Bees leaving the hive and dying
Just started beekeeping last spring. I live in Northen US and we had a snow storm last week but today hit almost 60. I noticed both my hives had decent activity coming in and out. I checked at the end of the day today and I saw a bunch of dead bees around the hive in like a 15 ft circle that weren't there this morning. These aren't removed from the bottom board right at the entrance. I even saw several bees flying and then crashing into the snow. Sometimes they got up sometimes they didn't. Most bees leaving and entering the hive seem fine. I cracked open the top covers quickly and found a decent amount on the frames and plenty of capped honey still in there. Not sure if it's normal and these are just natural deaths happening outside the hive after a long winter or if something is wrong.
On a side note, before I cracked open the top I was afraid they didn't have any food so I put syrup water on my front feeders but after doing research I learned that may not be a good thing to do. Since I saw stored honey, should I pull the syrup water or is 45-60 degrees during the day and 30-40 at night warm enough to keep the sugar water on?