A<em> "faulty parallel structure" </em>refers to an<u> error in the structure of the sentence</u> when it comes to "parallelism." For example, if you used gerunds for some items in your sentence, you have to use it for all the other items in order for them to be parallel with each other.
fair weather consists of the<em> adjective</em> (fair) describing the<em> noun</em> <em>(weather); </em>warm temperatures consists of the <em>adjective</em> (warm) describing the<em> noun </em>(temperatures); however, sunshine is a <em>noun </em>and "to rain" is an<em> infinitive. </em>Clearly, the structure in the sentence shows no parallelism or is a faulty parallel structure.
