The Weather Channel has named the latest blast winter storm Hercules. There are signs that the storm brewing, now in its infancy, may grow up to be like the be-muscled man-god of Greek-Roman mythology for which it is named.
Conflicting Forecasting Models
The age of computer modeling of the atmosphere is in full swing. Greater computing power combined with more accurate measurements of wind and temperature allow computer-generated forecasts to have greater validity than ever; still, there are major differences among the various models and they are all occasionally wrong. Two of the most advanced models grow Herucles to, well, Herculean strength -while differing on placement and timing.
Weather: The American Model
The Global Forecast System (GFS), run by the US National Weather Service, produces forecasts that frequently overestimate the strength of storms, so we take its guidance with caution. The GFS insists that Hercules will strengthen rapidly and race eastward, becoming a major storm on the mid-Atlantic coast on its way out to the open Atlantic Ocean.
Storms: The European Model
The European Center for Medium-Range Forecasts (ECMWF), a consortium supported by 20 European countries, generally produces more conservative forecasts. Known as the European model, the ECMWF forecasts that Hercules will form in the northern plains, move eastward affecting the midwest, and re-develop as a classic nor’easter moving up the eastern seaboard.
Decoding the Forecast
There is certain to be a band of snow in the midwest, centered on Chicago. The snow will be enhanced by the lake effect, which can create locally voluminous amounts of snow when cold air blows across the much warmer waters of the Great Lakes. From here, the storm will likely move east and redevelop, dumping up to a foot of snow on Boston and areas further north. The air is cold enough that some ‘ocean effect’ snow, the equivalent of lake effect over the Atlantic Ocean, may enhance snowfall totals.
Hercules appears to be far enough north to spare Washington, D.C. any snowfall; New York could get just a few inches. But Hartford, Providence, and Boston may get a foot, while heaviest amounts will be in central New England.
As we ring out the old year and ring in the new, the meteorological ringtone isn’t changing. The weather pattern that has persisted for more than six weeks is still with us: The jet stream whizzes across the United States with a dip in the middle of the country. The steep temperature gradient persists as Arctic air ploughs south from Canada and warm, humid air surges north from the Gulf of Mexico. All the conditions are in place for yet another storm, perhaps as early as next week. The next storm’s name will be Ion.