Quick question on arctic cold fronts....

[Johnny]

I was just wondering....what is keeping these arctic airmasses from filtering into the Deep South? What would need to happen for us in the Deep South to get some good modified arctic air?

[AggieSpirit]

A big dome of high pressure in the southwest is keeping the really cold air masses from getting this far south. Northern jet isn't dipping down westward enough.

I am no meteorologist, but I think that is the reason why.

The extended forcasts show that the ridge will back off over the next week or so. When that happens, all you will need is a low to develop along the northern jet, and really cold air will filter in, because there is a whole bunch of really really cold air locked up in Canada and the snowpack is pretty solid now up north. But will it happen>?????? I at least hope so....elsewise, the bugs and pests will be a problem come spring time. We need a good really hard killing winter air mass down here to kill some fire ants and mosquitos.

Just gotta get that high pressure ridge out of the way.

[Stormsfury]

Also, the general pattern isn't directing the arctic fronts directly southward, but southeastward ... and primarily targeting the areas in the Northeast, and Mid-Atlantic, with some drainage into the Southeast ... the trough in the East is a broad longwave trough, and not the sharp ridge/trough couplet that can generally be associated with arctic blasts plunging southward ... (take for example, a Blue Norther).

SF

[Stormsfury]

And also noted in another thread, the SOI's swing about NEG generally lends credence to a more progressive pattern and indeed that may be realized soon enough ...

http://www.storm2k.org/phpbb2/viewtopic.php?t=22802