The National
Oceanic and Atmospheric Administration (NOAA) has released its retrospective
on the weather for the year that just passed and, not surprisingly, there are
some interesting modern day records that have been broken.
Let's start
with this map that shows the difference from
average temperature by geographic area:
Every state
in the continental U.S. had an above average overall temperature for 2012.
A total of nineteen states broke new records and a further twenty-six states had
one of their top ten warmest years. The year started out with the fourth warmest winter out of the past 117 with
seasonal temperatures 3.9 degrees above the average for the entire 20th
century:
Please note
that the map shows how 2012's average winter temperatures compared to average
temperatures over the period from 1981 to 2010. Winter 2012 was warmer
than normal for one main reason; the winds of the jet stream which divide cold northern Arctic air from warmer southern air stayed further north than usual. This
impacted the distribution of precipitation with the eastern and western states
getting as little as 10 percent of normal precipitation and the central states
getting getting as much as 200 percent plus of normal precipitation.
New spring
temperature records were set with May being the second warmest May on record.
May's high temperatures, more than 3 degrees Fahrenheit above the
long-term average, contributed to the warmest 12 month period that the United
States has experienced since record keeping began in 1895. Here is a map showing just how warm May was
compared to historical norms for most of the United States:
The first
five months of 2012 set a new high temperature record for that time period with
temperatures a whopping 5 degrees above the long-term average. This excessive warming causes problems for the farming community; crops germinate early and insect and
weed pests follow shortly thereafter at a far earlier stage than would normally
be expected.
The hot dry
summer of 2012 was just that, very hot and very dry. The average
temperature in July 2012 was 3.3 degrees Fahrenheit above the 20th century
average, winning the award for the warmest month on record for the United
States. Here is a map showing how the central states suffered from
temperatures that were up to 8 degrees higher than normal for the month of
July:
Here is a map showing the drought conditions
that accompanied the hot weather in mid-July:
More than
1000 counties in 26 states were declared natural disaster areas, the largest
natural disaster area in U.S. history. With the
accompanying drought conditions, over 2 million acres of wildfires were
recorded during the month of July, the fourth highest since 2000.
Data for the
fall of 2012 shows that above normal temperatures and below normal
precipitation levels have been experienced by the continental United
States as a whole. Here is a preliminary map showing the warmer
and cooler than normal regions of the United States during the period from
September to November 2012:
Now, let's look
at the bigger picture. This bar graph shows that global mean annual
temperature from 1880 to the present:
Here is a
line graph showing the average annual temperature in the continental United
States from 1895 to 2010:
Over the
past century, the average annual temperature in the United States has risen by
1.2 degrees Fahrenheit per 100 years, roughly the same as the global average.
Climate is
defined as the meteorological conditions, including temperature, precipitation,
humidity, air pressure and wind, that characteristically prevail in a
particular region averaged over a long period of time. Basically, climate
is the average of all weather conditions. What we are seeing from this
report is NOAA's summary of 2012 weather. Eventually, all of the weather
experienced in 2012 will form part of the long-term average weather that will
make up climate. Eventually, as the warmer data is averaged into the long-term equation, we may be forced to admit that global
climate change is real, unfortunately, by then, it may be too late to do
anything about it.
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