DAYTONA BEACH, Fla. -- The expected path of Hurricane Isabel has prompted NASCAR to cancel the on-track activities at Dover International Speedway scheduled for Thursday and Friday.

Cancellations include qualifying for both the Winston Cup and Busch series, as well as the Busch North Series race, none of which will be rescheduled.

The 43-car fields for the Winston Cup and Busch races will be determined by owner championship points, the same as any normal rain situation.

That means Matt Kenseth and Dale Earnhardt Jr. will be at the front of the field in Sunday's MBNA America 400 Cup, while Kevin Harvick and David Green will be on the front row for Saturday's Stacker 200 Busch Series race.

"After listening to the latest forecast regarding projected weather conditions in Delaware and discussing contingency plans with state officials as well as officials at Dover, we felt it best to cancel on-track activities set for Thursday and Friday,'' NASCAR President Mike Helton said Tuesday. "Obviously, these schedule adjustments are based on current weather predictions. We will continue to monitor the situation and, hopefully, no further adjustments will be necessary.''

The Busch cars will get an early morning one-hour practice on Saturday, followed by a 75-minute practice session for the Winston Cup cars. A one-hour final practice for the Cup cars will follow Saturday's 200-mile Busch Series race, which will be run as scheduled, beginning at 1 p.m.

Sunday's schedule remains intact and culminates with the 1 p.m. start of the Winston Cup race, which will be televised live on NBC.