A Day of Downpours in NYC

Torrential downpours drenched New York City yesterday.  In fact, the Big Apple received nearly a month’s worth of rain in just one day.

According to the National Weather Service, 3.02 inches of rain fell in Central Park.  Not only is that a new daily record, it is more than double the amount of rainfall the city received during the entire month of April.

After a stretch of twenty-five days with hardly any significant precipitation, yesterday’s rain was very beneficial for the area.  The rate at which it came down, however, caused a number of localized flooding problems.

The 20th Warmest Winter in the U.S.

The winter of 2012-13, in many parts of the United States, feels like it will never end.  Storm after storm has been rolling across the country producing a profusion of significant snow events.    All told, however, this meteorological winter (December-February) was actually warmer than average.

According to NOAA’s National Climatic Data Center, this winter season was the 20th warmest winter on record for the contiguous U.S.  Posting an average temperature of 34.3°F, the country as a whole was 1.9°F above its long-term norm.  For comparison, last winter (2011-12) was the nation’s fourth warmest.

It is interesting to note that eleven of the past fourteen winters in this country have been warmer than average.

 

2012: Warmest Year on Record for U.S.

Its official!  2012 was the warmest year on record for the contiguous United States.

According to the National Climatic Data Center, the average temperature for the country was 55.3°F, which is 3.2°F above the long-term norm.  It is also a full 1°F above the old record set in 1998.  While a single degree may not sound like much, it is actually a large departure.  Records usually only differ by a tenth of a degree.

As hot as it was last year, this new record does not come as much of a surprise.  2012 brought the United States a record warm spring in addition to its fourth warmest winter, third warmest summer, and an above average autumn.

In terms of precipitation, 2012 was the 15th driest year on record in this country.  The average precipitation total for the lower forty-eight states was 26.57 inches, which is 2.57 below normal.  This lack of rain brought on the worst drought this nation has seen in more than fifty years.  The dry conditions, in turn, helped fuel a destructive wildfire season.  More than nine million acres were charred nationwide this year – the third largest area on record.

While high temperatures and low precipitation dominated, 2012 was also a year of severe weather.  According to the US Climate Extremes Index, 2012 was the second most extreme year on record for this country.  As a whole, the nation experienced eleven natural disasters that each caused at least one billion dollars worth of damage.  These events included hurricanes Sandy and Isaac as well as several tornado outbreaks in the south and mid-west. What a year!

Fifth Warmest November for Planet Earth

November of this year was unseasonably cool along the east coast of the United States, including here in New York City.  Much of the rest of the planet, however, was exceptionally warm.

According to the National Climatic Data Center, November 2012 was the fifth warmest November on record for the entire globe.  Earth’s combined average temperature for the month – over both land and sea surfaces – was 56.41°F, which is 1.21°F above the 20th century average.  This November also marks the 333rd consecutive month that our global temperature was above its long-term norm.

While a certain amount of climate variability is natural, it is important to note that since record keeping began in 1880, our planet’s ten warmest Novembers have all occurred in the past twelve years.  In contrast, the ten coolest Novembers were all recorded prior to 1920.

Nov2012_Global_Temps

Image Credit: National Climatic Data Center

Weather History: 80 Years of Weather at Mt. Washington

On this date, October 15th, back in 1932, the Mt. Washington Observatory was founded in the White Mountains of New Hampshire.

Located at 6,288 feet above sea level, this weather station sits on the highest peak in the northeastern United States. Given this unique position, the observatory experiences some of the wildest weather on the planet. With an average annual temperature of only 27.3°F, it is not unusual to see snow in the summit region year round.  The mountain, however, is most famous for its winds. In fact, until recently, it held the record for the fastest wind gust ever recorded, 231 mph in 1934.  The new record of 253 mph was reported on Australia’s Barrow Island in 2010 during Cyclone Olivia.

Having personally made it to the summit of Mt. Washington twice, I can attest to its cold and blustery conditions – even during the summer months. It is a challenging environment, but nonetheless an amazing place.

Cloudy summit of Mt. Washington, NH:  6, 288 feet

Image Credit: The Weather Gamut

Third Hottest Summer for U.S.

Summer is a season known for high temperatures.  This year, however, they were more extreme than usual across much of the United States.

