AN MD80 AND AN EMB 135 HAVE AN NMAC DURING VECTORING IN PROX OF TSTM ACTIVITY NEAR CLE; OH.

Narrative

AFTER GOING AROUND FROM RWY 24L (WINDSHEAR); WE WERE BEING VECTORED AROUND WX FOR AN EVENTUAL APCH AFTER THE WX PASSED. AT 4000 FT MSL; IN THE CLOUDS AND TURB; A COMMUTER ACFT AT 6000 FT ENCOUNTERED A SEVERE DOWNDRAFT. HE RPTED SEEING 3000 FPM DSCNT RATE ON THE VSI. TCASII ISSUED A TA AND WE RESPONDED ACCORDINGLY. OUR TFC BLIP SHOWED DIRECTLY OVERHEAD AT OUR ALT. CONDITIONS WERE IMC; NO VISIBLE CONTACT WAS MADE. NO RPTED INJURIES WERE MADE FROM THE EVASIVE MANEUVER. SUPPLEMENTAL INFO FROM ACN 529125: FLT XXX TO CLE; EMB 135; APCHED CLE ARPT AS FAST MOVING COLD FRONT WAS APCHING THE AREA; GUSTY WINDS AT 40 TO 60 KTS AT CLE ARPT. OTHER FLT; AN MD80 MISSED DUE TO WINDSHEAR. CREW OF EMB 135 REQUESTED A HOLDING PATTERN. BOTH ACFT WERE VECTORED NE. MD80 WAS AT 3000 FT; WE WERE AT 4000 FT AND REQUESTED 8000 FT. FLT WAS VECTORED 010 DEGS; THEN IN THAT HEADING A CUMULUS CLOUD WAS ENCOUNTERED; SEVERE DOWNDRAFTS WERE EXPERIENCED AND 1000 FT WAS LOST. MD80 ACFT WAS IN THE VICINITY AND AN RA ADVISORY CAME ON TCASII; EVASIVE ACTION WAS APPLIED; THEN UPDRAFT WAS EXPERIENCED AND ACFT CLIMBED TO 6500 FT. SEVERE TSTMS APCHING THE AREA. CTLRS SHOULD ADVISE WELL BEFORE APCHING THE AREA; NOT ENOUGH ALT NOR DIST BETWEEN ACFT WAS PROVIDED; AND COORD WITH AIRLINES ABOUT POTENTIALLY APCHING TSTMS; AND BETTER GUIDANCE TO AVOID TSTMS.