Date: Fri, 9 Apr 2004 13:33:49 -0600 (MDT) From: Bob Rozumalski Subject: Announcement: National WES case study #15 Greetings All, I am pleased to announce another new addition to the National Case Study Library: National WES case study #15 Title : Southeast Texas Squall Line Author : Lance Wood and Kent Prochazka Localization: HGX (Houston/Galveston, TX) SIMULATION SUMMARY The severe weather that occurred across southeast Texas on 23 December 2002 was a protracted event with isolated severe weather occurring throughout the day. This case begins during the evening hours of 23 December (LST) with the evolution of a severe squall line and pronounced bow echo moving along Interstate 10. The bow echo produces widespread wind damage north and south of the interstate within the Houston metropolitan area. Straight-line winds near 70 mph were estimated from damage reports and radar signatures. The two hour window selected for the simulation is challeng- ing because in addition to the squall line, isolated strong to severe thunderstorms develop ahead of the line and need to be monitored closely, with large hail the primary threat. As the squall line moves into the Houston metropolitan area, mesocyclone and TVS alerts along the edge and in the comma head portion of the bow complicate the warning process, as tornadoes are now a possibility. The warning forecaster must decide whether to upgrade the severe thunderstorm warnings to tornado warnings. The speed and character of this event demand Warngen proficiency. Therefore, in addition to warning decision- making practice, this case is excellent for general WarnGen proficiency training. Due to the large number of warnings and decisions required, this exercise is also good for a pair of forecasters. An experienced forecaster could be teamed up with a less experienced forecaster to provide guidance and to aid with keeping track of warning expiration times. Case #15 is available on DVD along with a companion simulation guide from the SOO/STRC National Case Study Library: http://strc.comet.ucar.edu/csl Let me know if you have any questions. Regards, Bob +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Robert A. Rozumalski NWS National SOO Science and Training Resource Coordinator COMET/UCAR PO Box 3000 Phone: 303.497.8356 Boulder, CO 80307-3000 FAX: 303.497.8491 SOO/STRC Home Page: http://strc.comet.ucar.edu +++++++++++++++++++++++++++++++++++++++++++++++++++++++++