Verification of convective initiation patterns and coverage

Based upon the results of a nine year convective study for the northern Mid-Atlantic region, a verification study was performed during the summer of 2009 to assess the usefulness of a newly developed conceptual model of convective initiation for use by Kean University and the PHI NWS office. Analysis focused on enhancement of the “early” forecast cycle (as issued prior to 1200 UTC) in an effort to better specify the expected initiation location, timing, and the threat of severe weather. The intent was to provide more specification for point and zone POP forecasts to better meet user needs and to assess any improvement over operational guidance products. This would serve to improve skill scores, particularly when used in a nowcast (or short term 0-3 or 0-6 hour) forecasts. Therefore, several days during the month of July 2009 were selected in which forecasters prepared a map of expected convective initiation location based upon operational procedures and the conceptual model provided. These were assessed by verification analysis through use of observed radar mapping, local WRF output, and in comparison to model guidance products. Results that will be discussed include the relevance of the approach, verification score improvements, and identification of bias or failings of the conceptual model.