It will be a chilly and damp period of weather between Monday and Wednesday. For those eager to put up Christmas decorations ahead of schedule, this is the weather you hope for.

The reason? Cold air damming - a concept we've written about in the past.

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What is cold air damming?

Without the presence of the Appalachian Mountains, cold air damming wouldn't even be a thing. In a classic cold air damming event, you'll have high pressure anchored over the Northeast or even over areas like Quebec in Canada.

The northeast flow around it comes down the Mid-Atlantic, rising up the Appalachians. This creates a shallow layer of cooler air.

Cold air at the surface brought down from the northeast
Cold air at the surface brought down from the northeast (© WRAL)

In a case like Monday through Wednesday, the air thousands of feet above is warmer. This is a temperature inversion, and it is more difficult this time of year for any sun to poke through and break it up.

Warmer air thousands of feet above traps the chill at the surface
Warmer air thousands of feet above traps the chill at the surface (© WRAL)

Therefore, high temperatures will be well below average the next three days. Our highs will only be in the 50s.

High temperature forecast in North Carolina Monday
High temperature forecast in North Carolina Monday (© WRAL)

The average first 50° day in the fall happens on October 20th, but it didn't happen until mid-November in 2024.

Highs in the mid to upper 50s are more common in early December, though.

Highs in the 50s the next three days and how rare that is this time of year
Highs in the 50s the next three days and how rare that is this time of year (© WRAL)

How can this lead to more coastal storms?

This time of year, the Gulf Stream is significantly warmer than the cold air that's dammed into North Carolina. This temperature difference can be referred to as "baroclinic instability," which becomes a favorable zone for storm development.

Coastal storms happen more often when we're colder than usual on land
Coastal storms happen more often when we're colder than usual on land (© WRAL)

This is part of why we've seen several coastal lows in recent weeks.

It is also why Nor'Easters are most commonly seen in September through April.

What is a Nor'Easter?
What is a Nor'Easter? (© WRAL)

We also wrote about those recently - during the last Nor'Easter that slammed the Outer Banks.


Have questions about the weather and how it works?

Send me an email with the subject line 'Ask the Meteorologist:' to cmichaels@pugongyingbo.com.