Hey there, Nosky...good to see you
It goes even farther inland in NW Indiana because we get wind blowing directly off of the lake all winter. It takes longer for the ground to heat up because of it. That's why Lake, Porter, and La Porte counties can be so finicky.
Blacks are genetically identical to half-frees, greys, and yellows. They're black because they need to absorb more light to compensate for the colder ground.
I start to search for them when the ground temp is in the low 40's, and leaves are budding. With all others, I look for partial shade...early in the season, blacks tend to pop where there's more constant sunlight, and colder/darker pockets later. When I am searching for them, I start on the SE side of the forest working west, and hit most any sunny hill or open patch I can find. They are tough, but once you figure them out in a forest, you're golden for the entire season. If I find a patch, I tend to find more (peckers/greys/yellows) later to the north and west of where I found the blacks.
BTW, not sure why, but I have the best luck with black morels near Ash trees. Maybe they wake up faster than other species...I don't know