World Meteorological Organization
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Extreme Weather in parts of the world (Updated 14 February
2014)
Source: Japan Meteorological Agency Tokyo Climate Center
Parts of the world have witnessed a series of extreme weather conditions in the first six weeks
of 2014, continuing a pattern that was set in December 2013.
Much of the United States of America has experienced cold waves and major winter storms, whilst
California remains gripped by drought.
The United Kingdom has seen its wettest December-January period on record, with severe,
widespread and prolonged flooding. A combination of strong winds, storms and high tides caused
damage and flooding in other coastal areas of Europe. There has been unusually heavy snowfall in
the southern Alps.
Monthly mean temperatures were extremely high from eastern Mongolia to eastern China.
In the Southern hemisphere, Australia, Argentina and Brazil experienced extended heatwaves.
Throughout this period, national meteorological and hydrological services provided forecasts and
regularly-updated warnings.
Northern Hemisphere
United States of America
For much of January, the Eastern part of the United States experienced cold Arctic weather. This was
counterbalanced by warmer than average temperatures in the western part of the country, so that
overall, January temperatures were close to the 20th Century average, according to the U.S. National
Oceanic and Atmospheric Administration The first half of February saw major East Coast winter
storms, which caused significant disruption to transport and energy networks.
The U.S. National Weather Service said that on 7 January, every state in the lower 48 states had a
location that was below freezing. This has been linked to a phenomena called the Polar vortex. In the
winter a deep reservoir of cold air becomes established through the atmosphere over the Arctic
because of the lack of sunlight. This is usually held over high latitudes by the jet stream, a fast
moving band of air 10 km up in the atmosphere which drives weather. This year, a “kink” in the jet
stream allowed the reservoir of cold air to move southwards across the USA. A blocking pattern
meant it was locked into place, keeping severe weather systems over much of the Eastern United
States extending down to northeast Mexico.
This pattern kept Alaska unseasonably warm in January 2014, resulting in this January ranking as the
third warmest on record, according to NOAA. At Anchorage the average temperature for January of
29.4ºF (-1.2ºC) was the fourth-warmest on record—slightly warmer than the average temperature this
past January in Philadelphia and New York City.
The same high-pressure system was responsible for the intensification of the California drought,
depriving the state of much-needed precipitation from winter storms, which normally account for
about half the annual total precipitation. Observations collected during January indicate that the
extreme lack of precipitation during October through December 2013 intensified the deficit that had
developed during the previous two water years. At the end of January 2014, California was in
“exceptional” drought for the first time in the 15-year-old U.S. drought monitor.
Europe
The unusually cold weather in the Eastern USA coincided with severe storms in Europe, also linked
to a persistent pattern of perturbations to the jet stream.
There is a connection between the observed large scale temperature anomalies over the northern
hemisphere and the so-called planetary waves. These explain the observed atmospheric
disturbances in pressure and wind patterns which affected large geographical domains and resulted
in opposite temperature signals and different extreme precipitation features across the Atlantic.
For the United Kingdom, in particular, the series of winter storms has been exceptional in its duration,
and led to the wettest December to January period in the UK since records began. Heavy rains
combined with strong winds and high waves led to widespread flooding, coastal damage and
disruption.
There were more days of rain (23 days) for the UK in January than for any other month in a series
dating back to 1961. A large part of southern England received twice the average rainfall for January.
It was the windiest December for the UK in records back to 1969, based on the occurrence of winds
in excess of 69mph.
There was prolonged and widespread flooding in many parts of England, with dozens of flood
warnings (immediate action is required) and severe flood warnings (danger to life) being issued by
the Environment Agency.
Between 1 and 13 February, six depressions developed over the Atlantic, impacting particularly on
the UK and Ireland. A storm on 12 February caused wind gusts of 80 - 100 mph in some exposed
western areas of the UK. Ireland and a number of new wave height records were reported.
Gale force winds and high tides also caused severe coastal events and some damage along the
Atlantic coasts of France, Portugal and Spain during January and February. At the start of February,
Venice and other parts of Italy flooded due to a combination of high tides and strong winds.
