Snow Keeps Piling Up…

January 31, 2008

SnapshotI’ve just been amazed at the numbers this evening.  The snow depths and snow water increases just today.  Looks like Mt. Hood Meadows has had 3 feet of snow in less than 2 days…16" of that just since 5am today!   That graphic down below, from last night’s post?  I notice Saddle Mountain now has over 28" of snow water.  That’s about 3" of precipitation since last night at this time…all falling in the form of snow.  By the way, ever wonder how they measure precipitation at these remote sites with no electricity to warm the gauge?  It’s an open container/gauge that uses an anti-freeze type solution.  The snow falls into it and melts, gradually filling up the thing as the winter goes on.  That depth is then measured (or it might be by weight, I’m not sure).  Either way they go up there and swap out the fluid each summer.

Our weather?  Rainy and breezy this evening…with the trough moving through.  Snow levels have fallen a bit below 2,000′ again and probably bottom out around 1,500′ tomorrow under much lighter showers. 

Our model indicates steady stratiform precipitation arrives from the next system by midnight tomorrow night.  00z models are a bit more similar on the Saturday low pressure placement.  They seem to agree on a strange "double-low" setup that brings a negative-tilt front up towards us from the southwest early Saturday morning.  WInd turns a bit more southerly behind that feature as we then get a secondary low that moves almost directly over us late Saturday.  Since we don’t have really cold air already in place, I think it’s going to be tough to get sticking snow down to the Valley floor.  This MIGHT be a good time for a quick snowfall up against the Coast Range.  It’s a brief easterly flow ahead of that first wave, and southeasterly flow around 2,000-5,000′.  That pattern in the past has produced "unexpected" snowfall at Forest Grove, Banks, and Gaston.  We’ll see.  In general I’m just not too excited about any "event" Saturday.  Just not quite cold enough.  There IS one more day to take a look at things, so no need to make any prophetic announcements on the air.
It IS going to be a great snowstorm in the foothills and Cascades though…just what we need, more snow…Mark Nelsen

When Will It End?

January 30, 2008

SnapshotThe numbers might be a bit hard to read, so you can click on the image for a larger view.  The big picture shows that we now have the largest snowpack on record since sensors were installed in the Coast Range in 1979!  Discuss among yourself while I do my job here in the next 20 minutes…more after the weathercast…

Okay, back now…isn’t that snowpack incredible?  What’s interesting about the big snow year is that it’s only at the lower elevations.  Higher sites such as the Timberline only have slightly above average snowfall.  Also, I notice that at Saddle Mountain the precipitation for the season is actually slightly below normal.  That clearly shows that our storms have been unusually cold this winter.  What snow has fallen has fallen to a lower than normal elevation and we haven’t had any warm/rainy events since the first 2 days of December.

As for flood concerns, as I mentioned at 10pm, it’s not necessarily a problem to have a huge snowpack.  The problem is only if we get a sudden warm and rainy period.  I sure don’t see that in the next 7 days.  But it’s something to keep a close eye on.

Tonight’s storm has pushed the snow level up to around 2,000′.  It’ll stay there through tomorrow night, then drop down to around 1,000′ again by late Friday afternoon.  The whole time, strong westerly flow at 850mb. means a continuous dumping at the mountains.  Basically the snowstorm that began Sunday more or less continues through Friday afternoon!

Saturday:  This is interesting…a surface low comes across the Pacific pretty much straight into the Northwest.  Models runs have been all over the place on landfall location.  The 00z GFS is just slightly north of Astoria (maybe a bit of "dumbelling"?).  The 00z NAM moves the low farther south, into the Central Oregon Coast.  Still a couple days to decide.  The thought is that if the low moves inland to the Central Oregon Coast, our wind in the metro area would turn northeasterly with plenty of moisture and 850mb temps well below 0.  That is a good setup for snow with heavy precipitation falling.  If the low goes any further north (lets say north of Astoria), we just get south or southeast wind and a 1,000′ or higher snow level.  There appears to be good lifting and plenty of moisture with that system, so we’ll get quite a bit of snow in the hills and Gorge either way.  Wow, another 2′ of snow in the Cascades AFTER the 2′ we have coming tomorrow and Friday!  Some models indicate a change to more normal temps & weaker systems after the middle of next week…we’ll see…Mark Nelsen