According to the National Climatic Data Center report released this week, Summer 2012 was the third warmest summer ever recorded in the lower forty-eight states. As a whole, the nation averaged a temperature of 74.4°F, which is 2.3°F above the long-term norm. Only the summers of 1936 (74.6°F) and 2011 (74.5°F) were hotter.

This summer’s exceptional heat follows both a record warm spring and winter.  In fact, 2012 – to date – has been this country’s warmest year on record.

Fourth Warmest July for Planet Earth

July of this year, as mentioned in a previous post, was the hottest month on record for the contiguous United States.  The heat, however, was not limited to this country’s borders.

The National Climatic Data Center (NCDC) reported today that July 2012 was the fourth warmest July ever recorded for the entire globe.  The planet’s combined average temperature for the month – over both land and ocean surfaces – was 61.52°F, which is 1.12°F above the 20th century average.  July 2012 was also the 329th consecutive month that our global temperature was above the long-term norm.

While heat dominated most of the planet last month, some areas, such as Alaska, Australia, and parts of Europe, posted below average temperatures.  Experts say these pockets of cooler conditions are normal, but note that they are shrinking as the Earth’s atmosphere warms overall.

The Hottest Month Ever in the U.S.

High temperatures are not uncommon for July in the U.S., but this year they were extreme.  July 2012 now marks the hottest month ever recorded in the lower forty-eight states.

According to NOAA’s monthly climate report, the country averaged 77.6°F this July.  That is 3.3°F above the 20th century average and breaks the previous record set during the Dust Bowl in July 1936.

Most of the heat last month was centered in the mid-west and central plains, where it fueled the region’s devastating drought. By the end of the month, more than 60% of the U.S. was in a state of moderate drought or worse.  These hot and dry conditions were ideal for wildfires, which scorched more than two million acres nationwide in July alone.

On the whole, this year has been exceptionally warm across the contiguous United States.  In fact, the period of January through July 2012 now stands as the warmest seven months this country has seen since modern record keeping began in 1895.

Third Warmest April for U.S.

Warmer than average temperatures dominated most of the United States this April.  According to NOAA’s monthly climate report released yesterday, this was the third warmest April on record for the lower forty-eight states.

As a whole, the country averaged a temperature of 55.7°F, which is 3.6°F above average. Most of the heat was centered near the Rocky Mountains and the southern plains, where over 300 daily high temperature records were broken.  No state, however, experienced below average temperatures.

Following this country’s warmest March on record and fourth warmest winter, April’s above average temperatures were not much of a surprise.  Experts attribute the intensity of the continued warmth to the persistent northerly track of the jet stream and a combination of climate change issues, both natural and man-made.

Record Warm Winter in the U.S.

It’s official! This was one of the warmest winters ever in the United States. According to NOAA, this meteorological winter (December-February) was the fourth warmest on record in the lower forty-eight. Registering an average temperature of 36.8°F, the country was 4°F above its long-term average.

Scientists say that a number of factors played a part in producing this unseasonable warmth.  To begin with, the Jet Stream, the boundary between warm southern air and cold arctic air, stayed well to the north this winter. As a result, mild conditions dominated the season and most of the country received below average snowfall. In fact, it was our third smallest winter snow cover in forty-six years of satellite record keeping.  Without snow to reflect the sun’s rays, the exposed ground absorbed solar energy, helping to perpetuate the warm conditions.

Two other significant factors in this winter’s story are La Nina and the North Atlantic Oscillation (NAO).  These powerful climate systems influence the shape and path of the Jet Stream.  La Nina, part of the larger El Nino Southern Oscillation (ENSO), brings cooler than normal water to the eastern Pacific Ocean. As a result, high pressure builds over the cool water and pushes the Jet Stream northward. NAO, the southern branch of the larger Arctic Oscillation, runs in positive and negative phases, depending on the pressure differences between Iceland and the Azores. A positive phase, like the one that dominated this winter, promotes a fairly straight path for the Jet Stream.  It also brings warmer than normal conditions to the eastern two-thirds of the U.S.

Given these constraints, the Jet Stream only managed to dip south a few times this season.  When it did, we were abruptly reminded that it was, in fact, still winter.  Those few cold blasts, however, never lasted very long. On the whole, it felt like a year without a winter.