The Iceland volcano disruption is causing unprecedented disruptions in air travel all around the world – but your problems could become even worse if you are here in the United States on any kind of Visa or Visa Waiver that is about to expire.
The Visa Waiver program allows you to be here for 90 days – and overstaying that period will result in all kinds of hassles if you ever plan to return. I have personally witnessed someone being sent back to Europe because they had overstayed by 3 days several years ago.
There is no blanket exception for travelers impacted by the flight cancellations, so you are on your own to apply for an extension. Do not assume everything will be alright – even one day past your 90 days can result in a future deportation or entry refusal.
To apply for the extension, you will need to contact a local U.S. Citizenship and Immigration Services facility. A guide on how to extend your visa status can be found here. Even though the normal procedures do not permit Visa Waiver status to be changed, exceptions are being made for people stranded due to the volcano. If you are not able to contact a local office, make sure you have a copy of your I-94 arrival-departure form, as you’ll probably have to put together a letter once you get back home.
The official statement sent to foreign embassies in the U.S. can be found here. I recommend printing this information for future reference.