Judah Cohen

Principal Scientist and Director of Seasonal Forecasting

Verisk Climate’s Atmospheric and Environmental Research Adds Winter Temperature Animation to Arctic Oscillation Blog

By Judah Cohen
December 3, 2014

We created a new animation that shows the observed evolution of temperature anomalies throughout the Northern Hemisphere landmasses based on snow cover alone. We composited daily temperatures (using a five day filter) of years with observed high Eurasian October snow cover minus low Eurasian October snow cover. The animation runs from September 1 through February 28. You can view it on the Arctic Oscillation blog toward the bottom of the page.

AER’s “amazingly accurate” winter outlook

By Judah Cohen
April 29, 2013

The AER winter forecast has now been correct for four years in a row (Read Press Release ). Even before that we had published a paper documenting that the AER model was the most skillful, e.g., accurate, winter seasonal forecast model that can be verified. Yet before every new forecast, winter or summer, there is great pressure to be correct and the need to validate the accuracy and usefulness ...

AER's Polar Vortex Forecast has Star Debut at AMS Annual Meeting in Austin

By Judah Cohen
January 16, 2013

Justin Jones and I spoke at the AMS annual conference in Austin Texas, as well as many others from AER. Justin presented on tropospheric precursors and stratospheric warmings while I argued that predictability of the winter forecast based on the scientific current state of knowledge is limited to October.

Sea ice was definitely “hot”, Dr. Judah Cohen of AER reflects on AGU'12

By Judah Cohen
December 13, 2012

I was not planning on attending AGU this fall in San Francisco but then received two invited talks; one on climate prediction and the other on how warming of the Arctic is impacting weather in the midlatitudes. Talks are very hard to come by at AGU, with 22,000 participants, so two invited talks seemed like an opportunity not to be squandered.

2012: The Year Without a Winter, Back to the Future?

By Judah Cohen
June 8, 2012

A hot topic of conversation this past winter was how mild and snowless this winter has been, especially compared to the past two winters along the Eastern Seaboard. And the mild winter certainly had people asking: is this what we can now expect from global warming?

Dr. Judah Cohen visiting UK Met Office/Hadley Centre in Exeter

By Judah Cohen
April 20, 2012

Five meteorology talks in 4 countries in 2.5 weeks. Dr. Cohen’s “great capitals of the world” tour.

Snow Advance Index: A New Tool for Predicting Winter’s Severity

By Judah Cohen
November 14, 2011

Snow Advance Index: A New Tool for Predicting Winter’s Severity Researchers at AER have developed a new Snow Advance Index that could greatly improve the accuracy of winter seasonal forecasts. Based on research and testing, this index for the first time can accurately predict the severity of the upcoming winter. What makes this discovery so significant is that advances in seasonal forecasting have remained elusive, and for much of the United States seasonal forecasts are no more accurate today then they were decades ago.

Predicting Future Energy Consumption

By Judah Cohen
November 16, 2010

Not only are greenhouse gases a major force that is driving global warming, but their impacts on temperature change is also now known to be greater than initially thought. On top of that, annual global temperatures are continuing to accelerate. We have determined that, based on the average of a set of complex atmospheric model projections, the temperature will increase in the United States in each of its regions throughout the first half of the twenty-first century in both winter and summer.