A Case Study of Explosive Cyclogenesis in the Eastern Pacific Ocean 14- 17 December 1987
Abstract
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 Satellite (GOES) digital imagery. Forecasts for this cyclone by the Navy Operational Global Atmospheric Prediction System (NOGAPS 3.0) and NMC Nested Grid Mesh (NGM) forecasts initialized at 12 UTC 14 December are also evaluated. Quasi-Langrangian budgets of mass and vorticity are computed to understand the factors responsible for the development of this intense cyclone. The initial surface development occurs within a strong baroclinic southeast of a significant short-wave trough aloft. Rapid intensification is accompanied by large cyclonic vorticity advection in the upper troposphere as the surface cyclone moves under the divergent quadrant of a 250 mb jet streak. A key element in this development is the superposition between the pre-existing surface low and upper level short wave trough in a favorable weak stability environment. These observations support earlier studies that upper level forcing acts as a critical catalyst in initiating eastern ocean explosive development. Theses. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1989
- Accession Number
- ADA219543
Entities
People
- Jan Curtis
Organizations
- Naval Postgraduate School