I'll be traveling with a light coat for my trip in late March/early April. It isn't a water resistant-type coat and I'm wondering what everyone else brings in case of rain? I have a travel umbrella, but it's pretty flimsy and want to be prepared in case we get caught in any downpours. I don't want to buy an add'l coat, or travel w/an add'l coat, for that matter. Any suggestions?