US Post doesn't know that it snows....

My card was sent by USCIS with priority mail, planned delivery date was December 14, tomorrow. Since couple of days there was no activity at online tracking service and I started to worry.... Just now I received the call from Sunnyvale post office. The guy said that the letter stuck somewhere in Tennessee because of the weather conditions, snow.... And it is already almost impossible to deliver it tomorrow, "probably next week"....
It's not so important now since I have an approval notice. But I find it really ridiculous.

Serezha N., I hope your guess was wrong, it would be too much!!!!!!!