The Merit Systems Protection Board said today it will grant deadline extensions to people who couldn’t file documents on time because of recent blizzards and government closures in Washington and other areas. MSPB Chairwoman Susan Grundmann said anyone filing a late petition for appeal, petition for review, case-related documents, pleading or other submissions will have to include a statement explaining that the delay was due to poor weather, closure of a federal office, or lack of access to MSPB’s e-Appeal Online Web page. That last part is important, because there were tens of thousands of people in the Washington area who…