Weekend weather: Cloudy and potentially wet arrival of autumn

When the autumnal equinox arrives at 7:21 a.m. on Thursday to start the fall season, it will be accompanied – fittingly enough – by a cloudy and potentially wet day.

National Weather Service forecasters said there is a good chance that a low pressure system south of the Inland Northwest will circulate remnants of a tropical storm northward into the region on Thursday.

The result could be periods of light rain in the morning and showers later on with highs creeping into the lower 60s.

Precipitation of less than a tenth of an inch is possible in Spokane and Coeur d’Alene, but higher amounts could fall at locations south and southeast of Spokane and mountains of the lower Idaho Panhandle.

Showers could linger into Friday near Lookout Pass.

The source of moisture is a bit of a twist on Inland Northwest weather.

Precipitation is expected to hook around the incoming low and send the tropical moisture northward from Arizona.

Earlier, Hurricane Paine became a tropical storm as it migrated well off the Baja coast of Mexico and into the U.S. southwest.

As Thursday’s low pressure area moves off to the east, it will allow higher air pressure to return to most parts of the region starting on Friday.

Increasing sunshine and rebounding temperatures are expected with highs going from the middle and upper 60s on Friday and Saturday into the lower to middle 70s by Sunday.

The warmup should continue into early next week with highs going from the middle to upper 70s.

Lows during the period are expected to be mainly in the 40s.