The relentless barrage of winter storms continues across the continental United States; Gemini is the name of the newest one. This storm will affect many of the same areas that experienced the effects of Cleon, Dion, Electra, and Falco — and more. This time we may see violent thunderstorms or even a tornado to go with snow, freezing rain, and sleet.
Winter Storm Gemini: True to Its Name
The Weather Channel has appointed itself arbiter of winter storm nomenclature, and has whimsically decided on mythical, astronomical, and zodiacal names for winter season 2013-14. Gemini represents a zodiacal sign under which those born supposedly possess multiple personalities. Gemini will be true to this tradition, producing heavy rains with warm temperatures in the south, and the possibility of tornadoes, and ice and snow to the north.
This Winter’s Weather Pattern
All of this weather is associated with a persistent weather pattern which features a dip (trough) in a robust jet stream over the U.S. A vigorous jet stream is associated with a strong temperature gradient (change of temperature); as of this writing, the temperature is below zero in North Dakota and in the 60s in Tennessee. This is a high potential energy state; we can expect frequent storms, which release this energy. Most of the action is concentrated at the boundary between the warm and humid air flowing north from the Gulf of Mexico and the arctic air moving south from Canada. This time, there will also be the threat of tornadoes associated with a dry westerly flow in mid levels moving over the humid air in the southern states.
What Areas Will Gemini Affect?
The warm air has made progress in its northward push, so much of the frozen precipitation will occur farther north than it did in storms Dion, Cleon, Electra, and Falco. This has also set up the likelihood of violent weather, including tornadoes, in the southern states where the warm air is firmly established and will be overlapped by the dry westerly flow. The zone of maximum probability of tornadoes stretches from Dallas to New Orleans to Memphis.
Some freezing rain may fall Saturday in the upper midwest, but the precipitation connected with this part of Gemini’s personality will be mostly either snow or rain. Where there’s freezing rain, the coating of ice will cause slippin’ and slidin’ of pedestrians and vehicles, but will probably not reach bough-breaking thickness. On Sunday, as the stormy conditions move east, there is a good chance of a significant icing event in central and northern New England, as the warm air streams northward over the frozen ground. Here, there may be as much as a half-inch of ice — enough to bring down tree limbs and power lines.
Winter Storms in 2013 an 2014: Looking Ahead
There is no indication from any of the computer models that the fast-flowing nature of the jet stream or its trough over the United States will change significantly in the next two weeks. High potential energy will still exist, as the warm and cold air masses trade thrusts and parries on the same battleground. The highest probability of nasty weather stretches in a band from Oklahoma and Texas to the midwest and New England, with a continuing possibility of tornado outbreaks in the southeast.