You use this form in sentences that include a time expression, like tomorrow or next week.
Es regnet It's raining
Morgen regnet es. Tomorrow it's going to rain.
Die Sonne scheint. The sun's shining.
Morgen scheint die Sonne. Tomorrow the sun's going to shine.
Es schneit. It's snowing.
N鋍hste Woche schneit es. It's going to snow next week.