'Considerable uncertainty as to where the heaviest rain may fall'

'Considerable uncertainty as to where the heaviest rain may fall'

EUGENE, Ore. - Here comes the rain again, and it's bringing company.

Forecasters predict a chance of thunderstorms in the Cascades and points east overnight.

The good news: the southern Willamette Valley will likely be spared

Not so in Oregon's interior east of the Cascades: Brief heavy downpours from thunderstroms add the threat of flash floods to the perils of lightning.

For the southern Willamette Valley, rain could start falling in earnest by Thursday afternoon.

Thursday night, Mother Nature opens the spigot, according to a hazardous weather outlook and special weather statement

"Heavy showers and thunderstorms are expected Thursday, with heavier showers continuing Thursday night," forecasters said. "Some of these storms may produce heavy downpours capable of localized ponding of water on roadways or other minor urban flooding. This can also result in flooding of small streams.

"Excessive rainfall rates can overwhelm storm drainage in urban areas."

The heaviest rain will likely happen overnight Thursday into Friday.

Where that rain will fall remains to be seen.

"There is considerable uncertainty as to where the heaviest rain may fall," forecasters said.

As of Wednesday afternoon, forecasters hazarded these rainfall forecasts:

  • Widespread rainfall amounts of .25 to .5 inches are expected in the northwest Oregon valleys and foothills, with localized amounts in excess of 1 inch in any thunderstorms.
  • Up to 2 inches or slightly more could occur in the southwest Washington Cascades
  • Up to 1.5 inches in the Oregon Cascades.

The lightest amounts are expected south and west of Salem.

Check the latest weather forecast and watch your local TV news for updates