EUGENE, Ore. - Whether or not the southern Willamette Valley gets coated in freezing rain depends on how quickly the temperature rises.
Forecasters had called for temperatures above freezing Wednesday, but the Eugene Airport only got up to 29F.
For Thursday, the airport is forecast to hit 34F and then stay just above freezing overnight.
What hangs in the balance: the intensity and duration of a freezing rain event.
"We are still in a tough forecast spot with regard to which areas will see rain or freezing rain," the National Weather Service said on its Facebook page Thursday morning. "Our recommendation is to keep an eye on the air temperature using an actual thermometer and not your phone's weather display. If it starts raining and the temperature is near or below freezing, then assume surfaces will become icy.
"Fortunately, this still looks like a relatively short event for most, if not all, areas."
Forecasters say they have increasing confidence that the southern Willamette Valley will see freezing rain Thursday afternoon. The slight risk mentioned earlier this week is now backed by "moderate" confidence.
So it's not a sure thing.
But the National Weather Service issued a Winter Weather Advisory for the area, in effect from 1 p.m. to 7 p.m.
"Areas of freezing rain may develop mid to late this afternoon and persist into early this evening," forecasters said. "If the temperatures warm several degrees above freezing early this afternoon, then the threat likely no longer exists except in the most sheltered locations."
Freezing rain would cause a layer of ice to form on roads and sidewalks, making travel treacherous.
The ice - and remaining snow - should started melting this evening as temperatures warm above freezing, forecasters said.
That brings with it another set of hazards.
"Low-clearance vehicles will risk becoming high centered when currently snow packed roads soften and turn slushy this evening," forecasters said Thursday morning. "In addition, traction can be an issue in these conditions and it is easy to lose control of a vehicle."