C # regex - something or nothing

I have two types of possible strings for getting information:

<td class="forecast">106.2%</td>

      

        
        
        
      

    

or

<td class="forecast"></td>

      

        
        
        
      

    

And I want to get what is inside, it could be something like a number, or it could be nothing else, not even an empty space.

I have the following regex part:

<td class=\"forecast\">\\s*(.+?)\\s*</td>

      

        
        
        
      

    

It works when there is content inside the HTML cell, but if there is nothing, it gets the next piece of HTML code.

Does anyone know how to solve this?