Questions & Answers about הלוואי שירד שלג רק בערב, כשכבר נהיה בבית.
הלוואי is a wish word: if only, I wish, or sometimes hopefully, depending on context.
In this sentence, it introduces a wish about the future: the speaker wants the snow to come only later, in the evening.
The ש־ means that and introduces the clause that expresses the wish.
So הלוואי שירד שלג is literally something like if only that snow would fall.
You may also hear הלוואי ו... in Hebrew. Both patterns exist, but הלוואי ש... is completely natural.
Here it is understood as future: that it will snow / that snow will fall.
Unpointed Hebrew can hide this distinction. The spelling שירד could represent:
- שיָרַד = that fell
- שיֵרֵד = that will fall
In this sentence, because of הלוואי and the rest of the context, the intended reading is the future one: שיֵרֵד.