P1.14
Environments of bow echoes associated with localized vs. widespread straight-line wind damage
Amber E. Reynolds, NCAR, State College, PA
One of the more significant forms of mesoscale convective organization is the bow echo. Although bow-shaped convective lines are relatively small in scale (20 – 120 km long), they can produce damaging straight-line winds over periods of several hours across swaths of several hundred kilometers. Bow echoes represent a challenge for operational forecasting and warning of severe weather. It is difficult to predict the severity of these systems, which often results in false severe weather warnings issued to the public. The environments of bow echoes associated with localized vs. widespread straight-line wind damage were analyzed and contrasted using data collected during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX). Two cases were selected to represent both the localized and widespread straight-line wind damage scenarios. Most Unstable (MU) and Mixed Layer (ML) Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) were computed from environmental soundings. Bulk wind shear was also calculated for surface to 3 km and surface to 6 km intervals for all cases evaluated. The results of this investigation indicated that lower levels of CIN tend to favor systems that produce widespread wind damage. However, in the cases analyzed, vertical wind shear seemed to have no correlation with the severity of bow echo systems, whereas high values of ML CAPE did favor widespread wind damage. Although more cases need to be analyzed, the results of this research may indicate an important method for forecasting widespread wind damage associated with bow echoes.
Poster Session 1, Poster Session
Sunday, 11 January 2004, 5:30 PM-7:00 PM, Room 608/609
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