 Upon becoming a tropical cyclone, the depression was stationary in an area with warm sea surface temperatures, very light wind shear, and favorable upper-level conditions.In the hours after becoming a tropical cyclone, the deep convection associated with the depression decreased, though it again increased later in the day.A ragged rainband developed in the southeastern quadrant of the circulation, and based on increased Dvorak numbers and improved presentation on satellite imagery, the National Hurricane Center upgraded the depression to Tropical Storm Barbara on May 30 while it was located about 115 miles (185 km) south of Puerto Escondido.