Having problems with atof(). (_fragment_)

MPLAB X 3.35.XC32 1.42.PIC32MX570F512L. char rmc_buf[] = "$GNRMC,170341.00,A,4336.24959,N,11622.67799,W,0.527,,031019,,,A*77\r\n";
char *ci;
double lat;
LONG x;

ci = strchr( rmc_buf, 'A' );
ci++;
//lat = ( 60000.0..