Cold weather returning?

[Mike Hollingshead]

http://www.rap.ucar.edu/weather/model/disp...hr156hr060hr180

I have been keeping an eye on western Canada and how above average it has been there for a long period of time now. The gfs model keeps inserting colder air the further out it gets, but when that time comes around it really never came to be.

The last couple runs have shown the highest signal of COLD air returning to Canada. I'm wondering if it is actually going to finally happen. At 60 hours it has temps above 30 in a large region up there. By 132 hours it is bringing in -30 temps...

I'm hoping against it as you know where that large cold pool is going to want to go...right down the Rockies into the central US. I keep thinking if we can keep that nasty stuff out of the US and out of the gulf our spring will be much better and earlier. We have to be ahead on some curve for gulf heating, don't we? I suppose none of this above average stuff will mean anything for spring severe weather if we get just one severe frontal passage into the gulf(one in 04 or 03 seemed to take 3 full weeks for the gulf to recover from). I wonder how likely it is this severe cold could just slip east and stay up in Canada. Likely all pointless to wonder about this far out, but I have found it interesting just how long western Canada has lacked severe artic air, which has allowed us in the central/northern plains to enjoy a winter without those 0-10 degree high days(minus a 3-4 day period in earlier December).

Thoughts?

 

[Robert Dewey]

NAO is tanking... It's probably going to happen.

It happens every winter that a big arctic outbreak occurs, I think it's just natural and probably won't affect things all the way in May too much (unless you're planning on chasing in February and March?). If this were mid April, I would be worried...

 

[mikegeukes]

North Atlantic Oscillation (NAO) Index
http://www.cpc.ncep.noaa.gov/products/prec...k/pna/nao.shtml

NAO
North Atlantic Oscillation - the NAO is a large-scale fluctuation in atmospheric pressure between the subtropical high pressure system located near the Azores in the Atlantic Ocean and the sub-polar low pressure system near Iceland and is quantified in the NAO Index. The surface pressure drives surface winds and wintertime storms from west to east across the North Atlantic affecting climate from New England to western Europe as far eastward as central Siberia and eastern Mediterranean and southward to West Africa.

NAO Index
This index measures the anomalies in sea level pressure between the Icelandic low pressure system and the Azores high pressure system in the North Atlantic Ocean.

When the NAO is in its is positive phase (+NAO), the northeastern United States sees an increase in temperature and a decrease in snow days; the central US has increased precipitation, the North Sea has an increase in storms; and Norway along with Northern Europe has warmer temperatures and increased precipitation.

When the NAO is in its negative phase (-NAO), the Tropical Atlantic and Gulf coast have increased number of strong hurricanes; northern Europe is drier, and Turkey along with other Mediterranean countries has increased precipitation. Source: NWS

Mike