Are global climate changes already affecting local weather patterns?

Meteorologists at the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center today released the latest U.S. seasonal outlook and reiterated once again this winter is likely to be warmer than the 30- year norm over much of the nation.

Are we likely to hear more reports like this in the future? Are winters getting warmer and summers drier, or are these conditions we have experienced for the past several years an anomaly?

What the data tells us

Based on data from NOAA's National Climatic Data Center and stated in their annual report, the 2006 average annual temperature for the contiguous United States was 55 degrees, marking a 2.2 degree increase above the mean 20th century average, making 2006 one of the warmest years on record.

A contributing factor to the unusually warm temperatures throughout 2006 is the long-term warming-trend, which has been linked to the increase in greenhouse gasses, the report said.

NOAA's Climate Prediction Center shows that temperatures in West Virginia have increased between 0.10 to 0.25 degrees per decade since the trend began in 1976. This is based on data collected between 1941 and 2005.

During the same time period, the data shows precipitation in West Virginia has increased between 1.0 and 1.5 inches per decade.

A climate model run on supercomputers by scientists at Purdue University in 2005 predicts dramatic changes over the next 100 years. According to the results of the modeling, summers will be longer and hotter and winters will be warmer and shorter.

Imagine the weather during the hottest two weeks of the year. The area could experience temperatures in that range lasting for two months by the end of the century, said Noah S. Diffenbaugh, the team's lead scientist.

A report published by NASA on January 16, said: Climatologists at the NASA Goddard Institute for Space Studies in New York City have found that 2007 tied with 1998 for Earth's second warmest year in a century.

The eight warmest years in record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990, the report said.

How experts see it

Meteorologist and WUSA TV 9 weather man Topper Shutt agrees that the trend over the last few years has been for decreased snowfall and more ice storms. He also agrees that wind velocities have generally increased.

However, it is certainly

not global warming, Shutt

said.

Variations in the paths of jet streams and the phenomena know as El Nino and El Nina have perhaps had more effect in the short term than global warming.

But over the last four winters, snowfall amounts have decreased while ice storms have increased, along with stronger wind velocities.

What seems unusual in the short term may be normal over the long term, said Donovan Kelly, a part time Morgan Countian who is retired from the U.S. Geological Survey.

I think there is plenty of solid scientific evidence that we are going through a global climate change and that human activity has contributed to the rate of that change. Obviously that global change will have local effects and may already be producing those effects, Kelly said.