Sandra formed as a tropical storm over the southern Pacific Ocean on March 7, 2013, and strengthened into a cyclone two days later. On March 11, the U.S. Navy’s Joint Typhoon Warning Center (JTWC) reported that Sandra was located roughly 350 nautical miles (650 kilometers) northwest of Nouméa, New Caledonia. The storm had maximum sustained winds of 90 knots (165 kilometers per hour) and gusts up to 110 knots (205 kilometers per hour).
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of Sandra on March 10. The eye of the cyclone was located northwest of New Caledonia and west of Vanuatu, and storm clouds spanned hundreds of kilometers.
Sandra had been moving toward the southeast, and the JTWC forecast that the storm would continue in that direction for the next few days, although it was expected to weaken considerably over the next day or so.