Friday, 16 November 2012

Analogs and Winter Thoughts

The 11 day analogs turn the eastern part of north america frigid for december. I feel quite confident in a cold month with the euro weeklies, analogs and GFS ensembles showing very cold signals.

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Those decembers in those years:
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Right now my top 5 analogs are 1968-69, 2009-10, 2003-4 and 1962-3. This is because of the blocky patterns in those years which we have already seen taking place this year. A lot of december blocking is shown on the euro weeklies especially in week 3 and 4 of december. Even thoughts 2009-10, 1968-69 and 1962-3 were moderate el nino's I feel that the overall pattern shares similarities to our upcoming winter. 2003-4 was a la nada winter which had a snowy december and very cold january with less snowy conditions. February was near normal temperatures and below normal precip similar to january. Heres what the years looked like together by month.
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Looks like interesting times ahead but right now i feel most confident about a cold december and first half of january. By the end of winter if the SST's cool around greenland due to the cold air coming down from the arctic that could cause a much warmer second half to winter. This has happened before but is still uncertain and is a good reason to continue to watch the SST's which right now are almost ideal for cold and snow. The beginning half of winter may be very interesting but enjoy it while it lasts. We are already seeing evidence of this with two major east coast storms already. Current SST's have the warm Atlantic tripole which is a cold signal, a cool pool NW of hawaii which is another cold signal and third the warmth centred to the west in the enso regions is a cold signal in the east. Models face cool pool NW of hawaii but drift warm pool closer to west coast, breaking down negative PDO pattern some which will promote more ridging off the west coast.
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