  Previous models of the combined growth and migration of protoplanets needed
large ad hoc reduction factors for the type I migration rate as found in the
isothermal approximation. In order to eliminate these factors, a simple
semi-analytical model is presented that incorporates recent results on the
migration of low mass planets in non-isothermal disks. It allows for outward
migration. The model is used to conduct planetary populations synthesis
calculations. Two points with zero torque are found in the disks. Planets
migrate both in- and outward towards these convergence zones. They could be
important for accelerating planetary growth by concentrating matter in one
point. We also find that the updated type I migration models allow the
formation of both close-in low mass planets, but also of giant planets at large
semimajor axes. The problem of too rapid migration is significantly mitigated.
