With the Three Lions ahead 2-0 in the five-Test series, Prior said that he would be content with a draw.
"I would be more than happy [if it rained all day]," PA quotes Prior as saying. "If it did then great, but it was meant to start raining at one o'clock today and it didn't. Forecasts in England are pretty good at being wrong.
"It would be very dangerous for us to rely on rain or forecasts going in to tomorrow. We have to steel ourselves tonight and prepare going into tomorrow morning as though we are going to play a full day's Test cricket. We know what is at the end of the line."
He added: "It was dark [when we went off the field]. It's up to the umpires when we come off - they control the game and we do what they say. Certainly for two or three overs there the light had dropped. We've put ourselves in a great position here in this game so far. We've set it up for us to try and take the wickets and win the game. That's all we can control at the moment."
The fourth Test gets underway at the Riverside Ground in Durham on August 9.