Sound to Summit Forecast Memorial Day Weekend
Updated yesterday at 11:51 PM
We're often asked which weeks offer the best weather in western Washington. Typically, the last two weeks of July and the first two weeks of August. Not Memorial Day Weekend...which of course falls well before the official beginning of summer. But this weekend doesn't look bad. Especially the first part!
From the Crows' Nest
A moderately strong ridge of high pressure is building in the upper atmosphere. The flow around that ridge will curl around a low now moving into northern California (as I write this Thursday night). That will produce a dry northeasterly flow, leading to clearing and warming Friday and Saturday. The ridge does show signs in computer projections of beginning to weaken late Saturday, though I don't believe significant cloudcover is likely until overnight Saturday or Sunday.
A weak disturbance will approach Sunday, but will probably be slowed as it moves into the coastal area. Only scattered showers are likely, with some periods of partial clearing. Pressure gradients appear likely to be weak, meaning fairly light winds.
Monday, a stronger impulse will brush through. That's likely to result in more widespread showers, more clouds and more cooling.
On the Trail
Showers may linger over the mountains Friday; any that do form will be scattered and sparse. The snow level is likely to range between 6,000 to 6,500' with pass temperatures in the low to mid 50's. Pass winds will likely be easterlies at 5-15 mph. Ridgetop winds will be northeasterly as well, 15 to 20 mph. Take sturdy tent pegs! Saturday should be mostly sunny with a freezing level near 7,500 to 8,000'. Pass highs should warm into the mid 50's to low 60's, with pass winds from the north-northwest at 10-15 mph, and very similar on ridgetops.
Clouds will increase Sunday becoming partly to mostly cloudy, with at least a few scattered showers. The snow level should range from 5,500 to 6,000' with pass winds from the northwest at 5-10 mph, then westerly on ridgetops at 10-15 mph. Monday I expect will be mostly cloudy to cloudy with mixed snow and rain showers with the snow level likely to drop to between 4,500 to 5,000'. Pass highs will probably range in the mid 40's to perhaps the low 50's at most. Pass level winds will be westerly but probably light; about 5 to 10 mph, but on ridgetops, expect southwest winds 20-25 mph.
Take your raingear, a good insulating layer (but also sunscreen) and a means of staking your tent down. If you must remain into Monday, consider an early departure...or take a good book of packable game for entertainment during showers!
On the Water
Friday and Saturday will be nice days to be on the water. Mostly sunny skies, though brisk northerly to north-northwesterly winds will make for great sailing but rough cruising/kayaking on Friday. Along the coast and the interior, expect winds of 10-25 knots, especially Friday afternoon. Only the east end of the Strait is likely to see winds that strong; the central to west Strait will probably run 10-15 knots at most. Expect temperatures to range from near 60 along the coast to the mid to upper 60's inland.
Saturday marks the beginning of the Swiftsure race through the Strait. Winds can either be blustery or maddeningly light. Saturday is likely to lean a bit toward the maddeningly light, especially in the morning with light westerlies through the west and central Strait, though perhaps reaching 10-15 knots in the eastern Strait in the afternoon. Still, most racers should be farther west at that point. North of Port Gardner on interior waters, northwest winds of 10-15 knots are likely, and on the Sound, northerlies of 10-15 knots. Skies should still be mostly sunny, and temperatures a bit warmer than Friday.
With the approach of the disturbance Saturday evening and early Sunday, winds will rise, probably reaching 15-30 knots. That's likely to happen first near the west entrance of the Strait, then move east through the Strait after midnight Saturday. Sunday, expect winds to back to the east or southeast and diminish in the Strait, probably to 10 to 15 knots. The northwest interior (including the San Juans) should see south winds of 10-20 knots, while Puget Sound should see 10-15 knots from the south. Expect partly to mostly cloudy skies with a few scattered showers; highs will cool into the mid 50's to low 60's (for highs.
Monday, expect south to southwest winds over the interior waters at about 10-15 knots, westerlies through the Strait at 10-15 knots and light southwest winds along the coast at perhaps 10 knots. Needless to say, subtle changes in the movement of the key pieces on the weather map can lead to changes in the wind outlook. Get updated forecasts frequently. Remember, showers are more likely Monday with cooling temperatures, probably dropping into the mid 50's to near 60.
Enjoy your weekend, be safe, re-apply sunscreen frequently!
Jeff Renner, KING 5 Chief Meteorologist and "Field Researcher"
