Regional and Mesoscale Meteorology Branch

Enhanced-V

Introduction

This case reviews the use of the enhanced-V signature in the GOES-IR data. Previous studies by McCann(1981) have indicated the value of real-time satellite data in detecting and monitoring severe thunderstorms.

The goal of this teletraining session is to review the correct identification and interpretation of the enhanced-V.

Training Session Options

1. VISITview playback without Audio – You may step through the VISITview file on your own to view the presentation. If talking points are available, you may use these in tandem with going through the slides.

   Create a directory to download the playback file from the following site: http://rammb.cira.colostate.edu/training/visit/training_sessions/enhanced-v/enhanced-v.exe

   After extracting the files into that directory click on the visitlocal.bat file to start the lesson. Advance slides on your own using the navigation controls (i.e., the Next button will advance to the next slide)

Review and Final Remarks

This training installment used the 29 March 1998 Minnesota tornado case to provide an analysis of the enhanced-V satellite signature using GOES data. This signature is an important indicator of severe weather which can be used during weather warning operations to augment radar information. Also shown are imagery from the Jarrell, Texas tornado outbreak. Of particular interest with this case, is the 1km IR AVHRR data which was available for an interesting comparison with GOES.

References/Additional Links

• IR enhancement examples that are useful to detect Enhanced-V cloud top signatures
• McCann, D.W., 1983: The enhanced-V, a satellite observable severe storm signature. Mon. Wea. Rev., 111, 887-894.
• McCann, D.W., 1983: The enhanced-V, a satellite observable severe storm signature. IN: NWA Meteorological Monograph 2-86 “Satellite Imagery Interpretation for Forecasters”, Wash., DC., May 1993. Vol. 2, pp. 4-I-1 – 4-I-8.
• McCann, D.W., 1981: The enhanced-V, a satellite observable severe storm signature. IN:United States National Oceanic and Atmospheric Administration, National Weather Service, Wash., DC., Technical Memorandum (NOAA TM NWS NSSFC-4), March 1981. 31 p., 33, 5-257.
• Heymsfield, G.M., Blackmer, R., Jr., and Schotz, S., 1983: Upper level structure of Oklahoma tornadic storms on 2 May 1979, Pt. 1 Radar and Satellite observations. Journal of the Atmospheric Sciences, Boston, 40(7): 1740-1755.
• Heymsfield, 1983: Upper level structure of Oklahoma tornadic storms on 2 May 1979, Pt. 2, Proposed explanation of V pattern and internal warm region in infrared observations, Journal of the Atmospheric Sciences, Boston, 40(7): 1756-1767.