We all had big expectations for Winter Storm Fern, but fortunately, it wasn’t as catastrophic as predicted. There are many factors that go into weather forecasting, but it does make us wonder what happened; or didn’t happen in this case.
Blame it on “the wedge”
The reason Winter Storm Fern wasn’t as bad for us here in Columbus and surrounding areas is due to what experts call a “weather wedge.”
A weather “wedge” is a nickname for a phenomenon called cold-air damming (CAD) and according to WTVM meteorologist Derek Kinkade, “it can creat[e] big temperature differences across the region.”
What is a weather wedge?
- Forms when a high-pressure system pushes into the Middle-Atlantic or Northeast.
- Winds around high pressure blow clockwise, carrying colder air southward.
- Cold air hits the Appalachian Mountains, which act like a dam.
- Cold air “leaks” south along the East Coast instead of crossing the mountains.
- This shallow cold air mass can reach north and east Georgia, plus parts of west Georgia and east Alabama.
- The shallow depth of the cold air sets up ideal conditions for ice storms when precipitation falls.
Why the forecasts sounded so dire
Meteorologists nailed the high-risk pattern , but models always wrestle with razor-thin margins. Fern’s cold air didn’t dig as deep into west Georgia, and that beefier warm nose aloft nudged the worst effects up toward Athens and Carolina borders.
Gov. Brian Kemp declared an emergency as a way to prepare for a situation that, thankfully, didn’t happen.
The weather we had vs. the predicted conditions
Early models painted a scary picture as Fern approached, but Columbus surface temps hovered near 32 degrees longer than expected, turning projected freezing rain into cold drizzle in spots…