89th American Meteorological Society Annual Meeting

Wednesday, 14 January 2009
Ongoing enhancements to satellite nowcasting of 0-1 hour convective initiation
Hall 5 (Phoenix Convention Center)
John R. Mecikalski, University of Alabama, Huntsville, AL; and W. M. MacKenzie Jr., J. R. Walker, and C. Siewert
This presentation highlights the recent improvements in the 0-1 h forecasting (“nowcasting”) of the initiation of thunderstorms. The goals for accurate high-temporal convective initiation (CI) forecasting has resulted in improvements to the Mecikalski and Bedka (2006; hereafter called the “SATCAST”) GOES-based CI nowcasting methodology, which has subsequently broadened our understanding of how GOES senses growing cumulus clouds. Convective initiation is defined here as a transition from below to above 35 dBZ echoes as observed by radar.

Recent work to: 1) demonstrate and describe the absolute skill in our GOES-based procedures in terms of Probability Of Detection (POD) and False Alarm Rate (FAR) scores, 2) present a more complete understanding of the relative importance of each possible GOES infrared field to nowcasting CI, 3) develop alternatives to cloud tracking procedures, and 4) to highlight the benefit new and existing satellite data will have to this nowcasting, will be highlighted. Details will be provided on the validation work recently done on SATCAST, how this validation work can be improved via “object tracking” approaches to identifying convective clouds in satellite imagery, and how additional interest fields will add value to those provided by GOES. New research on the use of the 3.9 um channel will also be provided, which allows for nighttime CI and lightning initiation nowcasting to be performed.

Through research involving the “Corridor Integrated Weather Systems” (CIWS) we are fortunate to be able to test these improvements within a methodology to nowcast CI. Work already completed shows that GOES information from moving convection has value above that previously used within this system. This presentation will report on our progress and most recent findings. Other transition activities in the NOAA Algorithm Working Group, within Central America, and for EUMETSAT, will be discussed.

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