Heavy Snow and Ice Threaten Portions of the East
By Jackson Dill January 10, 2018
Based on recent model data, we have updated our forecast for the storm, which will be impacting the Eastern U.S. from Thursday night through Saturday. This forecast may still change so it’s important to stay with WeatherOptics for the latest updates. This is because the model guidance continues to shift in terms of where exactly the center of low pressure will track. As an upper-level low moves over Texas, a new surface low will develop somewhere in the vicinity. This low will wreak havoc for portions of the country from the Mid-Mississippi Valley through the interior Northeast.
The storm in the Midwest winds down as it enters Canada, yet a new storm over the South will begin to takeover late in the day on Thursday. For most locations that will be dealing with this storm, which is the Eastern U.S., the precipitation will begin as rain and will either stay as rain, changeover to freezing rain, or eventually turn to snow. This is based on how far south and east the cold air from an Arctic high over the Central U.S. intrudes. So starting Thursday afternoon, a light rain will changeover to freezing rain from northern Illinois through northwestern Arkansas. The icing in this area will be minor because it will only last for a few hours, but any icing can cause travel issues if roads aren’t treated. Then as we get into Thursday night, rain will turn into freezing rain and eventually snow from the southern part of Lower Michigan southward through western Ohio, Kentucky, Tennessee, all of Indiana, south and eastern Illinois, northeastern Arkansas, southeastern Missouri, and northern Mississippi.
High Precipitable Water Directed At New England
Once the sun rises Friday morning, the storm will continue to track towards the Northeast. At this time, the center of the low pressure will likely be centered over the eastern Ohio Valley. During the morning hours, freezing rain is possible from portions of Ohio southward through central Kentucky and Tennessee and potentially as far south as extreme northern Alabama. Meanwhile to the west, after dealing with freezing rain, a moderate snow is expected from southeastern Lower Michigan through western Tennessee. To the south and east where the air is mild, rain showers and thunderstorms will be impacting the remainder of the Southeast region through the day on Friday. Meanwhile a steadier, light to moderate rain will come down in the Mid-Atlantic and much of the Northeast. We are concerned, especially in Southern New England, about the threat of flooding. Up to four inches of rain is forecast for this region, and that will fall on top of the significant snow cover. Many areas have between 6 and 18 inches of snow on the ground. The combination of heavy rain and melting snow due to that rain and warm temperatures may lead to flooding.
As we get into the afternoon Friday, the snow and freezing rain will begin to break out in western New York and Pennsylvania. To the west, the freezing rain will turn into snow for all of Ohio and the rest of Kentucky and Tennessee. Snow will work as far east as the Appalachians and as far south as extreme northern Georgia during the afternoon. Thankfully, Atlanta will only experience rain due to milder temperatures.
This storm will then turn into one mainly for the Northeast beginning Friday night. There will still be snow falling down the Appalachian Mountain chain and we’ll see the rain continuing to fall from Southern New England through the Carolinas. Meanwhile in the interior Northeast, the snow will be cranking. Heavy snow, which will not be from the Great Lakes in the form of lake-effect snow, is possible from western Pennsylvania up through western and Upstate New York. A line of freezing rain will also develop overnight from around northern Vermont through central Pennsylvania during the first half of Friday night. As cold air continues to work in from the north and west, that will push the line of freezing rain further south and east. Therefore, early Saturday morning, freezing rain is possible from central Maine through much of New Hampshire, into the Berkshires of Massachusetts, the northwestern hills of Connecticut, Lower Hudson River Valley, northwestern New Jersey, southeastern Pennsylvania, and potentially as far south as Washington, D.C.. Thankfully, the freezing rain will be brief, lasting between two to four hours for most locations in the Northeast that experience the freezing rain.
As we get into Saturday morning, the precipitation in Southern New England may change to freezing rain quickly and then snow. By this point, the uncertainty is high on how quick the freezing temperatures will move in while the precipitation is still falling. Another concern is a flash freeze in Southern New England and along the I-95 corridor. Once the rain or other precipitation type comes to an end, the freezing air will quickly move in and temperatures will drop like a rock. Therefore, roads and all surfaces may become icy even if freezing rain doesn’t fall. Otherwise Saturday morning, the snow will begin to dwindle across New York state while it still comes down at a moderate to heavy intensity in northern New England. By the early-afternoon, this storm will move into the Canadian Maritimes and we can say so long to this storm.
Lastly, the map below shows where freezing rain is possible. In the darker shade of pink, freezing rain is likely and there is a good chance it is significant. That area has the best chance for at least a quarter of an inch of ice.