Really Exciting Weather
The weather in the middle latitudes so far this winter has been exciting to say the least. Let's take a look at some places:
United States east of the Great Plains: After an unusually warm November, December and the first half of January, winter came back with a vengeance. First, let's rewind to the warm weather. November, December, and the first half of January were very, very, very warm. Temperatures crossed 20 degrees Celsius in Philadelphia on 7 days in November (including on the last day), 2 days in December and a day in January (topping out at 22 degrees on January 6, a record high for that date).
It even led weather speculators in the media to contemplate the chances of a snow-free winter, saying that if Central Park were to go through winter without seeing a single flurry, it would be the first time it happened in 150 years of record keeping. In Philadelphia, I noticed trees blooming across Drexel's campus in December and I wouldn't blame them. The phrase on everyone's mind was "global warming."
Then once in late January and again in early February, the jet stream dipped south and a massive blast of Arctic air came down from central Canada onto the U.S. mainland. Philly saw the mercury fall to -12 degrees on January 26 in the first Arctic blast, warm briefly, and then plummet again to -12 degrees on February 5 and 6 and -11 degrees on February 7. This time, the warm up is going to be a lot slower than last time (today's low is expected to be -9 degrees and tomorrow's and the day after's low will be -8 degrees). Compare that to average lows around this time of year of around -3 degrees, we're talking 5 to 10 degrees below average. By the way, the wind chill made it seem like -20 degrees in Philly in the past few days (am I glad I'm currently in Bangalore where the day time highs are around 29 degrees and night time lows around 16 degrees).
Chicago meanwhile saw its coldest day in 10 years when the mercury dropped to -20 degrees or lower on February 3, 4, 5 with the coldest night (Feb 5) seeing a low of -23 degrees Celsius. I can only imagine what the wind chill must have been over there (probably somewhere close to -30 degrees or so).
Anyway, this very unusual winter pattern (prolonged unseasonably warm weather followed by a massive Arctic blast) has created quite a volatile combination in the Great Lakes region. Normally, moderate cold waves pass over the Great Lakes in late November and December, causing Lakes Erie and Ontario to freeze over gradually and causing moderate lake effect snow on the lake shores of Ohio and New York. When the truly Arctic blasts come in January and February, the lakes are usually mostly frozen over.
This year, the lakes had no ice on them through the middle of January. When the Arctic blasts came, the cold, dry polar air readily absorbed moisture from the relatively warm lake surface as a dry sponge would. When this reached the other side, this has resulted in staggering amounts of lake effect snow, particularly in New York state off Lake Ontario (I guess because Lake Erie is shallower and more of it would have frozen in the first Arctic wave in late January).
http://www.msnbc.msn.com/id/17042993/?GT1=9033
Parts of New York have received up to 60 inches (~150 cm) of snow in as little as 24 hours with snow sometimes falling at the rate of 5 inches (12.7 cm) per hour. The event is not all said and done yet, but some places are expected to break the 100 inch (254 cm) mark before the proverbial fat lady sings.
While people have readily associated the warmer months with potential climate change, not many would associate these Arctic blasts with global warming. But they may be associated after all. One of the theories regarding global warming suggests a slight increase in temperatures but with a greater number of extremes.
For example, consider Anytown, America. In a normal winter (90 days), Anytown, America sees low temperatures of 20 days below -10 degrees Celsius, 50 days between -10 degrees Celsius and 0 degrees Celsius, and 20 days with low temperatures greater than 0 degrees Celsius. The average low temperature for winter is -5 degrees Celsius.
According to this theory of climate change, the average low temperature would shift by some amount like 2 degrees warmer to -3 degrees Celsius, but you would see something like 30 days with low temperatures below -10 degrees Celsius, 40 days above 0 degrees Celsius and 20 days with low temperatures between -10 degrees Celsius and 0 degrees Celsius. It's a scenario where extremes of cold and warm dominate with what used to be considered "normal" hardly being seen anymore.
It is of course one of many theories of what could happen and events of the winter of 2006-07 seem to go along with this. But next winter could follow a completely different theory. I'm not even saying that current weather is an indication of climate change, since I only have detailed knowledge of what's going on in the eastern United States. All I'm saying is that even this cold snap could be a consequence of climate change, according to one of the theories. I'll leave it up to the climate scientists to calculate average global temperature and count the cost of severe / freakish weather.
Speaking of freakish weather, here's what happened elsewhere in the world, briefly:
United States Rockies and West: While the eastern two-thirds of the country basked in unseasonably warm weather for much of November, December and the first half of January, the west shivered. In December, Los Angeles saw low temperatures approach the freezing mark, San Francisco saw a few snow flurries, and Denver saw snow storm after snow storm wallop it.
