Analyzed potential vorticity fields for explosive and non-explosive cyclogenesis events during FGGE.
Kirchoffer, Peter J.
MetadataShow full item record
Potential vorticity and jet streak properties associated with 23 explosive and non-explosive cyclones from the western North Atlantic and western North Pacific Oceans are analyzed for the period 17 January to 23 February 1979. ECMWF analyses with FGGE data are used to represent the 300 mb wind fields over these ocean areas. Relative maxima in potential vorticity are present upstream of all cyclones. Storm tracks with respect to the potential vorticity maxima are counter-clockwise with the greatest sea-level pressure decreases occurring when the storm is to the east or southeast of the maximum, whereas pressure falls diminish when the cyclone is north of the maximum. Only five of the 23 cases have a pre-existing potential vorticity lobe that becomes superposed with the surface feature and enhances cyclogenesis. In the remaining cases, the cyclone and potential vorticity lobe propagate and develop concurrently. The presence of a jet maxima over the storm is a major factor in storm development with large pressure falls being directly related to higher 300 mb wind speeds. In 20 of 23 cases, the storm is in the left-front jet quadrant at some time during its development. A statistical analysis demonstrates that forecasting the actual values of 12-h pressure falls from the potential vorticity and wind fields is difficult. However, forecasting development within one of three intensity categories using a discriminate analysis technique may approach 90% accuracy for explosive cyclones.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Curtis, Jan. (Naval Postgraduate School, 1989);An explosive cyclogenesis event that occurred in the eastern Pacific Ocean on 14-17 December 1987 is investigated using the National Meteorological Center (NMC) final analyses and Geostationary Operational Environmental ...
Springer, Cory A. (Monterey, California. Naval Postgraduate School, 1994);The short term teleconnections arising from an individual tropical cyclone in the western Pacific were examined using a global operational data assimilation system and forecast model. In the ...
Carson, Jeffrey L. (Monterey, California. Naval Postgraduate School, 1988-06);An explosive cyclone that developed during intensive observation period (IOP)9 of the Genesis of Atlantic Lows Experiment (GALE) is studied. Detailed surface analysis is conducted based on operationally available data, ...