A once in twenty-five year Southeastern US snow and icestorm is upon us, as I post this blog. Precipitation in the form of snow, sleet and freezing rain is beginning to fall through portions of the SE. An area of low pressure is forming and will move along the Gulf Coast, over to the SE US Coast, and up the Atlantic Coastline, over the next three days. At the same time, a strong high pressure system to our north, will funnel very cold, dry air into our region. This cold air will support the formation of snow and ice in heavy amounts, for a large portion of the region, through Tuesday. As the low pressure system moves to the east and northeast, the upper air(5000 ft) temperatures will gradually warm, as warm air advection overrides the cold air at the surface. This will gradually transition the snow into sleet and then freezing rain and drizzle for all areas out side of Tennessee, and the mountains of Georgia and North Carolina. This transition should take place gradually, starting overnight from Atlanta south, in Georgia, and then moving slowing to the Northeast, as the day progresses tomorrow. The computer models are showing up to 1 to 1.25 inches of liquid equivalent. This translates to roughly 6-10 inches of snow and sleet for NE Georgia, followed by .10 to .25″ of ice accrual. Temperatures should drop gradually through the night, and with very low dewpoints, we should bottom out in the low to middle twenties. With the advection of cold, dry air from the Northeast, we should stay in the middle to upper twenties tomorrow, with periods of heavy snow and sleet up until around 1pm, transitioning to freezing rain and sleet, then freezing rain and drizzle, by tomorrow evening. Another aspect of this storm will be the danger from falling tree limbs, small or shallow rooted trees, and damage to power lines and equipment. In other words, the hardest hit areas could have major power outages. Expanding out some, Central areas of Mississippi, Alabama, Georgia and South Carolina look to have a quick burst of 1 or 2 inches of snow, then a quick transition to sleet and then freezing rain. These areas could potentially have a severe icestorm, with widespread power outages and trees down. Power outages in the areas that experience them, could last for some time, as we should experience very cold temperatures after the storm is finished. The computer models overestimate temperatures in these scenarios, as the snow and ice will reflect the radiation from the Sun, and our temps are likely to fall to as low as 5-10 degrees for lows on Thursday and possibly Friday. Please prepare for possible power outages and terrible road conditions, for potentially an extended period of time. Oh, yeah, models are showing the possibility of another major Winter weather event next Sunday/Monday. More on that later……………….
snoah47 on Severe Winter Storm to impact…