Monday, December 26, 2011

Mid January Arctic Blast?

Gary Lezak, the man who discovered the LRC, is indicating that an arctic blast of cold air is possible come mid January. We are investigating this, but at this time his confidence level seems fairly high. We are working to see if this may coincide with a possible break in the weather pattern.

December 26-28 Snow Event (Ohio Valley, Northeast Affected)

A low pressure system will be moving across the Ohio Valley and through the Northeast. We will be seeing this system be moving pretty quickly, but accumulations will be on the increase as we see a cold front moving southeast from Canada. This front will bring cold air right up against the precipitation. Much like how a cold front ignites heavy precipitation in the summertime, snowfall will increase right up against the front. Because we don't know how much influence this front will have on the precipitation, accumulations might be a little heavier than what we have shown right now.

UPDATED 2011-2012 Winter Forecast

For the rest of winter, we are expecting the east Coast to end up above normal, temperature wise. We find this likely, as the fall was very warm, and trends in fall can move into winter, which has happened this season. Additionally, no blocking has been present. Blocking involves a high pressure over Greenland, which enables cold air to move into the Northeast and push the storm track south, so that the Northeast is in a prime spot for snowstorms. That is not happening this year. This is due to stratospheric warming, among other things. Usually, the stratosphere will warm in the early days of winter and start up the snowstorms. However, the stratosphere has not been warming until the last couple of days. This means that the pattern change will take at least 2 weeks to take effect. Essentially meaning at least 2 weeks until a major snowstorm.
The Ohio Valley southwest-ward into the Southern Plains will be experiencing wet conditions. Ohio has already broken all-time records for rainfall. This is expected to continue through the winter, and when the pattern change occurs, we will be seeing big snowstorms cut through the Ohio Valley. I am expecting several, if not many, 'major' snowstorms once the pattern changes for the Ohio Valley.
Down in the far Southern Plains we see an area of dry conditions expected. This is due to the La Nina, but has been helped by a +NAO/+AO.
Far out west, cooler than normal conditions are expected.

Notes about the indices:
-NAO should average above normal for the winter, but will dip negative at least once the rest of the winter. When it does dip into a good negative, I can see a big snow hit the Northeast.
-AO is in the same boat as the NAO.

6-10 Day Outlook: 12/31/11 - 1/4/12

6-10 Day Temperature Outlook
The Climate Prediction Center is forecasting a high probability- possibly the highest confidence we have seen in the 6-10 day temperature outlooks- of above normal temperatures for the very heavy majority of the country. Every state in the continental US is forecasted to have above normal temperatures over the 6-10 day period, except for Florida, where some slightly below normal temperatures are forecasted.

Before you jump to the conclusion that this is Global Warming at its best, it's not. This is simply a weather pattern gone bad. The same bad weather pattern has delayed winter. And no, this bad pattern is not due to global warming.

6-10 Day Precipitation Outlook
Most of the country is forecasted to be below normal, precipitation-wise. It appears that the storm track will be displaced slightly more north, leading to above normal precipitation in the far northern reaches of the country. The Northwest may get in on some above average precipitation amounts.

UPDATED Winter Forecast will be released at 12:00 PM CST

Our updated winter forecast will be released at noon CST.