RAMMB Satellite Case Studies

The 31 May 1996 Pre-tornadic Storm Environment Over Colorado and Kansas, From a GOES Perspective

Published: February 25, 2000

This case study is being presented to demonstrate what might be learned about the pre-tornadic storm environment in and around Colorado and Kansas on 31 May 1996. While closely linked with the earlier case in this series on this outbreak, for this presentation we are limited to the more standard mode of GOES satellite operations, e.g., imagery at 15 minute intervals. Both GOES-9 and GOES-8 digital, McIDAS formatted data, that cover the area and time of interest, can be found on the CIRA-RAMM Team's FTP server. Log on to "canopus.cira.colostate.edu" (or ""), using "anonymous" and then your e-mail address for the password. The data is located in the "/96152_1min/prestorm/" directory.

The GOES-9 datasets include 26 visible images from 11:00:13 to 18:00:13 UTC (AREA1040 - AREA1065), 58 IR images from 03:00:13 to 18:00:13 UTC (AREA3908 - AREA3965), 58 water vapor images from 03:00:13 to 18:00:13 UTC (AREA4008 - AREA4065) and 37 "fog product" images (e.g., difference images from the 10.7 and the 6.7 micron channels) from 03:00:13 to 12:00:14 UTC (AREA6908 - AREA6944).

GOES-8 datasets are available as follows: 16 visible images from 17:01:xx to 21:15:xx UTC (AREA8861 - AREA8876) and 16 IR images over the same time span (AREA4861- AREA4876).

Morning analyses on 31 May 1996 found a weak longwave trough over the western U.S. and a number of significant low-level boundaries in the central Plains. These included a warm front in eastern Kansas and Oklahoma; an east-west oriented outflow boundary in Kansas, analyzed as part of the warm front by NCEP (NWS' National Center for Environmental Prediction) on the MSLP (mean sea-level pressure) analysis; a surface low in southeast Colorado; and a convergence boundary along a trough line which stretched from the low into southeastern New Mexico. The airmass over most of the central plains was unstable and expected to become even more so as the day progressed, due to diurnal heating and moisture advection from the Gulf of Mexico.

Depending upon your needs, please review the "basic", first level, or the "advanced", more detailed, discussion of the precursor environment to the tornadic outbreak. Better yet, visit both of them!