Re: Yes flow...No flow....When flow??????
external clues would be things like actually seeing blooms as you drive around, increased coming and going at the entrances, lots of pollen coming in on the bees, and bees coming in 'heavy' with the abdomens fat and extended.
it does look to me like the foraging picks up a little after a good rain.
it's hard to know without looking in the hive if enough nectar is coming in for the bees to store and process it into honey. some folks use scales to weigh their hives to see if stores are increasing or not.
journaling the growth of a treatment free apiary started in 2010. 20+/- hives