Re-examination of the I-5 dust storm
Article first published online: 31 JAN 2013
©2013. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Atmospheres
Volume 118, Issue 2, pages 627–642, 16/28 January 2013
How to Cite
2013), Re-examination of the I-5 dust storm, J. Geophys. Res. Atmos., 118, 627–642, doi:10.1002/jgrd.50131., , , , , , and (
- Issue published online: 1 MAR 2013
- Article first published online: 31 JAN 2013
- Accepted manuscript online: 4 JAN 2013 08:28PM EST
- Manuscript Accepted: 20 DEC 2012
- Manuscript Revised: 30 NOV 2012
- Manuscript Received: 23 OCT 2012
- dust storm;
- mesoscale adjustments
 The infamous dust storm over the thanksgiving holiday of 1991 that led to loss of life from numerous automobile accidents on Interstate 5 (I-5) has been re-examined. Pauley et al. (1996) conducted an earlier investigation of this dust storm following the tenets of Danielsen's paradigm—a paradigm that links the tropopause fold phenomenon and a balanced thermally indirect circulation about the upper level jet stream. However, a cursory examination of mesoscale structures in the storm from the North American Regional Reanalysis (NARR) indicated evidence of a low-level unbalanced thermally direct circulation that demanded further investigation using a high-resolution Weather Research and Forecasting (WRF) model simulation. Principal results from the present study follow: (1) Although the model simulation showed evidence of a weak indirect circulation in the upper troposphere in support of the Danielsen's paradigm, the dynamic control of the storm stemmed from the lower tropospheric mesoscale response to geostrophic imbalance. (2) A lower tropospheric direct circulation led to mass/temperature adjustments that were confirmed by upper air observations at locations in proximity to the accident site, and (3) boundary layer deepening and destabilization due to these mesoscale processes pinpointed the timing and location of the dust storm. Although the present study does not underestimate the value of analyses that focus on the larger/synoptic scales of motion, it does bring to light the value of investigation that makes use of the mesoscale resources in order to clarify synoptic-mesoscale interactions.