The Nikkei stock index briefly surged over 3 percent Friday morning, as stronger-than-expected U.S. retail sales data eased concerns over the world’s largest economy, while a weaker yen boosted export-oriented issues. The 225-issue Nikkei Stock Average ended the morning session up 1,073.78 points, or 2.92 percent, from Thursday at 37,800.42. The broader Topix index was up 62.63 points, or 2.41 percent, at 2,663.38. The U.S. dollar fell slightly to the upper 148 yen level in Tokyo after climbing 2 yen in New York, as the U.S. retail sales data intensified speculation that any interest rate cut …