Rainfall amounts for a system that arrives after midnight may have diminished to a forecasted inch or less, forecasters say.
But the heaviest rainfall is expected right at the Thursday morning commute time, in the 6 a.m. to 8 a.m. range, said Joe Pollina, National Weather Service meteorologist based in Upton.
Rainfall, which is expected to be widespread, could be locally higher, especially with any isolated thunderstorms, he said.
In a hazardous weather statement, the service said that "there is potential for 1 inch per hour," but the potential is low "and therefore any flash flooding potential is low."
As much as 2 inches of rain had been earlier forecasted, but Pollina said that the system's track shifted.
Rain may start out "showery" and become "steadier and heavier as the night progresses," turning "moderate to heavy as the rush hour approaches" and decreasing into early Thursday afternoon, he said.
Temperatures Thursday are forecast for the upper 60s, slightly lower for the Twin Forks, "rebounding" Friday to the mid-70s, with upper 60s for the Forks, he said.