LANCAIR PLT DEPARTS VFR AND ENCOUNTERS IMC PRIOR TO RECEIVING IFR CLRNC.

Narrative

I FILED AN INST FLT PLAN. I WAS UNABLE TO RAISE CTR ON THE GND FOR A CLRNC. I DEPARTED VMC AND CONTACTED ZSE AIRBORNE. THEY ASSIGNED A SQUAWK CODE WHICH I ENTERED. SOON THEREAFTER I WAS INADVERTENTLY IMC WHEN CTR ADVISED ME OF TFC DEPARTING RDM. I RPTED I WAS IMC. THEY REQUESTED SPECIFIC POS AND ALT AND THEN ADVISED ME TO RPT REACHING 8000 FT WHICH I DID. I WAS THEN RADAR IDENTED AND CLRED ON COURSE TO MY REQUESTED ALT OF 17000 FT. THIS OCCURRED BECAUSE I HAVE MADE THIS FLT MANY TIMES AND HAVE ALWAYS PICKED UP MY CLRNC AIRBORNE VMC. CONDITIONS AT S07 APPEARED SATISFACTORY TO DO THE SAME ON THIS FLT. CONDITIONS WERE LOWER IN A FEW MI FROM THE ARPT THAN WHEN I DEPARTED RESULTING IN INADVERTENTLY ENTERING IMC BEFORE I HAD A COMPLETE CLRNC. WHEN I RECEIVED THE SQUAWK CODE I WAS NOT ADVISED TO MAINTAIN VFR PENDING FURTHER INSTRUCTIONS. WHEN ADVISED OF THE POTENTIAL TFC I CERTAINLY WANTED CTR TO KNOW IMMEDIATELY I WAS IMC. TO AVOID THIS IN THE FUTURE I WILL GET A PHONE CLRNC ON THE GND WITH A VOID TIME ALLOWING ME TO DEPART IN A CTLED MANNER.