Upon arrival at the BMW Championship on Thursday morning, three things stuck out immediately: The sun was shining full-bore, the temperatures were way down from the previous day, and there was barely a trace of a wind.
You couldn't help but think if ever there was a day for some low, low scoring at an already-vulnerable Conway Farms layout, this was going to be it.
And when the very first scores posted on the enormous, hand-operated scoreboard in the media room read 3, 3 and 3 -- as in birdie, birdie, birdie -- well, you couldn't help but thinking "here we go."
It took a little longer for Brandt Snedeker to reach that same conclusion, but when he did -- about midway through a string of 7 straight birdies -- the reigning FedExCup champion started thinking big.
Real, real big.
"I didn't really think about it too much until 16," said Snedeker, whose group began their day on the 10th tee. "I made a good birdie on 16, which was playing tough, so I think at that point it was 4 or 5 (birdies) in a row.
"And then on 17, I ended up missing the green on the back fringe, and that putt went in from about 40 feet."
And that's when it really hit him.
"Then I started thinking, 'OK, we've got something going on here,'" said Snedeker, whose 7 birdies in a row ties the BMW Championship/Western Open record set by Hubert Green in 1985. "This is pretty special. This doesn't happen every day."
But then in the early afternoon, the winds picked up out of the north, the temperatures dropped noticeably and, alas, the magic dimmed.
Snedeker managed just 1 more birdie over his final eight holes, but it was still good for an outstanding opening round 63 and a 1-stroke lead over Zach Johnson after the first day of play in front of a sold-out house in Lake Forest.
A potent four-pack of players -- Steve Stricker, Tiger Woods, Wheaton's Kevin Streelman and Charl Schwartzel -- sit tied for third place, just 3 strokes off the lead at 5-under.
Not quite the number many expected when the day began, but the ever-changing weather will do that.
"When I teed off, the first five holes it was pretty calm and then all of a sudden it picked up and got quite strong," Schwartzel said. "It wasn't just from one direction; it kept switching around.
"If you had putts that were crosswind, it definitely affected those rolls."
As well as Snedeker and his nearest pursuers shot Thursday, the fact is that an awful lot of players (32) were over par for the round, including Rory McIlroy at plus-7 and Lee Westwood at plus-9.
And in between the really great and really bad scores were guys like Phil Mickelson, who battled back from a rough start with 3 late birdies to finish with a solid 70.
"I think there's some really, really tough holes and some really good birdie holes, that's exactly it," Mickelson said. "There's a good mixture of really hard holes and really good birdie opportunities. That's why we have such a discrepancy in scores.
"Guys that play well can make a number of birdies and pars on the tough holes, and if you're not playing well you're not making birdies and you're making some bogeys, and we have a huge difference between the leaders and the guys back."
Having seen a lot of good and a lot of bad in the opening round, what would one expect when they arrive at the course Friday?
For Johnson, whose bogey-free round of 64 equaled his best of the season, it will all be in the hands of Mother Nature.
"I think the numbers are going to be completely indicative as to what the weather does," Johnson said. "The temperatures are going to drop, so the ball is not going to go as far.
"If the wind stays this potent and potentially out of this direction, you know, it's not going to be that easy."