TITLE: GCN CIRCULAR NUMBER: 19337 SUBJECT: GRB 160424A: Swift/UVOT Upper Limit DATE: 16/04/24 14:06:06 GMT FROM: Frank Marshall at GSFC F.E. Marshall (NASA/GSFC) and A. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team: UVOT took a finding chart exposure of 150 seconds with the White filter starting 3059 seconds after the BAT trigger (Lien et al. GCN Circ. 19335). No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error region (Evans et al. GCN Circ 19336). Sensitivity is less than usual because of reduced pointing stability. We estimate an upper limit of 16th mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.