Weekend weather: First big warmup arrives in the Inland Northwest

The first big warm up of the year arrives in the Inland Northwest Thursday, but it isn’t going to hang around long.

Highs are expected to reach the upper 70s to lower 80s at lower elevations on Thursday under a strong system of higher air pressure.

The warmth will continue overnight with a summer-like low in the upper 50s.

However, the high pressure that is bringing the warmth is expected to migrate eastward by Friday, according to the National Weather Service in Spokane.

An incoming low pressure area will approach the region starting late Thursday, opening the door for showers and thunderstorms Thursday evening in the Cascades and on Friday in Eastern Washington and North Idaho.

In Spokane and Coeur d’Alene, the showers are expected after 11 a.m. on Friday.

Highs Friday will continue to be warm with a flow of air from the southwest. Highs should reach the middle 70s.

Flash flooding and debris flows are possible under any heavy thunderstorms in mountain areas, especially on burned scarred slopes.

The showers and thunderstorms will be accompanied by a cold front that could make for breezy and gusty conditions at times.

The warm weather will increase snow melt and trigger rises in the region’s streams. Flooding is not expected in the latest forecasts, but streams will be high.

Temperatures begin to cool down Friday night with a low in the upper 40s.

Highs Saturday and Sunday should be in the upper 50s to lower 60s with lows in the 40s.

A chance of showers will continue through the weekend.

Temperatures are likely to warm up to the upper 60s and 70s starting on Monday with mostly sunny skies as spring reaches its halfway point.

In the mountains, highs will reach the 60s on Thursday and Friday to trigger rapid snow melt, forecasters said.

But then the temperatures drop back to the 50s for highs and 40s for lows.

The mountains will also see a heightened chance of showers on Friday and Saturday.