And January in California has been more or less seasonal as far as California, but it has been unusually dry. This is strange because 1) it is the rainy season. Also 2) some people have proposed that this is an El Nino year, which explains the warm conditions across much of the U.S. This could be true, but El Nino years are usually unusually wet for California, while much to the contrary, it has been unusually dry.
Europe: Europe was unusually warm through much of December and January, leading to a feverish crescendo over there to do something on climate change. Then in the third week of January (a few days after I passed through London on my way back to India), England was hit by a massive storm that created gale force winds across the island tearing down trees and roofs, canceling flights from airports, and battering the coasts with massive waves.
Subsequent to this, England seems to be hit by a freakish snow storm. An unexpected storm combined with some unusually cold air seems to have provided a wide swath of snow about 100 miles wide stretching diagonally down from northwestern Wales through southeastern England. Many major English cities have seen about 4 inches of snow (~10 cm) and portions of England could top 6 inches (~15 cm). While this number seems minuscule compared to what's happening in upstate New York, we have to remember that England usually doesn't get snow and even if it does, it's no more than a light dusting. The English are woefully unprepared to handle even a very modest snowfall such as this and this latest bout of freak weather is causing a lot of headaches on the other side of the Atlantic as well.
Meanwhile, Moscow had to cancel its ice festival this winter since the weather was too warm and the ice was melting away. In January, when Moscow usually averages about -9 degrees Celsius in January, Moscow saw high temperatures above freezing for the first 22 days of January, topping out at 8 degrees on January 11, about 14 degrees above average.
Asia: In Beijing, cherry trees are currently blooming. Beijing only saw one day in January when the high temperature dropped below the freezing mark (the average high temperature for January) and topped out at 8 degrees on January 17 and January 29. Unlike in Europe and North America, February has not seen a return to normal yet in China. Temperatures reached 12 degrees on February 3 and 13 degrees on February 6. Over the next ten days, temperatures are expected to cross the 10 degree mark on 5 days. The average high in Beijing for this time of year is 3 degrees. Temperatures are expected to cross that mark on every single one of the next ten days.
I wish I had as much detailed information about the rest of the world as I do about the eastern U.S. Somewhat worrying, but at least no one can complain that the weather has been dull, not even England, perhaps the home of monotonous weather.
United States east of the Great Plains: After an unusually warm November, December and the first half of January, winter came back with a vengeance. First, let's rewind to the warm weather. November, December, and the first half of January were very, very, very warm. Temperatures crossed 20 degrees Celsius in Philadelphia on 7 days in November (including on the last day), 2 days in December and a day in January (topping out at 22 degrees on January 6, a record high for that date).
It even led weather speculators in the media to contemplate the chances of a snow-free winter, saying that if Central Park were to go through winter without seeing a single flurry, it would be the first time it happened in 150 years of record keeping. In Philadelphia, I noticed trees blooming across Drexel's campus in December and I wouldn't blame them. The phrase on everyone's mind was "global warming."
Then once in late January and again in early February, the jet stream dipped south and a massive blast of Arctic air came down from central Canada onto the U.S. mainland. Philly saw the mercury fall to -12 degrees on January 26 in the first Arctic blast, warm briefly, and then plummet again to -12 degrees on February 5 and 6 and -11 degrees on February 7. This time, the warm up is going to be a lot slower than last time (today's low is expected to be -9 degrees and tomorrow's and the day after's low will be -8 degrees). Compare that to average lows around this time of year of around -3 degrees, we're talking 5 to 10 degrees below average. By the way, the wind chill made it seem like -20 degrees in Philly in the past few days (am I glad I'm currently in Bangalore where the day time highs are around 29 degrees and night time lows around 16 degrees).
Chicago meanwhile saw its coldest day in 10 years when the mercury dropped to -20 degrees or lower on February 3, 4, 5 with the coldest night (Feb 5) seeing a low of -23 degrees Celsius. I can only imagine what the wind chill must have been over there (probably somewhere close to -30 degrees or so).
Anyway, this very unusual winter pattern (prolonged unseasonably warm weather followed by a massive Arctic blast) has created quite a volatile combination in the Great Lakes region. Normally, moderate cold waves pass over the Great Lakes in late November and December, causing Lakes Erie and Ontario to freeze over gradually and causing moderate lake effect snow on the lake shores of Ohio and New York. When the truly Arctic blasts come in January and February, the lakes are usually mostly frozen over.