More Snow

January 29, 2008

SnapshotAnother very fun weather day, but frustrating for forecasters (as snow situations always are).  Considering that I put the forecast for low elevation snow at NONE last night, it was a bust for those of you down the Valley.  Models clearly showed the comma-type feature of heavy showers that gave us the snow.  But it looked like it would travel mainly into the S. Valley.  That’s why I pretty much ignored it.  The only reason we didn’t get an inch or two of snow here in Portland is that we were at the far northern edge of it.

Moving on…models show the last little batch of showers coming in from the northwest around daybreak tomorrow.  I see no reason why healthy showers wouldn’t push the snow level back down to the surface again.  That’s how I get the Trace-1" additional snowfall.  I also notice the southerly gradient up the Valley has weakened a bit too and should stay that way overnight.

The next system is approaching very quickly from the west.  850mb temps are a bit higher with this system since it’s coming in more from the west than the northwest.  Same thing for Thursday as well.  Then a colder atmosphere comes back over us Friday through Sunday.  Lots of possibilites over the weekend depending on which model you look at.  More fun coming up…Mark Nelsen

Snow Totals Tuesday Night

January 29, 2008

Here we are again…cold onshore flow and snow to the lowest elevations:

Put your snow totals in the comments.

NEW SNOW (only amounts over 1/2" please)
ELEVATION (if you know it)

Please keep discussing weather in the other posts

Snow Tonight?

January 28, 2008

Photo2 Snapshot
Feeling left out by the weekend snowfall?  They probably don’t feel the same way out in the middle of the Gorge!  Mike Engel took this picture today, showing the 27" of snowfall that pretty much buried his car…very impressive don’t you think?  You can click on the picture to see a larger version.

(Previous discussion follows)
I just had to say something…I seriously doubt we’ll see sticking snow in the lowlands tonight (at least in the metro area). 

I see the NWS has a snow advisory for 2-4"?  Hmm..way too much south wind, no easterly flow through the Gorge and generally just a bit too warm…just barely.  But tonight is the time to be in the Coast Range, Gorge, or above 1,000′, that’s for sure.  More details later when I have time…

(Current discussion continues below)

Sorry, I just had to do that…it seemed so official…I should correct that statement about the 2-4" though.  The NWS has it in their statements pretty clearly that there won’t be 2-4" at the lowest elevations tonight.

Solid rain/snow from the approaching cold front now filling in the radar screen nicely.  Based on the KPTV Tower temp (30.5 at the top), I’d estimate the sticking snow level to be around 1,000′ right now.  That’s once precipitation actually begins falling nicely.  I think it’ll briefly dip slightly lower than that, but not much.  Too much mixing with a southerly wind up the Valley.  It’s very interesting that the "warming" we get ahead of this cold front doesn’t even push the freezing level above 2,000′ or so overnight.  So those of you in the 1,000-2,000′ elevation spots (and the central Gorge), have a nice little snowstorm for tonight.

We get post-frontal showers tomorrow, our model here says a few thunderstorms possible too.  This time of year that’s most likely only at the Coast.  Then 2 more systems come through, just a bit warmer by the way, on Wednesday evening and again Saturday.  Still, no snow levels much above 2,000′ through the end of the week.  This is going to end up being a heck of a snow year for the Cascades!

By the way, for Unscripted tonight at 10:52pm, we’ll ask viewers if they have questions.  It should be entertaining don’t you think?  I don’t plan to look like an idiot, but if so, we just won’t do it again.  It never hurts to try something once.

