Scatterometer observations at the ocean surface of wind speed and direction improve the depiction and prediction of storms at sea. These data are especially valuable where observations are otherwise sparse---mostly in the Southern Hemisphere and tropics, but also on occasion in the North Atlantic and North Pacific.

The SeaWinds scatterometer on the QuikScat satellite was launched in July 1999 and it represents a dramatic departure in design from the other scatterometer instruments launched during the past decade (ERS-1,2 and NSCAT). This talk will present the influence of QuikScat data in data assimilation systems both from the NASA Data Assimilation Office (GEOS-3) and from NCEP (GDAS). At the conference we will present detailed evaluations of the impact of QuikScat data on analyses and forecasts with each of the above systems.