From the ABC 7 Weather team

Not the hottest ever; A detailed look into the heat of 2012

January 10, 2013 - 11:00 AM
Text size Decrease Increase

2012 ranked as the hottest year on record in the contiguous United States, but there's a little more behind the heat.

This article by the New York Times is something that drives me crazy, and I will wager the majority of my colleagues in the broadcast meteorology community feel the same way. Titled, "Not Even Close: 2012 Was Hottest Ever in U.S.," the article highlights the fact 2012 had the highest average temperature since accurate records have been maintained. But the headline hysterically evokes the notion it has never been this warm in the history of the planet. The data itself is correct as provided by the National Climatic Data Center but the headline writer, for the Times, based the headline on favorable media opinion rather than scientific fact. A much better headline is penned by NOAA, "By a wide margin, 2012 was the United States’ warmest year on record", found here (Thanks for the find Brad Panovich).

Related: 2012 Hottest on Record in U.S.

2012 did blow away the previously warmest year on record with an average temperature of 55.3 degrees. The warmest year previously was 14 years earlier in 1998 with an average of 54.3 degrees. The coolest year on record is 50.1 degrees set back in 1917. The records date back to 1895, which gives 117 years of data. Here lies the problem, with 117 years of data apparently stretching to the beginning of time.

2012 Statewide Ranks

Now let me go ahead and state a few things. I do believe the weather has warmed over the past years, but I'm not completely sold on ALL of the ideas and theories behind the global warming argument. Having said that, I'm not a climate scientist and I didn't even take a climate course while majoring in meteorology at North Carolina State University. Weather forecasting is my passion and that is what drives me as a scientist. Do I think climate should be carefully studied to determine if it could predict weather in the future? Absolutely.

I got the idea for the blog while on a conference call with NCDC when they were answering questions for reporters across the country. These reporters were from the AP, NYT and other major news outlets that give the majority of U.S. citizens their daily news. The problem is, almost every one of them asked a question trying to relate 2012 to global warming. At ABC 7, we wrote our own blog on it, and there are some very impressive statistics. We left out the mention of global warming as this brings up far too many questions that even the climate scientists at NCDC tried to avoid answering over the phone.

Here are some climatological tidbits about 2012 you may not of heard nor seen reported, as well as some interesting things to think about given this latest analysis.

The fact is this climate report was only for the lower 48 states...the contiguous states. The 2012 national temperature analysis doesn't include Alaska, whose size alone spans nearly a third of the United States. Don't worry, I have included a size comparison below so you can understand the vast size of Alaska compared to the continental U.S. I mention this because Alaska experienced its 11th coolest year on record. A span which includes over 95 years of data. January was the coldest on record. It was a whopping 14 degrees below average! Another fact absent from almost all reporting that I've seen is that Alaskans, state-wide, experienced below average temperatures during every season...summer, fall, winter and spring.

Alaska/U.S. Size Comparison

Here is something else I bet you didn't know. The 2012 hurricane season featured only one major hurricane. Hurricane Michael was a category 3 storm for a period of only 6 hours. This is the lowest number of major hurricanes in a season since 1997. The season was still the 3rd busiest on record, however, with an above normal ACE index as well as two storms that formed in May.

Hurricane Sandy Track

Severe weather in 2012. As far as tornadoes were concerned, 2012 was below average. It very well may have been the slowest year for tornado activity since 2002. And if the final numbers total below 934, it could be the slowest since 1989, which recorded 856 tornadoes. I included hurricane and tornado numbers as people often mistakenly try to relate hurricane intensity or severe weather outbreaks to global warming. It is quite interesting that during the hottest year on record, we experienced an unusually mild tornado season and such a low number of intense hurricanes. Wouldn't the unprecedented heat naturally cause increased numbers of tornadoes and more intense hurricanes. Research doesn't always back those hypothesis up, which is why this important topic continues its need for study.

March 2-3 Tornado Outbreak

When we have these really warm seasons and years I wonder if urban growth, resulting in urban heat islands, might be a cause of these warmer temperature readings in the climate data. I researched the record maximums and the record high minimums from 2012 at Reagan National Airport. There were 7 record maximums through the year and an astounding 15 record high minimums. A record high minimum is the warmest overnight low temperature for a date on record. For example, the LOW temperature was a record 82 degrees on July 7! This makes me think that some of this increase in temperature may be due to the vast size of our city centers, which can retain heat much better than they could just 10-20 years ago. I do not have compelling research to back up this observation. I have lived in the D.C. area my entire life and I know just how much the landscaped has changed. An article in the December 2012 Bulletin of the American Meteorological Society does focus on Local Climate Zones in Urban Temperature Studies which may help future climate records.

A quick look at the climate normals, means and extremes for Reagan National shows from 2000 to present, there have been only 21 record maximums, while there have been 41 record high minimums for the summer months. Dulles Airport shows 37 record maximums, with 61 record high minimums since 2000. BWI Marshall was the opposite however, with 23 record maximums and only 8 record high minimums. Think about it, there has been heavy urbanization around Dulles over the past 10 years but not nearly as much around BWI Marshall.

Record Maximum's and High Minimums for the Summer Months

I would be very interested to see a temperature data set located outside of major cities, to see if these dramatic spikes in temperatures, such as the one for the Nation through 2012, still occur, or if this data is beginning to be skewed by these ever expanding heat islands. This would allow for a more complete understanding of whether the trend of increasing annual temperatures is limited to or just more pronounced in major urban centers compared to more rural areas.

I have heard from sources that an algorithm is used to adequately counteract the warm bias due to the heat island effect, but have read in that BAMS journal article that the "urban-rural classification" which is used has "suffered critically". I have a inquiry into NCDC to ask of their current practices and will give an update when I receive a response.

Urban Heat Island Effect

2012 was not only a year of excessive heat but one of excessive drought, as well. Can we predict the certainty that 2013 will be a repeat of 2012? No. But given the current trend, I would say yes. Does that mean I believe we are in an uncontrollable, upward sprial of global warming? No. I think it means we are in a period of warmer temperatures and we would be better served to throttle back on opinions and throttle up on facts. And fund more research.

Thank you to the ABC 7 Weather Team including Doug Hill for his edits and everyone else for their insights.

Short URL: http://wj.la/VPVbFq
comments powered by Disqus