Mountain Snow Forecast: March 14-16th
Updated Friday, Mar 14 at 7:06 PM
We've had a couple of days of 'snow drought', but that's coming to an end. Given the pattern we expect this weekend (and for that matter, today, Friday, as I write this) selectivity will be necessary to put you into fresh stuff. I'm looking forward to reacquaint myself with our local turn-around story in the snowpack, after enjoying some time in the Colorado Rockies. They're having a good snow year, but needed it. Hopefully their repeated large snows will aid in recovery from a persistent drought and elevated fire danger. Our late but much improved snow season should help limit the same problems here.
THE SNOW MAP: The passage of a front this morning has led to a moderately strong onshore flow; strong enough to produce a Puget Sound Convergence Zone that has generated thundershowers with small hail over north King and south Snohomish counties. Those thundershowers have ended (at least now), but moderate to heavy snow is falling in the Stevens Pass area...and the snow level has dropped to 4,000'. Still getting rain at Snoqualmie, though the upper parts of Alpental are seeing snow. Satellite imagery shows a cloud shield racing out ahead of a warm front; that will bring areas of precipitation Saturday after a breather tonight. The main trajectory of the system will be north of Snoqualmie, though some precipitation will be possible in the morning.
Saturday night and Sunday that front will sag slowly southward for increased precipitation. Snow levels will begin fairly high (see below SNOW GAUGE section for specific estimates), which will make for a wet period. Much cooler air will follow that front Sunday night and Monday, leading to much lower snow levels. The likely onshore flow will lead to another punch of fairly heavy snow, again tending to favor the central Cascades-i.e., Snoqualmie and especially Stevens Pass. Skiing/snowboarding in July, anyone?
THE SNOW GAUGE: The snow level could begin as low as 4,000 to 4,500' Saturday morning, but then rise as high as 5,500 to 6,000' Saturday afternoon. Doesn't sound good-except that the likelihood of precipitation will rapidly drop off Saturday late morning to early afternoon in most areas except the North Cascades. And the amounts in those areas from Stevens pass south will be light; at or above the snow level, expect trace to an inch or two at most. Mount Baker will probably pick up 1 to 6".
Sunday, snow levels will likely begin the day around 5,000 to 5,500', but then drop to between 3,000 to 3,500' in the afternoon. Snowfall at Snoqualmie, White and Crystal will probably be minimal-an inch perhaps. But Stevens could pick up 2 to 4", and Mount Baker up to a foot. And if Monday is an option for you, plan a trip then-we could easily pick up a foot or more at ALL areas.
THE COMFORT METER:
Saturday-Periods of light rain or rain and snow from Stevens pass south, mainly in the morning, then again late afternoon to evening. A mix of rain and snow, moderate at times, north of Stevens pass. Southeast winds 5-10 mph near the base, but southwesterly 30 to 45 mph on exposed ridges and summits-but not until the afternoon to evening hours. Expect pass highs in the low to mid 40's, and ridgetop temperatures in the upper 30's to low 40's.
Sunday-Expect west winds at 5 to 15 mph by the mid to late afternoon near the base, but still ripping from the southwest at 35 to 50 mph on higher exposed ridges and summits.Base temperatures will be in the mid to upper 30's, with summit max temperatures running in the low to mid 30's, with the cooler temperatures obviously on the highest peaks and ridges, later in the day as cooler air pushes inland. And yes, it will be wet. Very wet.
BEYOND THE LIFTS: Avalanche hazards are rated as considerable in most areas of the Olympics and Washington Cascades, moderate only in some areas below treeline. The biggest concerns are wind slabs on southeast to north facing slopes and storm slabs on all aspect near and above treelines.
My recommendation as I've emphasized before, and will repeat now...do what I do whenever I head into the backcountry; check the Northwest Avalanche Center at www.nwac.us. Don't ski or board alone, and watch each other carefully as you head downslope! As the NWAC experts emphasize, make every trip a round trip!
To borrow a quote from Indiana Jones and the Last Crusade-You must choose, but choose wisely!
Jeff Renner / KING 5 Chief Meteorologist (and chief skier!)