Here's why it's been so cold

Here's why it's been so cold

The Mid-South has endured days of bitter cold with afternoon highs well below normal limits and overnight lows that have plunged into the single digits for many along with wind chills that have made it feel even colder.

The average high temperature during this period is 50 degrees with an average low of 33 degrees.

The cold temperatures of late are certainly not unheard of.

As a matter of fact, we experienced a similar cold snap January 5-8 of last year when highs only reached the mid 20s and 30s with lows that fell into the lower teens.

However, this round of cold has lasted longer, and it has had an impact on much more of the nation.

While no record temperatures were broken here, that hasn't been the case for other parts of the country where more than two thirds of the nation have been plunged into the deep freeze.

This week, NASA released a land surface temperature map from its Terra/MODIS satellite.

The map shows surface temperatures for Dec. 26 through Jan. 2 with areas along and west of the Rocky Mountains in blue where cold air has been in place and areas west of the Rockies in orange and red where warmer air has been confined.

The areas in blue have been inundated with pulses of cold, dense arctic air, plunging as far south as the Gulf Coast.

The jet stream has been displaced well south during that same period, keeping the pattern in place.

To the west, warm tropical air has migrated north bringing unseasonably warm and mainly dry conditions for the western state and as far north as Alaska, where record highs have occurred.

The Rockies have acted as a barrier keeping these air masses separated.

Having this data is very valuable to forecasters and meteorologist. It gives us a detailed look at large scale weather patterns and trends, and it helps when looking back at why certain patterns occurred.

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