This year, the lakes had no ice on them through the middle of January. When the Arctic blasts came, the cold, dry polar air readily absorbed moisture from the relatively warm lake surface as a dry sponge would. When this reached the other side, this has resulted in staggering amounts of lake effect snow, particularly in New York state off Lake Ontario (I guess because Lake Erie is shallower and more of it would have frozen in the first Arctic wave in late January).
http://www.msnbc.msn.com/id/17042993/?GT1=9033
Parts of New York have received up to 60 inches (~150 cm) of snow in as little as 24 hours with snow sometimes falling at the rate of 5 inches (12.7 cm) per hour. The event is not all said and done yet, but some places are expected to break the 100 inch (254 cm) mark before the proverbial fat lady sings.
While people have readily associated the warmer months with potential climate change, not many would associate these Arctic blasts with global warming. But they may be associated after all. One of the theories regarding global warming suggests a slight increase in temperatures but with a greater number of extremes.
For example, consider Anytown, America. In a normal winter (90 days), Anytown, America sees low temperatures of 20 days below -10 degrees Celsius, 50 days between -10 degrees Celsius and 0 degrees Celsius, and 20 days with low temperatures greater than 0 degrees Celsius. The average low temperature for winter is -5 degrees Celsius.
According to this theory of climate change, the average low temperature would shift by some amount like 2 degrees warmer to -3 degrees Celsius, but you would see something like 30 days with low temperatures below -10 degrees Celsius, 40 days above 0 degrees Celsius and 20 days with low temperatures between -10 degrees Celsius and 0 degrees Celsius. It's a scenario where extremes of cold and warm dominate with what used to be considered "normal" hardly being seen anymore.
It is of course one of many theories of what could happen and events of the winter of 2006-07 seem to go along with this. But next winter could follow a completely different theory. I'm not even saying that current weather is an indication of climate change, since I only have detailed knowledge of what's going on in the eastern United States. All I'm saying is that even this cold snap could be a consequence of climate change, according to one of the theories. I'll leave it up to the climate scientists to calculate average global temperature and count the cost of severe / freakish weather.
Speaking of freakish weather, here's what happened elsewhere in the world, briefly:
United States Rockies and West: While the eastern two-thirds of the country basked in unseasonably warm weather for much of November, December and the first half of January, the west shivered. In December, Los Angeles saw low temperatures approach the freezing mark, San Francisco saw a few snow flurries, and Denver saw snow storm after snow storm wallop it.
And January in California has been more or less seasonal as far as California, but it has been unusually dry. This is strange because 1) it is the rainy season. Also 2) some people have proposed that this is an El Nino year, which explains the warm conditions across much of the U.S. This could be true, but El Nino years are usually unusually wet for California, while much to the contrary, it has been unusually dry.
Europe: Europe was unusually warm through much of December and January, leading to a feverish crescendo over there to do something on climate change. Then in the third week of January (a few days after I passed through London on my way back to India), England was hit by a massive storm that created gale force winds across the island tearing down trees and roofs, canceling flights from airports, and battering the coasts with massive waves.
Subsequent to this, England seems to be hit by a freakish snow storm. An unexpected storm combined with some unusually cold air seems to have provided a wide swath of snow about 100 miles wide stretching diagonally down from northwestern Wales through southeastern England. Many major English cities have seen about 4 inches of snow (~10 cm) and portions of England could top 6 inches (~15 cm). While this number seems minuscule compared to what's happening in upstate New York, we have to remember that England usually doesn't get snow and even if it does, it's no more than a light dusting. The English are woefully unprepared to handle even a very modest snowfall such as this and this latest bout of freak weather is causing a lot of headaches on the other side of the Atlantic as well.
Meanwhile, Moscow had to cancel its ice festival this winter since the weather was too warm and the ice was melting away. In January, when Moscow usually averages about -9 degrees Celsius in January, Moscow saw high temperatures above freezing for the first 22 days of January, topping out at 8 degrees on January 11, about 14 degrees above average.
Asia: In Beijing, cherry trees are currently blooming. Beijing only saw one day in January when the high temperature dropped below the freezing mark (the average high temperature for January) and topped out at 8 degrees on January 17 and January 29. Unlike in Europe and North America, February has not seen a return to normal yet in China. Temperatures reached 12 degrees on February 3 and 13 degrees on February 6. Over the next ten days, temperatures are expected to cross the 10 degree mark on 5 days. The average high in Beijing for this time of year is 3 degrees. Temperatures are expected to cross that mark on every single one of the next ten days.
I wish I had as much detailed information about the rest of the world as I do about the eastern U.S. Somewhat worrying, but at least no one can complain that the weather has been dull, not even England, perhaps the home of monotonous weather.
posted by Vivek at 9:02 AM
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