U.S. Open: No dry run

Extended weather forecasts can never be fully trusted due to the limits of computer models and the state of the art of weather prediction.

That's particularly true as the weather warms and the temperature contrasts that drive the winds that move weather systems weaken.

But while precise day-to-day conditions may be impossible to nail a week in advance, looking ahead it appears that the Merion Golf Club, which is hosting next week's U.S. Open, could encounter a few weather challenges.

The biggest concern looms this weekend in advance of the tournament, as an area of tropical moisture works its way from the Gulf toward the Northeast. 

The National Hurricane Center has increased the odds that the blob in question grows into Andrea, the first named storm of the season.

Yesterday, it put the chances at 20 percent, now it's up to 30. In any event, it's possible that moisture will interact with a system moving in from the northwest to wring out some decent rains.

The National Weather Service is going to for a strong likelihood of showers Friday night and Saturday, and it's unusual to see 70 percent probabilities so far in advance.

The forecast also calls for a chance of showers on Monday.

One thing appears all but certain: Dryness won't be an issue when the golfers tee off next week.

And on the bright side, temperatures should be quite comfortable -- upper 70s to low 80s -- and no significant heat is in sight.