyne,
Pierre Chaboureau Jean,
Philippe Arbogast Jean,
Maynard Karine
Publication year - 2009
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.422
Subject(s) - cyclogenesis , climatology , mesoscale meteorology , potential vorticity , environmental science , cyclone (programming language) , tropopause , troposphere , precipitation , numerical weather prediction , meteorology , tropical cyclogenesis , vorticity , water vapor , atmospheric sciences , hydrostatic equilibrium , vortex , geology , geography , physics , field programmable gate array , quantum mechanics , computer science , computer hardware
This study explores the benefit that can be drawn from incorporating local potential vorticity (PV) modifications into a numerical forecast. The case under study is the severe cyclogenesis that occurred in the Western Mediterranean from 9 to 12 November 2001. This case was shown to be extremely sensitive to the upper‐level flow, which governed to a great extent the deepening of the depression and the location and intensity of its associated precipitation. Corrections of PV were guided by METEOSAT‐7 water vapour observations and restricted to the upper troposphere, mainly altering the topography of the dynamical tropopause. Using both the French operational global model ARPEGE and the non‐hydrostatic mesoscale model Meso‐NH, it is shown that carefully designed PV corrections lead to a substantial improvement in the simulation of the storm, both in terms of surface pressure, cloud cover and precipitation forecasts. Furthermore, the impact of the modifications is shown to be a maximum when they are introduced at the time corresponding to the incipient stage of cyclogenesis. Copyright © 2009 Royal Meteorological Society