Sunday, November 25, 2012

Arctic Air, Nowhere Near

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I can't even begin to tell you how upsetting it is to write this blog post.  As you know, I love cold air and snow, especially around Christmas time.  I have been searching far and wide for any signs and now I can't find any.  Last week, there was a glimmer of hope, but it has faded away.  While Monday and Tuesday will both be cool, we're going into a fairly zonal pattern which means the jet stream is oriented from west to east.  This will lock the cold air in Canada for at least the next week and probably beyond.   Much of the country will be flooded with mild, Pacific air.  We need the jet stream to buckle (amplify).  There's a ton of cold air over Alaska and Canada.  For that air to get "unlocked", we need ridging along the west coast into Alaska and western Canada.  The circulation around that would cause a downstream trough and deliver winter's chill.  However, I just don't see that happening through the beginning of December.  

We also have to remember, it's early. It's not even winter yet!  At some point the cold air will come south.  I just hope it's in time for Christmas.  Stay tuned.

Below are maps which explains the situation.

Looks confusing?  I'll explain.  This is the latest version of the GFS valid next Saturday morning way up in the upper levels of the atmosphere.  The jet stream (orange and yellows) is oriented from west to east across the United States.  This is the zonal flow I was talking about.   Notice the troughing west of Canada.  This is where a ridge needs to build to dislodge the cold air.  I just don't see that happening anytime soon.
This is the GFS surface temperature valid next Saturday morning.  Notice the cold air is locked up in Canada and Alaska.  The model sees air as cold as -25 degrees F. up there.  The solid white line is the freezing line at the surface.  It's nowhere near Arkansas.  Much of the country is flooded with mild, Pacific air.
This is just an example of what would bring that cold air south.  Look at the ridging along the west coast into Canada.  That along with the large area of low pressure over central Canada would allow arctic air to move south.  Maybe we can get the upper level charts to look like this down the road, but I just don't see it anytime soon.

3 comments:

Snowbirdbob said...

I have to agree with the Post, Last week the Models looked as if we were headed for a Cold & Stormy Period..as Todd stated,that has pretty much vanished.I sent out a Tweet today talking about the NAO & AO being strongly negative & most models are showing it staying negative for the near future..Those factors are strong indications of what our weather maybe 10-20 Days down the road...We need the Greenland Block to make its presence felt..We also need the ridge to pump over Alaska, If we cant get those two aligned..Then Watch Out..Yes, The Negative AO & NAO is telling us something...What may be a good thing we get out of all of this, The longer the Cold Builds up there, The higher the pressures builds & The Cold expands with time.It also gets Colder..Did you know that when we talk about Arctic Air masses coming south..Its not considered True Arctic Air unless its comes from Siberia or The Arctic Circle..Many times during the Winter we get Arctis Intrusions & We call it a Arctic Attack...True..Its Cold, But the correct term that we mostly see here in the south is Continental Polar Air, These Airmasses Can be extremly cold also, dont get me wrong..These airmasses originate in Alaska & Northern Canada...Getting back to how cold air gets here..Not only is the NAO & AO partial, We have to add the El Nino, La Nina or La Nada...Right now it looks as we head deeper into the Winter we will be in a weak El Nino to La Nada..Well, I put those together to see what we might can expect..If we can get the NAO & AO to stay Negative..It should lead to a Below average Temps here from the Plains east Including us here in the Deep South..Precip.. Well, it could be Normal to Below...I do think as we head into Mid-late Dec. It will turn colder..But, we may have to wait until Jan. Feb for any Huge Jailbreak Arctic Airmasses..If we get any at all..Long-Range forecasting is impossible out to about 5 Days..I know I go out there some, But, I just dont guess or throw something ouththere..I do overall think this Winter will be Much Colder & More Wintry than last year...Just have to put our be Calm Cap On..LOL..We Shall See...By the way if you want to like my facebook page Snowbirdbob..I do videos weekly & alot of wishcasting & forecasting on there..Its a fun place..Thanks for Reading :)

Bob Read AKA SnowbirdBob

Will said...

Don't be upset Todd as there is no crying in Meteorology...

I think you are about three weeks too early. Like most other I am a weather fanactic and a big fan of SNBob. I've been reading some of the entries on the American Weather forum and some of the more respected posters are hinting at some possible upcoming pattern changes. Who know, this might be SnowbirdBob's year.

Anonymous said...

These are dark times.