CI continued along the dryline in eastern Oklahoma into southern Kansas continued for several hours on the afternoon of 19 May 2011. The SATCAST CI Nowcasting algorithm provided ~15-45 min lead times for the occurrence of 35 dBZ echoes with several storms. With the lack of cirrus clouds, individual cumulus clouds could be monitored as they developed into (at times) long-lived supercells which produced tornadoes.
Shown is the SATCAST CI nowcast at 2002 UTC (top image, with 2000 UTC surface observations), with the dryline and four CI locations highlighted. Also, a 4-panel radar image set (from 2018-2100 UTC) with the actual CI locations shown, with approximate lead times on CI provided, as subjectively determined. HWT forecasters found these nowcasts valuable as they were able to determine quickly that CI along the dryline was continuing and would be for the coming ~1 hour past the nowcast time of 2002 UTC. The environment on this day was accompanied by ~2500-2700 Jkg^-1 CAPE values, especially in areas further south along the dryline into far northern Texas. The high CAPE values imply a lower lead time on CI in general, as cumulus clouds grow very rapidly between 15-min time resolution images. Having 5-min GOES data will substantially improve our ability to provide more timely CI nowcasts.
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