Summer hasn't been very sunny for amusement park operator Six Flags ( PKS). The New York-based company said cool weather in the Northeast and a sharp attendance drop in the second half of June punished first-half numbers. The company said systemwide attendance fell 4.1% in the first half, driving a 1% drop in revenue. The company forecast first-half revenue of $401 million, which is far short of the Wall Street estimate of around $425 million. The weak attendance is hurting cash flow, too. Six Flags said it expects modified earnings before interest, taxes, depreciation and amortization to fall to $30 million in the latest first half from $41.8 million a year earlier. Adjusted EBITDA will fall even more sharply, dropping to $11.5 million from $25.5 million a year ago. "The attendance shortfalls we have experienced have been offset somewhat by very strong per capita spending growth through June 30," CEO Kieran Burke said. "We have seen improved performance since the end of June, with performance since June 30 reflecting attendance in line with prior year, a per capita spending increase of 0.8% and a revenue increase of 0.5% in the period from July 1 through July 13." The company said it expects to remain in compliance with all covenants in its credit agreements and to continue to have "substantial liquidity and no near-term debt maturities." The stock rose 14 cents Thursday to $6.32.