BAY STREET-Railroad CP on track for revamp although risks remain

* CP stock is up 20 pct since end-June * CP has second highest PE ratio of North American railroads * CEO Harrison to lay out turnaround strategy Dec 4-5 * Harrison targeting big improvement in operating ratio * Economy, weather could hamper turnaround By Nicole Mordant VANCOUVER, Nov 18 (Reuters) - Less than five months into the appointment of a hard-driving chief executive, industry laggard Canadian Pacific Railway Ltd is already showing signs of a turnaround, and inve