Weather 9-15-20

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A weak weather disturbance running to the northeast between a large offshore low-pressure system and an interior high-pressure ridge is bringing some light precipitation, mostly sprinkles, to parts of Washington this morning. Otherwise today, the ridge gets a bit more of a negative tilt and amplifies some as the offshore low digs a bit towards the southwest through Wednesday night. The result of this orientation is a persistent air flow from the south to continue to stream smoke from regional fires into the area with no precipitation expected.

Weather for Northcentral Washington today, mostly cloudy skies and widespread smoke with afternoon highs today in the lower to mid-70’s.

More of the same for Wednesday and a bit warmer, under smoky, hazy skies, high temperatures should top out in the upper 70’ to lower 80’s.

By late in the day on Thursday, the upper level low pressure system that has been sitting over the eastern Pacific will slowly push across the Northwest. Thursday will see little changes from the rest of the week. The region will remain under southerly flow and there is a good chance this will continue to bring additional smoke across Northcentral Washington with afternoon highs Thursday, cooler, down into the mid 70’s.

The southerly flow will also bring warmer temperatures aloft on Thursday and pump moisture into the region for Thursday night into Friday from the low off the coast. We will see a 30% chance of overnight showers Thursday with lows in the mid-60’s.

The Columbia Basin and Wenatchee Valley on Friday can expect mostly cloudy skies and a 60% chance of showers and maybe even a thunderstorm with afternoon highs in the mid-70’s. There could be brief heavy downpours on fresh burn scars and that would be a concern for rapid runoff.

Showers with embedded thunderstorms will continue to be possible into Saturday with best chances shifting off of the Cascades more into extreme eastern Washington and into the Idaho Panhandle. Northcentral Washington can expect a 20% chance of morning sprinkles with skies turning mostly sunny by afternoon with high temperatures in the upper 70’s. The good news is that there will be a better potential of scrubbing out the smoky air heading into Sunday and early next week. Hopefully this low-pressure trough will also squash the fires a bit across the west with its moisture and cooler temperatures.

Quiet weather expected for Monday and Tuesday with mostly sunny skies each day and afternoon high temperatures in the upper 70’s.