Tuesday, November 25, 2014

December 2-6 Potential Winter Storm

Another winter storm threat is on the horizon.

The image above shows forecasted 500mb vorticity values with superimposed 500mb height contours over Japan for November 26th, off the GFS model. In this graphic, we see a depression in the contours over Japan, as well as a swath of red positive vorticity values,  indicating the presence of a storm system. Using the Typhoon Rule, which states weather phenomena in Japan is reciprocated in the United States about 6-10 days later, we might expect a storm system to trek across the US in a December 2-6 timeframe.

The ECMWF model is already hinting at this potential storm, as the above frame shows a positively-tilted trough entering the Central Midwest on December 4th and 5th. The extent and intensity of snowfall remains in question, but for now, the possibility is certainly present.