BEECH V35 PLT ENCOUNTERS WX AND ICING WHILE ENRTE; PLT REQUESTS MULTIPLE TURNS IN A CLR POCKET TO MELT ICE AND CONTINUES WITHOUT INCIDENT.

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I WAS ON AN IFR FLT PLAN FROM SAC TO OTH (NORTH BEND) AT 10000 FT MSL. I USED DUATS AS MY PREFLT BRIEFING AND CHKED WX AGAIN BEFORE DEP USING FBO WX TERMINALS. THE FLT PLANNER MODULE OF DUATS SUGGESTED THAT TEMPS WOULD BE ABOVE FREEZING ALONG MY RTE. MY PLAN WAS TO FLY FROM SAC TO RBL AND MAKE A DECISION TO LAND AT RBL OR CONTINUE OVER THE MOUNTAINS TO FJS AND OTH. THE WX TO RBL WAS A MIX OF VMC AND IMC; LIGHT CHOP WITH TEMPS HOLDING AROUND +5 DEGS C. I ELECTED TO CONTINUE TO FJS/OTH BASED ON THESE CONDITIONS. PRIOR TO REACHING FJS THE CLOUDS BECAME MORE SOLID OVCST. TEMPS DROPPED SLIGHTLY TO +4 DEGS C BUT I STARTED TO PICK UP ICE (TRACE AT FIRST; THEN THE ACCUMULATION BECAME MORE RAPID). I NOTICED MY AIRSPD START TO DROP AND I NOTIFIED ATC. I THEN REQUESTED A CIRCLING TURN IN AN OPENING IN THE CLOUDS. I WAS ABLE TO REMAIN CLR OF CLOUDS FOR MULTIPLE TURNS AND THE ICE DISSIPATED. I THEN CONTINUED ON COURSE WITH NO FURTHER PROBS. I ASSUME THAT I WAS FLYING THROUGH POCKETS OF COLDER AIR WHICH MY 2 TEMP PROBES WERE UNABLE TO REGISTER QUICKLY ENOUGH. I REALIZED A FEW THINGS AFTER REVIEWING THE FLTS. 1) IMC AND COLLECTING ICE OVER MOUNTAINOUS TERRAIN LEAVES FEW; IF ANY; 'OUTS.' I WILL OPT FOR A MORE FAVORABLE COASTAL RTE WITH LOWER MEA'S NEXT TIME. 2) FLYING CLOSE TO THE FREEZING LEVEL IN IMC CAN RESULT IN UNEXPECTED ICING CONDITIONS. 3) NOTIFYING ATC EARLY IS A GOOD CHOICE.