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Terry’s Take: 3 indicators to watch for the winter ahead

Posted on: 9:55 pm, October 8, 2013, by

Terry Swails Weather Blog

Where’s winter? We’ve still had no frost and the tomatoes and peppers keep coming in the garden. Maybe this is the trend for the winter? While that possibility is still on the table, I highly doubt it. Here are 3 factors to watch which could have significant impacts on the winter ahead.
1. A weak El Nino, especially in region 3.4 and how it interacts with sea surface temps within region 1.0 of the Pacific Ocean.  A theory exists that the warmer 3.4 gets vs 1.0, the nastier the winter should be. Note on the graphics how going into December region 3.4 is forecast to be much higher that 1.0. Assuming it happens (risky) that argues for a tough winter east of the Rockies.

NINO 3.4 SST FORECAST

NINO 3.4 SST FORECAST

NINO 1.0 SST FORECAST

NINO 1.0 SST FORECAST

2. October snow cover is growing and as of today is significantly higher than this time last year. The October Snow Advance Index uses Northern Hemisphere snow cover anomalies to predict the Arctic Oscillation and United States temperatures in the following winter months. If snowfall anomalies are above normal, a negative Arctic Oscillation and cooler than normal United States is favored. In the same sense, below normal snow cover anomalies across the upper latitudes result in a positive Arctic Oscillation, which helps to prevent cold air outbreaks in the US. Generally speaking, winters go as snow cover grows in the month of October.

NORTH AMERICAN SNOW COVER

NORTH AMERICAN SNOW COVER

SNOW COVER THIS YEAR COMPARED TO 2012

SNOW COVER THIS YEAR COMPARED TO 2012

3. Last and not least, there is a correlation between wet Octobers in the eastern US. and colder, snowy winters in the central and eastern sections. The wettest years tend to have the toughest winters. I have posted the 240hr rain forecast off the Euro and you can see it maintains a wet pattern in the east the next 10 days.

10 DAY RAIN FORECAST FROM THE EUROPEAN MODEL

10 DAY RAIN FORECAST FROM THE EUROPEAN MODEL

These are 3 factors I will be watching with great interest over the next 3-4 weeks.