History-WX
The arctic air mass as a 3D body (potential temperature below 280 K, core below 266 K), Jan 25 – Feb 20, 2021, 6-hourly from ERA5 — from staging over Canada to the Texas ice storm and the deep freeze. The ground shows 2-meter temperature. Drag to rotate. Keys: S cities · D draw · 1/2/3 color · C clear · L Deutsch.