Hurricane force winds blowing my confidence away

Today was the nitty gritty phase of my training to set a 5K pr: Intervals.
Four sets of 1,000-meters with a rest period of 3:30 in between each interval. The rest period is so you can recover, get your heart rate back to under 75 percent.
It was 65 degrees. Humid. And windy. Very windy. (This is tornado season in Texas, right?)
I probably should have skipped this workout on the weather alone, but off I went.
And I felt good on the first interval, which I completed in 4:13. (A 6:48 minute-mile pace). This was against the wind. I was feeling confident.
So on the second 1,000-meter interval, with the wind, I popped a 4:01 (6:29 pace). That's fast.
But I wasn't feeling too good. I wanted to throw up and my heart rate was still over 85 percent by the time I started the third interval.
And it was against the wind. A quarter-mile in, I was toast. Time was 5:06 (8:14 pace).
I debated whether or not to do the last interval. But since it was with the wind and I had to run that way anyway to get back to my car, I went ahead. And I eeked out a 4:14 (6:50 pace).
I did a short cool down and shuffled my sweaty ass back to the car.
It doesn't take a fool to know I can't keep up a 6:29 pace for an entire 5K. But I think I might be a little faster than a 6:50 pace. Especially if there is little to no wind.
We'll see next Saturday, when I run in the Komen Race for the Cure. My 5K PR, incidentally set at this race two years ago, is 21:09. If I can run 6:50, I'll be close.
Keeping my fingers crossed.
Cheers.