This exception to the early distribution penalty only applies to specified disaster areas. Per the instructions for Form 8915A, to qualify for this exception your main home must have been located in a listed disaster area at any time during 2016 and you must have sustained an economic loss because of the disaster.
You can file the 8915A with your 2017 tax return. Keep some documentation about the loss of your trees and siding to back up your claim that you were adversely affected by the disaster just in case the IRS ever challenges your claim.
Amendments might come into play if you decided to repay any of your qualified disaster distribution. For details, see Amending 2017 Form 8915A in the instructions for the form.
It would be nice if the instructions for Form 8915A were clearer so I could give you a definitive answer. If you sustained economic damage from storms in Iowa within the timeframe shown in Table 1 of said instructions one would think that you'd be all set.