With the two most recent eruptions of Mt. Redoubt ash has fallen onto Homer and expected to be in the atmosphere over Anchorage. although according to ADN.com ash wont touch down on Anchorage, but i would suggest to buy masks anyways. with the ash hoovering over the city theres still a possibility small amounts of ash can touch ground, so you can still breathe it in. get a mask to be safe.
for anyone traveling in and out of anchorage tonight, sucks to be you. alaska airlines has cancelled all flights in and out of the city until further notice. fedex, era aviations and other services have also cancelled flights in and out of the city.
if the ash does fall onto anchorage life will go on as normal. they arent expecting the amount of ash fall to cancel school or work. so stop crossing your fingers for an extra day off. you're biggest concern may be a light film on your car, but nothing else. there is still no need to freak out. no one needs to stock up on water and batteries. while a mask isnt necessary im just recommending it as a safety precaution.