Drivetrain Transmission Slips When Cold...help

Hi guys, asking for some help on this issue. I have an 07 GT with an automatic tranny. It seems like this only occurs when it is cold. If I let the car warm up then drive up to a stop sign and stop, as I want to pull away its like the transmission is in neutral until it decides to grab. Also while its cold still if i go around a curve and then begin to accelerate out of it it does this again. I have also noticed when I pull up to a stop light and have to hit the brakes hard and stop its like its in neutral again??? I wish I could check the fluid level. The weird thing is that it seems like after the trans is up to temp it doesnt do this. The car has 85k on it. Any help or guidance would be appreciated. Thanks

Thank you Pete, Ill have to pay attention to it more. But yes it seems like its just dropped in gear and lunges. Weird thing is going around sharp curves and it feels like that also. Like I said it seems to only do it when its cold outside. I live in Ohio and the times i noticed the air temp was 20 or below. Its been 60s and 70s lately with no issues. I appreciate your answer. Ill repost if i notice any changes.