Negating Logical Expressions: An Example

Here we are given a statement in English: "In New York, if it is winter and there is high pressure in the north, the weather is extremely cold but the sky is clear."

We are asked to convert this into logical symbols, and then to use this to formulate the negation of the statement.

In a way this is like finding the opposite of the statement, but transforming the statement into logical symbols makes it much clear how to form the negation.