When boaters hit the water this Labor Day, they can expect to find a couple of changes: temperatures that are slightly lower than the 100-plus-degree record heat of recent weeks and months, and even lower lake levels. And more of the same: little chance of rain.

Lower Colorado River Authority chief meteorologist Bob Rose forecasts a high in the 90s — 90s! — and 10- to 20-mph breezes thanks to Tropical Storm Lee, which appears headed for Louisiana .

Expect highs hovering around 100 degrees today and Sunday. Then, just like clockwork, the holiday that marks the end of summer — at least in the minds of many Americans — will usher in cooler weather for the week, with highs in the mid-90s.

Tropical Storm Lee is not expected to bring needed rain to Central Texas, however.

Currently, Lake Travis sits at 634 feet above sea level, nearly 32 feet below the September average, and the surface water temperature is 90 degrees.

Low lake levels have forced the closure of 10 Lake Travis boat ramps. The last public ramp open is at Mansfield Dam Park , with one lane available. That ramp will also close if the lake drops four more feet.

The low water has exposed hazards such as trees, rocks and sandbars.

"You can be carefree but not careless," said Lower Colorado River Authority spokeswoman Clara Tuma. "Be mindful of obstacles, and be cautious."

Although the river authority anticipates crowds on the waters, Tuma said, it will not be as busy as summer holidays like July Fourth.

Meanwhile, state Parks & Wildlife Department officers and other agencies will be enforcing new laws on the lakes. Under a state law that took effect Thursday, people in a boating accident no longer must file a report with Texas Parks & Wildlife but can simply notify Parks & Wildlife by phone, by email or in person.

Rep. Donna Howard, D-Austin, pushed the legislation to align Texas' statute with federal boating accident reporting requirements. In the past, all accidents causing damage of more than $500 required reporting; now the law reduces the requirement to only accidents of more than $2,000.

Other new boating rules include:

• Anyone younger than 13 operating a vessel greater than 15 horsepower must be supervised by an adult who can legally operate the boat.

• Anyone 18 or older operating a vessel greater than 15 horsepower is required to take a boater education course.

• All vessels, including canoes, kayaks and paddlecrafts, must have life jackets for every person onboard.