By John S. McClenahen Far exceeding the consensus forecast for a 0.1% increase, The Conference Board's Index of Leading Economic Indicators soared 0.5% in November, according to data released Dec. 19. It was the second consecutive increase in the index. "Should this pattern in the leading index continue, an economic recovery in the first half of next year may be possible," says the New York-based Conference Board, a business research organization. Six of the 10 indicators that make up the index were positive in November: initial unemployment insurance claims, the interest rate spread, stock prices, building permits, money supply and the index of consumer expectations. However, manufacturing hours, manufacturers' new orders for consumer goods and manufacturers' new orders for nondefense capital goods were three of the index's four negative indicators in November. The Index of Leading Indicators now stands at 109.7. In 1996, its base year, the index stood at 100.