Snow or No Snow?

November 19, 2010

It’s STILL a tough forecast for snow here in the lowlands, but at least the other half of the forecast is pretty much nailed down…Cold!

We have new anchors for the duration of our First Live Local Great Freeze of 2010 coverage…

 Actually the penguins are a funny story.  They are named George and Gracie.  They’ve been floating around the studio and/or weather center area for over 10 years!  Those little plastic pieces of  junk were at the groundbreaking ceremony for this building back in 1999.  The theme for the food was a Luau and somehow the penguins were on the buffet table.  Of course I have no idea how those go together, but they’ve lasted through a brand new Fox-49 studio and newscast, a merger of Fox-49 and UPN-12, then change to Fox-12 soon after, a move from the smaller studio to our larger one with the new weather center 4 years ago, and about 10 different weather people.  I’m still here and so are the penguins.  Actually the General Manager of the station mentioned something about “throw out those stupid penguins!” 3-4 years ago, but somehow they are still here.

Moving on…nothing very exciting for this weekend.  Most shower action heads south of here Saturday and Sunday as a new upper-level disturbance (and surface low) drops down the Coast tomorrow and then heads east through eastern Oregon on Sunday.  This sets up an easterly surface wind tomorrow and early Sunday, then the onshore flow returns Sunday afternoon through early Monday as a new surface trough (actually more like an arctic front) forms east-west across Washington.

At least all models agree on very cold air moving south out of Western Canada Monday-Wednesday.  Note that after tomorrow’s easterly wind, we don’t actually get a gusty east wind through the Gorge because the cold air is coming straight from the north.  Pressure gradients are real flat Monday through Wednesday.

So now that we know the cold air is coming, what about the moisture?  Seems to be in two camps this evening.

One is the NAM and UW’s NAM-MM5, which spins in of plenty of cold showers Sunday evening all the way through Monday evening.  This would be a great setup for snow in the lowest elevations, especially later Monday as freezing temps at the surface work south.  But since the NAM has a stronger surface development to the north Sunday night through Monday morning, it would be tough to get snow to the valley floor at that time (due to the stronger southwest wind).  The NAM could give us the “real-deal” for at least an ince or two of snow, but…

In the other camp is the GFS, WRF-GFS, and our own RPM.  They minimize any development to the north, keeping showers going south of Portland through Monday.  In this case the best chance for snow is down the Valley and in southwest Oregon (Roseburg).  These three models effectively keep us dry from later Sunday evening onward; a partly cloudy or cloudy day Monday but no snow OR rain.

So which one is correct?  Could be either.  We’re still 48-60 hours away, so hopefully models can get it together.  At least that have the basic idea correct (cold, with a chance of sticking snow).

Chief Meteorologist Mark Nelsen


AMS Meeting Tomorrow!

November 19, 2010

Don’t forget, tomorrow is the big day, and I’ll be there with a few little FOX12 goodies to give away.  Actually, don’t get too excited, no TV’s or umbrellas…I’m sure we’ll have PLENTY to talk about weatherwise.  Brrr!!!!  Mark

  4th Annual KPTV Weather Blog Pizza Feed & Joint AMS Meeting Reminder!

The November Oregon AMS meeting will be held Saturday (tomorrow) at Stark Street Pizza, 9234 SE Stark St in Portland from 1pm to 4pm Saturday. This meeting is once again being held in conjunction with the 4th Annual KPTV Weather Blog Pizza Feed. Come meet members of the KPTV Fox-12 Weather Team, have a cold beverage and eat some of the best (no-host) pizza in town! For a map to this location and additional AMS details, please click: http://www.ametsoc.org/chapters/oregon/
This event is open to all ages of the public. A social hour will be held from 1pm-2pm with the meeting commencing at 2pm. There will also be the usual “weather update” as well.

Hope to see you all there, rain, shine (or snow?)

Steve Pierce
Vice President
Oregon Chapter of the American Meteorological Society (AMS)
503-504-2075 (Portland)
e-mail: stevejpierce@comcast.net
web site: http://www.ametsoc.o…hapters/oregon/