I think we’ll leave it there.  I was surprised at the variance in snow totals this morning.  I see Council Crest had 2", Steve Pierce in Vancouver had half-dollar sized snowflakes at 2am, and inner east Portland got nothing.  Frustrating indeed…

Mark Nelsen

Frustrating Forecasts

January 27, 2008

SnapshotWhat an interesting day it has been.  For the first 14 hours of the day, a stationary front and it’s associated steady, heavy precipitation was draped across Northwest Oregon.  The back (western) edge of this snow-producing band was along a line from Troutdale to Salem to Corvallis.  All areas east and south of that line had significant accumulations of snowfall.  In fact it WAS the big snowstorm of the winter for those spots.  It was probably the heaviest snow in years for Lebanon, Sweet Home, & Albany.  Maybe Sandy too.  At my home in Corbett it was the heaviest snow since the 2004 Ice/snow storm.  BUT, east of that line we’ve seen little to no precipitation now for 12 hours!  Does everyone realize that if the back edge would have been 25 miles back to the west, we would have had FIRST LIVE LOCAL weather coverage all day???  The 5" of snow that "no one predicted" would have been the refrain.  Once again location is everything.

Radar shows showers still moving onshore, but they are weak and not really making it over the Coast Range.  That’s too bad since we now have the coolest atmosphere overhead and it’s cold enough to snow anywhere inland.  That’s why I’ve taken out references to elevation in my forecast graphics.  Which reminds me…didn’t I go on a rant in Friday’s blog about forecasting the snow level (200, 300, 500′)?  Today illustrates the point perfectly.  No snow at 1,000′ in the West Hills, yet 5.5" at 300′ in Mulino.  Always remember that snow level is not only dependent on temperature, but precipitation intensity as well.

Moving on…I see no reason that we’ll get anything other than light flurries overnight, EXCEPT for one thing.  The insistence by models that the weak surface low moving down the Washington coastline will be over PDX about daybreak as it weakens.  There should be some lift with this feature, plus no wind of any sort to screw things up.  That tells me that even a few brief showers will turn things white.  That’s how I get my forecast of a Trace-2".  If we don’t get at least white ground by morning, then I’ll admit defeat for this weekends big "BEST CHANCE FOR SNOW IN THE CITY YET" promotion on my Friday weathercast.  I was pretty wound up about the chances.

After tomorrow morning, I don’t see a situation quite as good temp-wise through the next 5 days or so.  The amount of snow at/above 1,500′ is going to be incredible a week from now!  But it’s going to be tough to get the snow level much below 1,000′.  Lots of south wind and no arctic air involved.  Of course tomorrow evening’s system will move moving into our already-chilled airmass, so it’ll be close again.  Most likely a lot of snow in the air, but only sticking up around 1,000′.

On another note, I notice a lot of bitterness, angry words, and general crankiness on the blog today.  It’s obvious that we’re all tired of the "near-misses".  But remember that we all read (or write) on this blog because we have the same interest in weather.  I suggest taking a break for a day or two.  Hard to believe, but you CAN get burned out on weather.  It happens to me after several long days of active weather.  Pray for a Trace to 2"!

One more thing, to many of you this blog has become a place to "hang out" weatherwise.  I appreciate the help that you provide to me as well.  There have been many times this winter where I read the comments quickly during a newscast to see who’s getting what.  Thanks again. …Mark Nelsen

Snow Totals Sunday & Monday

January 27, 2008

As of 8pm Sunday (Condensed from comments):

18.0" Cascade Locks (200′)

6.5" Corbett (1050′)

8.0" Sandy (850′)

5.0" Cherryville (900′)

4.5" Estacada (500′)

9.0" Estacada (1,000′?)

10.5" Beavercreek (1,100′)

10" Colton (1,000′)

5.5" Mulino (300′)

3.0" Molalla (500′?)

4.0" S. Salem (500′)

3.5" Stayton (500′?)

4.0" Albany (300′)

1.0" Corvallis (300′)


6.0" Sweet Home (580′)

6.0" Eugene (400′)

Keep adding to the comments if you have other totals or yours increases by more than 1"

Snow depth, location, and elevation if you know it.