Forecast - The Gorge is my Gym

The Clymb: free membership.
Access to super cheap gear including Trew, Zeal, Sierra Designs, and many more.

—

Good morning!
In yesterday’s forecast, there was a typo. I meant to say the “Arctic Oscillation,” but put Pacific Decadal Oscillation instead. That’s 5am brain for you. Anyway, they both affect the weather in the PNW, but on different time scales. We are currently in the cold phase of both, which is contributing to the storm path being in the incorrect place for pow-pow on Mt. Hood.
But first, today’s weather on Mt. Hood. Temps are above-freezing again this morning, and it’s looking like the snow level won’t fall below 5000’ until after 4pm. However, once the temps start dropping, they’ll drop fast, and the snow level will be at 2000’ by 10pm, falling to 1000’ by Saturday morning. The precipitation will start around 1-2pm, which means we’re probably going to see some r**n today. Heaviest precip will happen between 4pm and midnight, for some r**n, followed by some snow. I think we’ll still see 4-6” of new by tomorrow morning, for a total water value of .5”-.75”. Winds today start at WSW 15-25, building to W 25-35 by 4pm.
Tomorrow starts with light snow flurries and the snow level at 1000’. Heavier snowfall will happen between 1pm and 10pm. Total accumulation 4am to 10pm will be 3-5” with water value of .25″-.5″. Winds tomorrow will be WNW at 15-25 all day.
Sunday brings intermittent orographic snow flurries and sunbreaks all day. Total water value will be less than .25″. Snow levels start at 1000’ and drop to the surface. Winds will be WNW 5-10 in the morning, becoming light in the afternoon.
Monday and Tuesday look cold, clear and calm with the free air freezing level at the surface and light east or north winds on the mountain.
If the forecast holds for Wednesday, the Gorge is ******. Very cold air at the surface clashes with an overrunning warm system containing 1-2”+ of moisture. At this point, it looks like the snow level with this system will be at 5000’, except in the Gorge, where it will be at the surface. Cold air will remain in place through late Thursday or early Friday, meaning well over a foot of snow could fall in the Gorge. This is great if you want to skin or bootpack Hospital Hill, but not so great if you want to drive somewhere. If this forecast holds, expect I-84 to close. On the other hand, the moisture could miss us entirely. Stay tuned.
Have an awesome day today!
Temira

p.s. If you find this report useful, entertaining, or just want to recognize all the hard work that goes into it, please take the time to make a donation by clicking on the button at the bottom of the page. For a suggested donation of $10, I’ll add you to the email version of this list ‘til November 2011, putting you in the running for cool prizes donated by the weekly sponsors.

The Clymb: free membership.
Access to super cheap gear including Trew, Zeal, Sierra Designs, and many more.

—

Good morning!

Although we all hope for lots of moisture during a La Nina season, today is one of those days when we’ll leave the moisture for a different mountain range. Free air freezing levels today will be around 8000 feet, but fortunately, precipitation will be light and spotty all day. However, any moisture that falls will fall as r**n. Winds will be SW at 15-25mph this morning, decreasing to WSW 10-15 this evening.

Tomorrow looks better. Free air freezing levels start the day around 7000’-7500’. By the time the moisture hits, around 1pm, the snow level should be down around 5000’. If not, it will be down to 5000’ by 7pm, when the bulk of the precipitation hits. By 1am, snow levels will be down near 1500’. Total precipitation between 1pm and 10pm will be .5-.75” water value, for 6-8” of new snow. We’ll see an additional 3-4” overnight. Winds tomorrow start off at WSW 15-25, increasing to WSW 25-35 by 4pm.

Saturday looks cold, with snow levels at 1000’-1500’. Total water value on Saturday will be .25”-.5” of orographic precipitation, likely mixed in with sunbreaks. Most of that moisture will fall before 4pm, for 4-5” of snow. Winds on Saturday start at NW 15-25, decreasing to NW 10-20 late in the day.

Sunday looks cold and mostly dry, with light wind and sunshine. Snow levels Sunday will be around 1000’.

In case you’re wondering why California has been getting the bulk of the moisture so far this year, I have an explanation, stolen from an article by a Cali meteorologist. There is a second, climate cycle that affects the PNW, called the Arctic Oscillation (well, there’s a third too, the PDO). According to the author of this article, it’s random, switching between the cold and warm phase on a weekly or monthly or who-knows basis. Anyway, it’s in the cold phase now, meaning there’s high pressure in the arctic. That high pressure is pushing the storm track further south than it would normally be, sending the big storms to Cali. Or that’s the theory, anyway… food for thought.

Have an awesome day today!

Temira