“Another weather model has joined the ranks of those predicting a colder than normal winter across a rather large portion of the country in coming months."
This is the Constructed Analog, or CA model from the Climate Prediction Center. It projects positive temperature anomalies to develop across the Bering Sea and Greenland areas, which may indicate positive height anomalies (high pressure) in those regions. For all intents and purposes, let's assume high pressure anomalies do exist in these two regions of positive temperature anomalies. This then leads to colder than normal temperatures flowing southeast from western Canada, spreading across the Plains, Midwest and even towards the Gulf Coast. This is actually not that far off from other forecasts made by other models, and this strengthens the argument for a colder than normal winter. 500 millibar height forecasts for the December-January-February period basically confirm the assumptions we made earlier in this post with the temperature anomalies. We see persistent positive height anomalies across the northern Pacific and Bering Sea. This is a very good sign for the chances of stratospheric warming events, which, if the atmospheric pattern is right, can allow for frigid air to move into North America. Multiple forecasts have been indicative of this positive height anomaly presence in the North Pacific, and the CA model's projection of this factor only aids in its credibility. We also see an elongated positive height anomaly swath across eastern Canada, Greenland and into northwest Europe. This is supportive of the negative North Atlantic Oscillation phenomenon, which permits a flow of cold air and enhanced coastal storm potential mainly in the Northeast, but the cold weather can spread across a wide portion of land east of the Mississippi. So what does all of this mean? The long range models seem to be coming together, suggesting that a cold winter may really be on the way."
Second Consecutive Frigid Winter Expected
See Andrew's summary - Saturday, October 11, 2014
“For temperatures this winter, I expect below normal anomalies to extend from the Northern Plains into the Deep South, and all points east. The Great Lakes, Northeast and New England areas may expect to experience well-below normal temperatures at times, as the ingredients are there for frigidly cold air to enter the North US in a similar fashion as last year”.
“Lastly, but definitely not least, the snowfall forecast. This forecast was the toughest to make, so bear with me as we navigate the uncertainty. I'm expecting below-normal snowfall for the Ohio Valley area, into the southern Midwest. This comes as a result of the weak to moderate El Nino expectation, which usually limits snowfall in this area. I'm watching closely for above-average snowfall in the Plains and Midwest, depending on how the Northeast Pacific and Western US regions evolve this fall and into the early winter. Around average snowfall is expected in the East US, with caution placed on the risk for big storms”.