HEY OHHH FOR THE AO
Written by: Bob Metcalfe
So for those who are dreaming of more cold, you may not like this information. At least from this one piece of data. The arctic oscillation (AO) is looking more and more warm in the next few weeks. That's the image I've posted.
The AO is a measure of the height anomalies over the arctic. You should read this as lower numbers mean colder, whereas higher means warmer. Notice how low the readings were through the month of December with the forecast taking a sharp turn to the upside. This indicates warming in the arctic which is obviously the major source for any east coast cold.
This is just one cog in the many that make up our winter forecasts that extend beyond a week or so. The NAO is still showing negative, but without that cold source, you won't feel the chill quite as much.
Bob,
ReplyDeleteI guess i'm a little confused by your analysis. While it is true that the AO will become "less negative", it is projected to remain negative by the vast majority of the members. Furthermore, after becoming less negative, it is shown to begin to plunge deeper into negative toward the end of the time frame. Our cold source will still be there. And for further proof that we will remain cold is supported by the NCEP ensembles for the 850 mb temperature anomalies. They have very cold temperatures by in around two weeks, which is supported by my aforementioined plunge in the AO by the indices you are pointing out. I'm afraid I have to disagree with your analysis - particularly when you state it is looking more and more warm for the next "few weeks." Check back around January 10th and see if that is the reailty.
Why does Bob always seem to throw a knife into the hearts of snow lovers. He is always stating that snow lovers will not like this. I know he has to give us what he sees but he always makes it a point to point out warmth and no snow. I do not think he likes snow.
ReplyDeleteI agree! It seems Bob enjoys sticking it to us snow lovers when he writes his pieces. Not sure but Bob himself said bigger storms come when the temps are not real cold. Beware of Jan. 5th on for about 10 days something coming hopefully here.
ReplyDeleteIn Bob's defense, he didn't say anything about whether this would mean more or less snow.
ReplyDeleteI agree SnowFan! I am happy to read that that there is a glimmer of hope for something around the 5th..Will it be snow? Cold? Lake Effect? or Synoptic snow? That would be wonderful. Especially if it gets down here to Sparta in Livingston county. I just put a 3 inch lift on the Silverado and a fresh set of rubber on it so I am ready to push some snow!!...and go dashng thru the 22 acers of fields I have out back too!! I will keep the fingers crossed and keeping the blog daily for updates!!!
ReplyDeleteI personally am not a snow fan, but I do love a good storm. So, with that being said I love it when we get pounded by snow, it can be LE or Synoptic doesnt really matter to me. Then again I live in Wayne County.
ReplyDeletePutting the snowblower away. Does not look like we will need it for quite sometime. Let the melting begin.
ReplyDeleteJanuary looks to be cold and possibly snowy.
ReplyDeleteFrom Don Sutherland.
f one examines data consistent with the forecast teleconnection indices centered around 1/10/2011 for past January La Niña cases with an ENSO Region 3.4 anomaly of -1 or below and also examines the 12/29/2010 0z GFS ensemble means forecast for 312 hours, one finds:
GFS ensemble 500 mb height anomalies: 312 hours
http://img.photobucket.com/albums/v327/donsutherland1/GFSens122920100z312h.gif
GFS ensemble 850 mb temperature anomalies: 312 hours
http://img.photobucket.com/albums/v327/donsutherland1/GFSens122920100z312htemps.gif
Composite 500 mb Height Anomalies: January Cases:
http://img.photobucket.com/albums/v327/donsutherland1/AO5.gif
Composite Temperature Anomalies: January Cases:
http://img.photobucket.com/albums/v327/donsutherland1/AO5temps.gif
If one then rolls the January cases forward 10 days, one finds:
Composite 500 mb Height Anomalies: January Cases:
http://img.photobucket.com/albums/v327/donsutherland1/AO510d.gif
Composite Temperature Anomalies: January Cases:
http://img.photobucket.com/albums/v327/donsutherland1/AO510dtemps.gif
The 10-day temperature anomalies look strikingly similar to the temperature anomalies for all the La Niña cases cited at the beginning of this thread (excluding 1985) when the AO averaged -0.1 or below for January:
http://img.photobucket.com/albums/v327/donsutherland1/JanNinaAO-01orbelowex1985.png
In sum, at least for now, there seems to be some support for the kind of monthly temperature departures that have occurred during past La Niña events in January with an ENSO Region 3.4 anomaly of -1 or below and an average monthly AO of -0.1 or below.
It looks like the first half of January will be average cold, but very little precip. In fact, the NWS has us below normal precip and average temps 14 days out from now.
ReplyDelete