The South Florida chapter of the American Immigration Lawyers Association (AILA) has inquired as to how the Miami District Office of the U.S. Citizenship and Immigration Services (USCIS) will handle airline passengers on Visa Waiver with expiring I-94 Arrival/Departure Records who cannot leave the U.S. on time because they are stranded  due to flights grounded by the volcanic ash over Europe.  

The local USCIS offices intend to grant Satisfactory Departure or "SD" for 30 days to stranded travelers on Visa Waiver, who normally have 90 days to remain in the U.S. Individuals in this situation should make an InfoPass appointment at https://infopass.uscis.gov/info_en.php. If no appointments are available, the local USCIS offices will take walk-ins on an emergency basis.  The individuals should bring their passport and green I-94 card and ask to speak with a supervisor so that they can be assisted.  The person’s I-94 will be annotated with “Satisfactory Departure granted until (dd/mm/yy)".  

When the individual turns in the I-94 upon departure from the U.S., the annotation will be inputted into the computer system and the person is not considered to have overstayed so long as they depart within the extended time authorized.  It is advised that travelers make a copy of the front and back of their I-94 for their records prior to them departing the U.S.

Note that all other visitors in the U.S. with tourist (B-1/B-2) visas whose I-94 period of stay is expiring and who can't leave due to the volcanic ash must file Form I-539 with USCIS to extend their stay in order to legally remain past their I-94 date. The form must be received by USCIS prior to or on the I-94 expiration date and extensions can be granted for up to 6 months. The act of filing timely - and not the approval itself - keeps the applicant in valid status while the application is pending.