We enjoyed one more dry and seasonably mild day today. Satellite indicates a deepening and approaching upper level trough moving through western Washington this afternoon…with the speckled nature of the cellular clouds inside of this trough usually indicating a cool and unstable airmass.
This system will overtake the area as this system moves over the forecast area starting tonight and Wednesday. All of the latest weather models indicate the front will generate an area of showers late tonight and early Wednesday morning as it moves over the rising terrain of the eastern basin in Washington. On Wednesday the cool and unstable trough will move over our forecast area…leading to a much cooler day with mostly cloudy skies and a 20-30% chance of showers.
Scattered showers are expected over the mountains with snow levels lowering to the 3000 to 4000 foot level. By Thursday and into early Saturday, the weather pattern change is well underway with a cold conditionally unstable airmass contained in a large trof of low pressure residing over Northcentral Washington. A slow warming trend and drier weather will arrive over the weekend until another fairly large low pressure system moves our way by early next week.