Ski length for fairly tall VERY light 12 year old

Question
Hi,
My son is 5'4" and 85lbs, no, that's not a typo.  He raced on 151cm Atomic GS12 junior skis this year and had no problem carving.  We will probably move him to a 158cm GS ski next year but we have no idea about slalom ski length.  He is unlikely to gain much weight but he will probably grow 2-3" this year - help?

Answer
Dear Darcy --

Slalom skis can be skied much shorter than GS skis, especially by a light skier.  I recommend you have him start the slalom season on his current multi-event ski, and see how he does.  

Ski length should really be dictated by weight and skiing aggressiveness, not by height.  The Atomic 151cm skis should be fine to start the season in slalom unless he gains a lot of weight in addition to his height.

However, I do not recommend a large jump in ski length especially in slalom skis. So go up no more than about 4 centimeters if you do decide to buy longer slalom specific skis.  

Please write back, if you have additional questions.  Good luck to your son.