Update, 12:15 p.m. Thursday:
Despite clear skies Thursday morning in the Anchorage area, forecasters were still predicting that clouds would roll in throughout Thursday afternoon.
"We're not quite there yet," said meteorologist Tom Pepe.
Pepe said forecasters expect heavy rainfall and showers, with a slight chance of thunderstorms, from Thursday evening to Friday morning.
Original story:
Heavy and "unusually widespread" rain is predicted to pummel Southcentral Alaska between Thursday afternoon and Friday morning, weather forecasters say, triggering warnings of heavy rain pooling on roadways and rising water in rivers and streams.
While no major flooding is forecast as the Fourth of July weekend starts, the National Weather Service said in a special weather statement Wednesday that the Matanuska River may rise to its highest levels of the summer. Other rivers to the north of Anchorage are expected to see a "significant" rise in water levels, the agency said.
The most rainfall is predicted for the Copper River Basin and the Matanuska and Susitna valleys. "Lesser but still noteworthy" rainfall and river rises were predicted for Anchorage and the northern Kenai Peninsula, the weather service said. Drivers and cyclists in the Anchorage area should expect to encounter pooling water on roadways and bike paths.
The storm is coming just ahead of the July Fourth weekend, a major travel period in the state for tourists and residents.
"As you venture into the outdoors over the Independence Day weekend be aware of your surroundings and any streams, rivers, or bodies of water that may be affected by heavy rains," forecasters wrote.
"Don't attempt to cross flooded roadways," the forecasters warned, "you don't know the condition of the road under the water. Turn around. Don't drown."
Anchorage meteorologist Michael Kutz said the heavy rain is expected to continue through Friday morning before petering off. He said there will be a chance of showers to light rain through the weekend.