Polar Vortex Split: What It Means for US Cold Temperatures

Understanding the Polar Vortex

• ❄️ The polar vortex is a large, spinning cyclone of extremely cold air that circulates the Arctic, approximately 10 to 30 miles above the ground.
• ⚠️ Its primary function is to keep frigid Arctic air locked in its region.

How the Polar Vortex Affects US Weather

• 📉 When the polar vortex wobbles or splits, it allows Arctic air to spill southward into the US.
• 🗺️ The ultimate destination of this cold air depends on the specific disturbance and the path of the jet stream.

Types of Polar Vortex Disruptions

• ➡️ A displacement stretches the vortex, leading to shorter bursts of cold.
• 💔 A split breaks the vortex into two cores, which can result in longer and more persistent cold spells.

Expected Cold Snap

• 🥶 Following a stratospheric warming event in mid-February, the polar vortex has been disrupted, potentially leading to a split.
• 🌡️ This disruption could cause temperatures 20 to 30 degrees below normal across the eastern US.
• 🗓️ This prolonged cold could continue through early March and potentially last for a week or more.

Factors Influencing Cold and Precipitation

• 💨 Without sufficient moisture, the southward-moving cold air will result in bitterly cold temperatures but not necessarily snow or ice.
• ☀️ A brief warm-up is expected for much of the US in mid-February, but winter conditions are anticipated to return.