The National Aeronautics and Space Administration scatterometer surface wind vectors are used to describe the rapid onset of the Somali Jet throughout the Arabian Sea. In June 1997 the time of Somali Jet onset varied over the Arabian Sea, with June 17--18 the average time. The Somali Jet appeared first in the western Arabian Sea, expanded over 2 weeks to encompass the Arabian Sea, and produced a threefold increase in surface wind convergence in the eastern Arabian Sea. The onset time of the 12 m s-1 isotach preceded by 3--4 days the onset of monsoon rainfall in Goa. For Somali Jet wind speeds above 10 m s-1 the 2 day 1¿¿1¿ sea surface temperature decreased 0.5 ¿C per 1 m s-1 increase in collocated wind speed. The Somali Jet created a north-south distribution of Ekman pumping and suction in the central Arabian Sea to enhance the eastward surface current by 0.1 m s-1. The Somali Jet doubled the southward Ekman transport across the southern boundary of the Arabian Sea. In June 1997, when the most intense El Ni¿o episode of the century was in its onset phase, the southward Ekman transport across the southern boundary of the Arabian Sea was one half that observed since 1992. ¿ 1999 American Geophysical Union