Friday, 28 October 2005
Alvarado F and Atria (Hotel Albuquerque at Old Town)
Multi-Doppler radar, three-dimensional VHF-based lightning, and balloon-borne electric field sounding data from a Mesoscale Convective System (MCS) on 19 June 2004 during the Thunderstorm Electrification and Lightning Experiment (TELEX) are analyzed. The MCS is characterized by a symmetric leading convective line and trailing stratiform region. A significant fraction of the MCS life-cycle was observed by the Oklahoma Lightning Mapping Array (OK LMA) and by a pair of SMART (Shared Mobile Atmospheric Research and Teaching) C-band Doppler radars. The mobile radars were deployed with a 46 km baseline that was oriented roughly parallel to the convective line (i.e., northwest-to-southeast). This paper focuses on the kinematic (e.g., updraft width and intensity, and mass flux), total lightning (e.g., flash rate and height), and in-situ electric field and inferred charge properties of the convective line during the time period from 1252 to 1312 UTC when it experienced a rapid weakening phase. During the weakening phase, the total lightning flash rate in the convective line decreased by nearly a factor of two. Simultaneously, the mean area-averaged radar reflectivity in the convective line decreased dramatically (several dBZ) at mid-levels. It is hypothesized that a rapid weakening in the mid-level convective updraft and associated mass flux resulted in a decrease in the conditions favorable for precipitation ice growth via riming and cloud electrification via the non-inductive charging (NIC) mechanism. OK LMA inferred lightning heights will also be explored as an indicator of convective intensity during this weakening phase by comparing them with the evolution of updraft strength.
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner