Temperatures will fall to well below freezing on Wednesday night in the Tri-Cities, according to the National Weather Service.
Lows could drop to as cold as 25 degrees, possibly damaging outdoor plants and underground sprinkler systems, and then warm to just at freezing Thursday night.
Some snow — less than an inch — could fall south of the Tri-Cities in the Horse Heaven Hills by noon Wednesday.
If you’re planning to drive to the west side of the state or to the mountains, expect possible rain or snow.
Precipitation could fall as snow at elevations as low as 1,000 feet in the Blue Mountains, according to the weather service.
A winter weather advisory was issued Tuesday for the Cascade Mountains above 3,000 feet.
The main concern is additional snow of up to 5 inches at Stevens Pass.
Snow also fell on Snoqualmie Pass Tuesday, with traction tires advised. Weather was expected to clear there on Wednesday.
Cold could set record
Usual lows for early October in the Tri-Cities are in the low to mid 40s.
The cold air could bring the potential for record low temperatures in Eastern Washington.
Highs will fall to about 55 on both Wednesday and Thursday as skies clear, according to the weather service forecast.
Low temperatures could kill crops and other sensitive plants and could damage unprotected plumbing.
It is time to drain in-ground sprinkler systems.
To help prevent freezing and possible bursting of outdoor water pipes that have not yet been drained, they can be allowed to drip slowly.
The Kennewick Irrigation District announced it will stop water delivery on Thursday, Oct. 10.
The weather service has predicted a colder than normal October for the Tri-Cities.