An interesting comparison for the 1/7 storm is Dec 16, 2020 (left). The shortwave trough is quite similar to the 0z GFS (right), but there are prominent differences:

- Less downstream confluence in 2020
- Deeper antecedent cold airmass in 2020
- Farther south trough this time pic.twitter.com/39JekXvcjd

— Tomer Burg (@burgwx) January 2, 2024