In a mixed blessing, so much Bertha rain is occurring over Puerto Rico that Flash Flood Warnings are already going up.

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
THE FOLLOWING MUNICIPALITIES

IN PUERTO RICO
CANOVANAS
CEIBA
NAGUABO
FAJARDO
LUQUILLO
RIO GRANDE

* UNTIL 1245 PM AST

As of 10 AM EDT, Bertha may or may not be devolving into a wet and windy open wave. A careful analysis of cloud, precip, ocean wave and wind data does suggest this as a strong possibility. It is also noteworthy that the strongest thunderstorms have been located about 100 miles to the SSE of Ponce, P.R., and within this cluster a mid-level rotation may be attempting to work its way to the surface, which might help reposition Bertha somewhat south and a little east of her extrapolated coordinates.

If either situation, or both, verifies (open wave/center relocation to the south), Bertha could end up tracking further west than presently forecast.