Dr. David M. Schultz


Cold Surges

After the Superstorm of March 1993 occurred, a surge of cold arctic air flooded the Eastern U.S. Eventually this cold air made its way down to Central America. We tracked this cold air and addressed several issues such as: (a) how does the cold air affect the sea-surface temperature; (b) what is the structure of the surge as it moves into the tropics; (c) what are the implications for the planetary-scale flow; and (d) what determines how far south the cold air gets? This work resulted in two manuscripts: the first one, "The 1993 Superstorm cold surge: Frontal structure, gap flow, and tropical impact" appears in the January 1997 issue of Monthly Weather Review. The second one, "Planetary- and synoptic-scale signals associated with Central American cold surges" has been published in the January 1998 Monthly Weather Review.

This is an image of the Superstorm at 4 pm EST March 13, 1993. The center of the low is near Virginia and the cold surge can be seen as two arc-shaped clouds: one over the Pacific Ocean, the other in Honduras.

This research on cold surges has led me (along with Jim Steenburgh of the University of Utah and Brian Colle of the University of Washington) to pursue mesoscale modeling of the March 1993 surge to answer questions which could only partially be addressed from our previous observational work. More specifically, we are looking at the structure and evolution of the leading edge of the cold surge on the mesoscale and the nature of the gap flow through the Isthmus of Tehuantepec. An animation of the model simulation over the Gulf of Tehuantepec can be viewed here. An abstract of this work can be found elsewhere.

Here is an image from another site showing the cooling associated with a wind event. Here are some more images of these wind jets from Dudley Chelton at Oregon State University.

Further Reading:

Schultz, D. M., and W. J. Steenburgh, 1999: The formation of a forward-tilting cold front with multiple cloud bands during Superstorm 1993. Mon. Wea. Rev., 127, 1108-1124. [AMS] [PDF] [HTML]

Steenburgh, W. J., Schultz, D. M., and B. A. Colle, 1998: The structure and evolution of gap outflow over the Gulf of Tehuantepec, Mexico. Mon. Wea. Rev., 126, 2673-2691. [AMS] [PDF]

Schultz, D. M., W. E. Bracken, and L. F. Bosart, 1998: Planetary- and synoptic-scale signals associated with Central American cold surges. Mon. Wea. Rev., 126, 5-27. [AMS] [PDF]

Schultz, D. M., W. E. Bracken, L. F. Bosart, G. J. Hakim, M. A. Bedrick, M. J. Dickinson, and K. R. Tyle, 1997: The 1993 Superstorm cold surge: Frontal structure, gap flow, and tropical impact. Mon. Wea. Rev., 125, 5-39; Corrigenda, 125, 662. [AMS] [PDF]

If you have any further questions about the research discussed here, or desire a manuscript, please feel free to write to me: david.schultz@noaa.gov.

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David Schultz david.schultz@noaa.gov
Last update: 7 April 2002