Weather 9-11-19

147

The upper level weather system continues to slowly move eastward today as a shortwave ridge sets up for later today. Under sunny skies, afternoon high temperatures will be warmer than yesterday about 2-5 degrees below average, or in the lower to mid-70s for Northcentral Washington.

Thursday we will see 3-6 degrees of warming as the ridge build then pushes through. Expect increasing clouds throughout the day with afternoon highs warming into the lower 80’s.

By Thursday night and Friday an upper level weather system will move into Central British Columbia and bend down the ridge of high pressure. A weakening cold front will also move through the forecast area late Thursday night and through the day on Friday. Moisture again increases with this weather system, but with this front it looks like the best chance of instability remains in Canada. With the incoming weather, southwest winds will be on the increase through the day on Friday with sustained winds 10 to 15 mph and gusts 20 to 30 mph, highs Friday in the mid 70’s.

The flow flattens and becomes westerly Friday night and Saturday. Expect mostly cloudy skies on Saturday with afternoon high temperatures in the mid 70’s.

Weather model guidance indicates that several weak waves will move through the ridge Saturday night, Sunday and Monday with mostly cloudy skies each day with a 30% chance of rain Saturday night, that goes up to a 50% chance on Sunday and then down to a 20% chance of rain on Monday as the storm moves through the Wenatchee Valley. Afternoon high temperatures on Sunday will cool down to the mid 60’s, upper 60’s for Monday and into the lower 70’s on Tuesday.