what is the weather forcast today?

I read one of my Thai friends 's blog..in Thai. She wrote about how to ask in English about the weather.

These are the questions  to ask  when  we want to know about the weather ;


1. What is the weather forecast for today ?

2.What is the weather forecast for tomorrow?

3. What is the weather going to be like tomorrow?


and also if someone ask you the questions above the answer are ;

1.It is going to upper 40 to low 50, partly cloudy, and chance of rain .

2.It will be in the upper 40 to low 50 today, ................................

sometime people say like this ;
What is the temperature gonna be tomorrow?

gonna is slang , not proper English . 
proper English =>going to be

What is the temperature going to be tomorrow?