The running of the 2012 Daytona 500 has been postponed to Monday, after intermittent heavy rainfall in the vicinity of Daytona International Speedway in Florida.
Light rain started just before 11.30am local time, two hours before the race was due to start. Driver introductions, invocations and the national anthem went ahead as scheduled, but even as the pre-race ceremonies were underway the skies opened with the first of a series of heavy pulses of rain that left the track and the infield awash with water.
The rain had eased up and even briefly stopped on a number of occasions, with the jet dryers ushered out to start the track drying as soon as possible, but the heavy rain then returned at 5pm ET (10pm GMT) and radar showed that further significant rain was moving into the area and would likely last for several hours.
"It's one of those days here in Daytona where it pops up and falls off and pops up and falls off," summarised NASCAR president Mike Helton.
With the light fading, the estimated time for drying off the track after dark rose to between three and four hours. That meant that once rain finally ceased there would be little chance of getting the race started before 10pm local time.
That forced NASCAR's hand, and the official announcement was made that the start of the race was now postponed until noon on Monday. All spectator tickets from today's event will be honoured tomorrow, NASCAR confirmed.
It is the first time in the history of the Daytona 500 that the race has been forced to postpone to Monday, although the race has had to be shortened on four occasions because of the weather in the past - most recently in 2009.
The rain is expected to lessen overnight, but the forecast for tomorrow during the day is much the same and if anything worse than the conditions that the Speedway has been facing on Sunday. Chances of rain at noon tomorrow are put at 70%.
The outlook does significantly pick up late in the afternoon and into the evening, raising the prospect of a Monday evening Daytona 500 in US TV prime time from around 7pm ET (midnight GMT).