Wednesday, February 16, 2011

Winter Returns?

It's been two weeks since our last measurable snowfall and even with the "warm" temperatures most the area still has decent snow cover. As of 7:00 p.m. tonight I still have 9" inches of snow in my backyard and even more in my front yard on the north side of the property. I would guess that another 2" will melt tomorrow and 3"-4" on Friday, after that cold air returns for the weekend and snow cover will remain in places over 500 feet in elevation and also on north facing terrain.

In my last post I talked about the arctic oscillation (AO) switched back to positive and that is what has lead to this warming spell. I watch stratospheric warming very carefully now and I notice something happening over the pole. Its negative once again.

The black circle indicates a strengthening warming event in the stratosphere over the arctic.The perfect place for it as the cold air at the surface gets displaced to lower latitudes. Saturday will bring change as the blocking pattern over the pole begins to affect the current pattern. How you may ask? Take a look at the GFS for Monday night into Tuesday:

Keep checking back as I narrow down the specifics of the event. Hopefully we can get a good dump of snow out of this.

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