The Office of Personnel Management’s has issued a Handbook On Pay and Leave Benefits For Federal Employees Affected By Severe Weather Emergencies or Other Emergency Situations.
The booklet summarizes pay and leave benefits available to employees who may be prevented from working in an area affected by severe weather emergencies or other emergency situations (including advance payments and evacuation payments), employees required to work in an area affected by severe weather emergencies or other emergency situations, and other pay and leave benefits.
The hanbook is a supplement to other guidance issued by OPM on the Hurricane Katrina emergency. The OPM information is available on the internet at http://www.opm.gov/emergency/Katrina.asp
You can download the OPM booklet in pdf format.