Warming Trend and Another Arctic Plunge

Do not be fooled: November is never “normal.”

The words normal and average are interchangeable when talking about the climatology of an area. So, when you look at November “normals” of a high in the low-60s and a low in the low-40s, understand that those numbers are really the middle of the extremes.

November 2013 has been well-below normal by climatological standards.

Huntsville is 3.2ºF below the 1981-2010 average.
Muscle Shoals is 1.6ºF below the 1981-2010 average.
Decatur is 2.4º below the 1981-2010 average.

The warmest temperature this month in Huntsville has been 77 degrees; the coldest was Wednesday morning: 26 degrees.

Here’s where we are going for the next few days (more detail can be found at WHNT.com/Weather – we update the forecast multiple times a day).

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Surprisingly, this is what is really normal for November: temperature chaos! It’s been down, now we are headed back up a roller coaster hill only to drop sharply again on Monday night behind a strong cold front.

Check out the GFS temperature forecast for Huntsville early next week! Tuesday and Wednesday’s highs in the 30s? This is probably a bit too cold for reality, but it’s one of the tools we use for the extended forecast:

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It’s the back and forth weather pattern that gives rise to the ugly weather that November is known for. Friday is the 24th anniversary of the Airport Road Tornado, and although it’s been almost a quarter-century since that horrible afternoon, it is still the benchmark for the Fall severe weather season in this area.

Temperature chaos may bring some heavy rain and storms late in the weekend into early next week; a strong cold front moving into a much warmer, more humid air mass sets the stage for a chance of some storms. Will there be severe weather here in Alabama and Tennessee? It’s too early to tell…but it is something we have our eyes on.

The midday run of the GFS and this morning ECMWF (European) model are suggestive of at least a chance, but they aren’t very convincing.

Here’s the GFS output showing mean sea level pressure and 6-hour precipitation (that’s precipitation that fell in the 6 hour up to the time posted on the map):

That big low wrapping up around the Great Lakes is in a position where we have to be wary of it, but it’s far from a sure bet. There are a lot of pieces of the puzzle that aren’t visible now like instability, low-level shear, and even the true intensity of the entire system.

In short, we’ll be watching it…so be sure you check in with us through the weekend just in case there is a change in the appearance of this next round of wet, windy weather.

As a reminder, we’ve got ways to keep you in touch on your time, wherever you are:

WHNT.com’s Maps & Radar Page
Mobile Applications
Baron Saf-T-Net

-Jason
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