Why is it so warm this December?

Palm trees blowing in the warm breeze. December so far has featured temperatures at record to near-record levels (File Photo) (Pixabay)

JACKSONVILLE, Fla. -- – December is the month of holiday decorations, spending time with family and friends, and the return of sweatshirt weather.

But so far this month, the sweatshirts have remained in the closet.

Record and near-record highs have been achieved the past several days, and more records may fall through the end of the week.

So far this month, the average high at Jacksonville International Airport has been 77°, well above the average high in early December of 69°.

It's been a warm December so far in Jacksonville.

We tied the record on Dec. 7, were one degree shy of the record on Dec. 6, and two degrees shy of the record on Dec. 3.

More records may fall Thursday and possibly Friday across the area, as the warmth remains in place.

Why so warm?

These very warm temperatures are a product of an unusually strong weather pattern across much of the country.

At the upper levels, a ridge of high pressure has been anchored across the eastern U.S., while a large trough has been stuck in the southwestern U.S.

The trough-ridge combination has allowed for above-average temperatures along the eastern and midwestern U.S., with below-average temperatures across most of the west.

A surface high is helping keep record highs across the area.

In addition, a surface high pressure has been in place west of the area. This has resulted in westerly winds, which often bring warm conditions to Northeast Florida and Southeast Georgia.

Dreaming of a toasty Christmas?

So how long will this warm spell last?

We will slowly stair-step down in the temperature department over the next several days.

The area of high pressure will exit to the east, and the upper-level ridge will also begin to pull away.

The result will be cooler highs in the 70s.

Cooler weather is becoming likely for mid-to-late December.

The latest 8-14 day outlook from the Climate Prediction Center has average to below-average temperatures across Southeast Georgia and Northeast Florida.

Week 3 and 4 Temperature Outlook

The average high for mid-December is around 67°.

As we push toward the holidays, the latest Week 3-4 Outlook is showing average temperatures.

Week 3 and 4 Temperature Outlook

This stretch would include Christmas Day and lead up to New Year’s Eve.

While December is off to a very warm start, cooler weather is likely on the way over the next 1-2 weeks.

About the Author:

David Heckard is The Weather Authority's Assistant Chief Meteorologist.