During the period 15 January--15 March 1986 the average frequency and strength of lightning flashes to the earth's surface over the Gulf Stream off the Carolina Coast was greater than that over the adjacent land.

Near the North Carolina coast, in prefrontal situations, the mean number of flashes to the earth's surface per lightning day per grid area (1¿ latitude ¿1¿ longitude) was 20.9 in the vicinity of the Gulf Stream and 4.8 over the adjacent land. In postfrontal situations the corresponding numbers were 18.4 and 8.9. Most (but not all) of the lightning flashes over the Gulf Stream conveyed negative charge to the earth's surface, and the increase in the frequency of lightning over the Gulf Stream was greater for these lightning flashes than for those that carried positive charge to the earth's surface.

The enhancement in lightning activity over the Gulf Stream is attributed to the recurrent convective rainbands that form in this region. ¿ American Geophysical Union 1990