Where’s the Snow?

Hopefully this is a fair assessment of my forecast from last night.  It’s the same graphic on the previous post with my notes on top.  My boss said "where’s the snow?" as soon as I showed up at work today.  It sure was a nice snowstorm up closer to 1,000′, but too bad things didn’t at least turn white down below.  But it’s time to move on, considering that only 2-3 degrees separated us from a little Portland snowstorm today!

Not much to talk about tonight and tomorrow…a weaker system moves into Southern Oregon tomorrow.  Then a much stronger area of low pressure tracks to our north late Saturday and early Sunday.  We should get quite a gusty south wind Saturday night and all day Sunday.  That’s why even though a 1,000′ or lower snow level is quite possible, I’m not too wound up about it.  A showery airmass with strong onshore flow means it’s going to be tough to get the snow level real low.

Lots of high pressure builds in to our east Monday-Wednesday…A big east wind event is coming.  Rob get the gradient watch dusted off!

As for the Polar Bear picture.  Next Tuesday, New Year’s Day, at 11am, several weather people in town will be taking the "polar bear plunge" into their pool up at the Oregon Zoo.  I would ASSUME that they clean out the hair and poop first, but maybe that’s asking too much.  Anyway, it’s a fundraiser for the zoo and it sounded like a fun/wacky thing to do.  Of course when you look at me don’t you think "fun & wacky"? 

I think Dave Salesky and Bruce Sussman (assuming he isn’t on his deathbed), will be joining me as well.  The pitch?  If you want to pony up a $500 donation, you can join me too, but only an additional 7 people are allowed in the pool.  So who’s first in line?  Any takers?  Go to the Polar Bear Plunge website for more details and to sign up.  Shauna suggested I have a big chunk of ice to toss around the pool like the bears do.  Of course she didn’t offer to join did she???  Mark Nelsen

Snow Totals Thursday

If you have at least 1", please put your snow totals only in these comments.  We need several things:

LOCATION, ELEVATION (if you know it), SNOW TOTAL

CONTINUE DISCUSSING WEATHER ON THE OTHER POSTS

New Snow Totals (does not include leftover snow on ground, just today’s storm):

10-12"  Hills above Woodland (800-1000′)
6"    Hill above La Center (700′)
4"    Chehalem Mtn. (1,500′)
4"    North of Camas (1,000′)
3"    Mt. Scott (1,000′)
2.5"  Council Crest Park (900′)
2"    Prune Hill-Camas (750′)
2"    Corbett (1,050′)
2"    West Hills, Germantown/Skyline (950′)
2"    Ridgefield (300′)
1"    Happy Valley (600′)
1"    Cherryville/Marmot area (900′)   

Tough Snow Forecast

So here’s what I’m thinking for the big "storm" tomorrow.  The basic idea is that we are all going to see some white, like we did on Christmas Day, through the morning hours.  Assuming the precipitation falls at a significant clip, which it should, all of us should see some white on the ground as well.  That said, increasing southerly flow in the 1,000-2,000′ elevation (20-30 mph) is sure going to be fighting against the precipitation rate.  So this should be a snow event where elevation makes a tremendous difference in snow totals.  Notice I’m forecasting possibly 2-4" at the top of the West Hills, but maybe almost nothing down IN Portland "proper".  Put another way, if you want to go sledding tomorrow or build a snowman, I think you will probably need to be at least 500′ or above.
or another…I doubt we’ll have any travel issues on the main city roads/highways.  Only in the higher hills will you find slush and then totally snow covered roads as you get well above 500′.

The reason I don’t think we’ll have the 3-7" the NWS is forecasting are these:

1.  Airmass is pretty much the same (except for overnight cooling tonight) overhead that we had Christmas Day.  That was also a very marginal event, but produced a widespread dusting with only about 1 hour of steady moderate precip. 
2.  Precipitation appears to be quite light until early afternoon, not the real heavy stuff that could drag the 32 degree line down to the valley floor.  Yes, the precip. gets quite a bit heavier as the cold front approaches mid-late afternoon, but much stronger southerly wind gets going above the surface at the same time (notice 00z MM5-Cross-Section).
3.  Our RPM model here says the same thing…slightly too warm, especially after 10am. 

If we don’t get sustained and moderate precip in the morning, then we could end up with nothing in the city…hopefully that won’t be the case.

I think we all agree on this…it’s going to be a dramatic warmup with a gusty southerly wind after 4pm.  The snow level jumps up to 2,000′ and then stays above there until early Sunday.

Mark Nelsen