Arctic Attacks in November

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The record low in Huntsville for today, November 20th is 10º F. That blows my mind! So, I started doing a little looking around, and that isn’t even the coldest record on the books for November. It actually dropped to 1º F on November 25, 1950 in Huntsville!

Here’s the surface map from that day:

You can get maps like that from the NOAA Library. It’s likely that there was some snow on the ground for temperatures to get that cold, but there is no formal record of snowfall in Huntsville on November 25, 1950.

We expect some Arctic air over the next few weeks, but it won’t even come close to rivaling this kind of late Autumn cold! You can always get the latest detailed extended forecast at WHNT.com/Weather!

It’s been a long time since we have had record-setting cold weather in late November. In fact, it has been 19 years since we had a single record low broken in the month of November; that occurred on November 7, 1993 when the temperature in Huntsville dropped to 25º F.

So what’s the deal? Why is November so mild?

Could it be evidence of climate change? It probably is.

I’ll go further than that, it is a likely result of a changing climate. Are you surprised that came from me?

Via Dr. Roy Spencer: http://www.drroyspencer.com

The above graph is taken from Dr. Roy Spencer’s blog; I have enormous respect for Dr. Spencer and Dr. John Christy at UAHuntsville and the work they do to get to the facts about climate data.

Climate has natural variability as you can see from the chart above. There was a very warm period in the Middle Ages (from around 500 AD to around 1400 AD); this data is not from airport temperature records like we have today. Instead, this kind of analysis comes from paleoclimatology:

Paleoclimatology is the study of climate prior to the widespread availability of records of temperature, precipitation and other instrumental data. NOAA is particularly interested in the last few thousand years because this is the best dated, best sampled part of the past climatic record and can help us establish the range of natural climatic variability in a period prior to global-scale human influence.

-NOAA

Back to Huntsville’s temperature record now: it was obviously much colder before the 1990s. In fact, most of the November record lows in Huntsville occurred prior to 1961 (22 of 30 records). There have only been 8 records set over the 50 years between 1961 and 2011. The two record lows in the early 90s were quite possibly a result of some short-term global cooling following the eruption of Mt. Pinatubo. Other cold periods like the late 30s and early 40s Here are the records and normals for Huntsville since 1907 (November only):

So our climate does change, and it has done so often in the past due to natural factors. An article from January in the UK Daily Mail does a good job explaining how there are differing opinions between some climatologists and NASA astronomers on how the solar cycle (sunspots, etc) could impact the climate here on Earth.  It’s definitely not a settled debate yet.

Another natural factor is volcanoes. There is a clear relationship between major volcanic eruptions and cooler temperatures. Mt. Pinatubo’s influence was one of the most recent examples, but there are many others that correspond to colder periods over the past two thousand years.

You can type anything like this into Google and come up with a thousand results that will tell you there’s a clear-cut reason for changes in climate. Some of them will show evidence that it’s mainly because of the Industrial Revolution and fossil fuels. Others will debunk those sources with some good science and research of their own.

Based on conversations with credible scientists that I know and trust, I’m not a proponent of AGW – anthropological (man-made) global warming. There is too much good science pointing to natural processes to claim that the world is ending due to a warming planet. I do believe we have some minor influence on the Earth’s over-all temperature, but that influence will probably be shown over the coming decades to be negligible. In other words, it may show up in highly-sensitive modeling and data sets, but the over-all impact will be almost zero.

The next 10-15 years will show us a lot about who is right and who is wrong.

-Jason
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