Wal-Mart is lowering its sales forecast for August. The company is citing the rollback on Hurricane Charley`s swipe across Florida and slower than expected back-to-school sales. Wal-Mart closed about 75 stores after Hurricane Charley cut a path across Florida on August 13th. The company reported good sales before the storm, but up to 200 stores were impacted by the high winds and rain. The world`s largest retailer had previously expected same-store sales to grow between two percent and four percent during the month. It advised Monday that the sales will range from flat to up two percent. Wal-Mart also said that its back-to-school sales were not hitting company targets.