American Meteorological Society / National Weather Association
Memphis, TN Chapter
Meeting Minutes

31 March 2009

The March 2009 meeting of the Memphis, TN chapter of the American Meteorological Society/National Weather Association took place at 7:00 PM on Tuesday, March 31, in the National Weather Service Conference Room at Agricenter International. There were about 14 people in attendance.

President Erik Proseus opened the meeting with several topics of business.  This meeting was the last opportunity for members to make donations to the memorial funds for Richard (Ric) Coleman and Brian Teigland, both outstanding gentlemen that had been a part of the Memphis weather community for many years.  The chapter continues to await official word from the National Weather Association of our approval as an NWA chapter.  Erik made mention of our chapter store at CafePress (http://www.cafepress.com/amsnwamemphis) – proceeds benefit the chapter.  We are still searching for possible opportunities to be involved in the educational community in Shelby County and solicit anyone’s input into how our chapter might be able to further our goal to support science in the school system.  We will also be exploring the possibility of using videoconferencing and web-meetings with other area chapters or potential speakers at future meetings.  Using technology could help reduce the cost of bringing speakers to Memphis and make it easier to come up with meeting topics if we were able to piggyback on another chapter’s speaker.  We would of course be open to providing other chapters with the chance to participate in our meetings as well.  Our next lunch meeting will be April 14, 2009 at CiCi’s Pizza in Cordova.

Our presenter for the evening was Journeyman Forecaster Jonathan Howell of NWS-Memphis who gave a presentation entitled “Extratropical Transition of Hurricane Ike and Resultant Mid-South Damaging Wind Event.”  Joseph Lowery, NWS-Memphis lead forecaster, was co-author of this paper that was prepared for the Southeast Severe Storms Conference at Mississippi State University.  Hurricane Ike made landfall in the wee hours of the morning on September 13, 2008 near Galveston, TX as a strong category II storm.  The impacts on the NWS-Memphis (MEG) County Warning Area (CWA) were felt on September 14.  Those impacts included high wind over the northwestern portion of the CWA (northeast AR, MO bootheel, and northwest TN), with sustained wind at 25-45 mph and gusts to 70 mph.  There was one fatality and three injuries associated with the storm in the MEG CWA as the storm transitioned to extratropical status over AR as it moved northeast.

Jon described the stages of extratropical transition and how very high surface pressure changes contribute to a damaging wind threat.  In this particular case, mixing was limited, as was precipitation due to strong subsidence.  Ike transitioned as it interacted with an approaching mid-level trough and strengthening baroclinic zone.  A saturated adiabatic lapse rate below the subsidence inversion likely limited the downward momentum, thereby limiting some of the wind transfer from aloft, or the wind at the surface could have been even higher.  In summary, this event was highly anomalous for the Mid-South region, which makes it difficult to forecast owing to a lack of experience on the part of the forecasters.

We thank Jon for his excellent and informative presentation.

Respectfully Submitted,
Erik Proseus, President