An area of low pressure tracked across southeastern Canada during the 12th, which brought an arctic front across the Mid Atlantic region late on the 12th. As this occurred, a strong area of high pressure located across central Canada built down into the Northeast, allowing very cold air to spill southward ultimately leading to what is known as cold air damming. This occurs east of the mountains down through the Mid Atlantic states. Meanwhile, a Pacific storm slammed onto the California coast during the 11th and as it moved eastward, a new area of low pressure developed across southeastern Colorado and the Texas Panhandle.