The National Weather Service (NWS) issues a tornado watch when the weather conditions are favorable for a tornado forming, and a warning means there is an actual tornado. While a tornado watches is present, a warning is issued within minutes of a warning, and it's crucial to prepare for the actual tornado strike. The ideal tornado shelter is a low-level room without any windows and essential essentials like water. The NWS recommends taking shelter immediately when there is a tornado warning. It's also important to charge your phone before the storm hits, as a power surge may occur and your phone can break. The article was powered by Yahoo Scout, which uses AI to generate key points, which may not always match the content of the article.