UNSEASONABLY HOT AND MUGGY FRIDAY AND SATURDAY FOLLOWED BY STRONG TO SEVERE THUNDERSTORMS SATURDAY AFTERNOON AND EVENING.
The overall pattern is an unusual one with a very warm airmass in place along with a very moist upper level atmosphere. Friday and Saturday are expected to be near 200% or more of normal precipitable water. Combine that with near record temperatures in the low to mid 90s and it will feel rather muggy both Friday and Saturday. The main driving weather force is a cutoff low southwest of California. A much larger north Pacific area of low pressure is meandering over the Gulf of Alaska. The combination of these two areas of low-pressure, places the Pacific Northwest in a southwesterly flow aloft as our upper ridge of high-pressure slides to the east.
Before all of that potential severe weather, today Northcentral Washington can expect sunny skies with some high, thin clouds and hot afternoon temperatures with highs in the lower to mid-90’s.
The potent weather system then begins to move our direction from the south on Saturday with increasing clouds throughout the morning and then a 30% chance of showers and thunderstorms by afternoon, windy too out of the northwest 10-20 mph, highs right around 90 degrees.
Then by Saturday night, showers and thunderstorms will become widespread along with gusty winds over much of the Inland Northwest. The Columbia Basin and Wenatchee Valley have an 80% chance of heavy downpours of rain and possibly severe thunderstorms with large hail and damaging winds. With severe weather, the hazards of frequent lightning, brief heavy downpours, large hail, and damaging winds can result in a host of impacts. Thankfully it is still very early in the fire season so fuels may not be receptive to the lightning. Lightning caused fires are possible but with the green fuels and abundant rain accompanying the lightning, large wildfires are not a concern at this time. Also, rain rates could produce localized flooding or if enough rain falls on a recent burn scar, flash flooding or debris flows are possible.
As the strong weather system pulls away from the area on Sunday we could still see a lingering morning shower with mostly sunny conditions by afternoon, still breezy and cooler with afternoon highs around 70 degrees.
Our weather forecast stabilizes beginning on Monday and continuing through the week with mostly sunny skies each day and afternoon high temperatures warming into the upper 70’s on Monday with the lower 80’s expected on Tuesday, Wednesday and Thursday.