Image Source How to build a rainy day budget: Many Americans know the importance of building an emergency fund, but few are able to do so successfully. Research from the AARP found that 53% of American households lacked an emergency savings account.  Not only are Americans unprepared for emergency expenses, but most households would struggle with an unexpected $400 expense, according to the Federal Reserve. These findings indicate that few people have invested in either a rainy day budget or an emergency fund, relying instead on loans and credit card debt when unplanned expenses pop up.  It doesn’t have to be painful to build a rainy day budget or an…