CIMSS Nearcasting: Predicts the convective development pattern in Central Florida

On Thursday morning, May 17, the CIMSS GOES Sounder Nearcasting model indicated that unstable Ɵ_e lapse rates would persist over Central Florida throughout the morning and into the afternoon.  Lapse rates would remain relatively weak, but unstable, with the nearcasting CAPE indicating values of 750 to 1000 joules per kilogram.  At 1400 UTC the CIMSS nearcast products indicated that a minimum of weak instability would persist into the afternoon across Central Florida, along a line extending SSW to ENE, with stronger gradients N and S of the line.   Coverage was good at this time because the region was relatively cloud free.

At 1900 UTC HWT forecasters detected a developing convective cell north of Lake Okeechobee and a weaker line of convection south of Gainsville.  Convection in Central Florida remained suppressed. Forecasters noticed that the development matched the nearcasted dƟ_e gradients quite well.

Shown below is a 5 1/2-hour nearcast of dƟ_e  and CAPE valid 1930 UTC, May 17, 2012.  Also shown is the verifying GOES visible and radar images.  Nearcasted CAPE values were strongest along the southern gradient which is where the strongest convection formed.  The areas east of Tampa remained devoid of strong convection.