Much of Europe saw unusually mild temperatures in the first six weeks of 2014.
Météo-France reported that France had the hottest January since 1900 (equal with 1988 and 1936).
For instance, temperatures on 9 January were 5-9 ºC above the January norm.
Germany reported the average national January temperature was 2.8 ºC above the 1961-1990 norm,
according to the Deutscher Wetter Dienst. In Spain, AEMET reported a monthly average temperature
of 2.0 ºC above the long term average
Much of Russia has witnessed very much above normal temperatures reaching +9°C anomalies
during the week of 29 Dec-4 Jan. For example Moscow temperature Thursday averaged 2°C while
January daily average temperature is -9°C.
Unseasonably warm temperatures also caused problems at the Sochi 2014 Winter Olympic Games.
Roshydromet reported that temperatures at 2,000 meters altitude in the Mountain Cluster (Krasnaya
Polyana) were 3-5 ºC on 13-14 February.
China
China witnessed a dray and warm January. Average precipitation was the lowest since 1987. Many
parts of China saw less precipitation by 50-80 percent than normal years, according to the China
Meteorological Adminstration. The average national temperature from January 1 to 27 was minus 3.9
ºC, the second highest after 1961.
Southern Hemisphere
Australia had its hottest year on record in 2013, with persistent and widespread warmth throughout
the year leading to record-breaking temperatures and several severe bushfires.
This trend continued into mid February 2014.
The Bureau of Meteorology of Australia said that a significant heatwave affected much of the central
and eastern interior of Australia over the New Year period in late 2013/early 2014.
This was followed by one of the most significant multi-day heatwaves on record affected southeast
Australia over the period from 13 to 18 January 2014. The major area affected by the heatwave
consisted of Victoria, Tasmania (particularly the western half), southern New South Wales away from
the coast, and the southern half of South Australia. Over most parts of this region, it ranked alongside
the heatwaves of January-February 2009, January 1939 and (from the limited information available)
January 1908 as the most significant multi-day heatwaves on record.
For the period 11 January to 9 February, a number of site records were set, including:
• Melbourne had seven 40ºC days; annual average is one day
• Adelaide had 11 days of 42ºC or above; annual average is one day
• Canberra had 19 days of 35ºC or above; annual average is 5.4 days
In Argentina, the period of unusual heat which started in December 2013 continued through January
and into February, especially in central and northern regions, with a number of local heat records
being set, according to Argentina’s National Meteorological Service. Parts of Brazil experienced the
hottest January on record. South Africa also witnessed a heatwave in mid-January.
The role of climate change
In response to commentary about the links between the January 8-9 cold snap and climate change,
President Obama's Science and Technology Advisor, Dr. John Holdren, had the following to say:
«If you’ve been hearing that extreme cold spells disprove global warming, don’t believe it. No single
weather episode can prove or disprove global climate change. Climate is the pattern of weather
geographically and over seasons. A growing body of evidence suggests that the kind of extreme cold
experienced by the United States is a pattern we can expect to see with increasing frequency as
global warming continues. «
«I believe the odds are that we can expect as a result of global warming to see more of this pattern of
extreme cold in the mid latitudes and some extreme warm in the far north.»
The UK’s Met Office issued the following statement:
“As yet, there is no definitive answer on the possible contribution of climate change to the recent
storminess, rainfall amounts and the consequent flooding. This is in part due to the highly variable
nature of UK weather and climate.
Nevertheless, recent studies have suggested an increase in the intensity of Atlantic storms that take
a more southerly track, typical of this winter's extreme weather. There is also an increasing body of
evidence that shows that extreme daily rainfall rates are becoming more intense, and that the rate of
increase is consistent with what is expected from the fundamental physics of a warming world.
More research is urgently needed to deliver robust detection of changes in storminess and
daily/hourly rain rates and this is an area of active research in the Met Office. The attribution of these
changes to anthropogenic global warming requires climate models of sufficient resolution to capture
storms and their associated rainfall. Such models are now becoming available and should be
deployed as soon as possible to provide a solid evidence base for future investments in flood and
coastal defences.”