The Climactic Data Center of the National Weather Service has now declared 2006 to be the warmest year on record, based on preliminary temperature data for the entire year. In December, they estimated that the year would go down as the third warmest, but the warm spell during the second half of the month increased the average enough to break the 111 year record.

The national average was 55 degrees, 2.2 degrees above the 20th century average, and a measly 0.07 degrees above the previous record, set in 1998. In fact, using a new methodology for temperature measurement that will go into effect this year, 1998 remains the warmest year.

New Jersey experienced its warmest temperatures ever in 2006, and much of the Northeast, Midwest, and Plains states had top five warmest years. The Southeast and West Coast were also warmer than normal, although not nearly as much as the rest of the country. No state experienced below normal temperatures last year.

So, is this evidence of global warming? The Weather Service hedges the point, saying, “It is unclear how much of the recent anomalous warmth was due to greenhouse-gas-induced warming and how much was due to the El Niño-related circulation pattern. It is known that El Niño is playing a major role in this winter’s short-term warm period.”

On the precipitation side, things were nowhere near as extreme. Only Georgia, Florida, Wyoming, and North Dakota experience much below normal rainfall, while parts of New England and the Midwest had much above normal precipitation. No state set a precipitation record, either dry or wet for the year.

You can read the entire report here.

The scientists over at the Weather Service’s Climate Prediction Center yesterday released a new report showing that the El Nino conditions are intensifying, and that the predicted wet weather with normal to slightly below normal temperatures for much of the Southeast may be delayed, but is on its way.

That prediction may come as a relief to one reader of this blog, who is concerned that we are in a drought situation. While we are way down in the rainfall department this year, I took a look at the monthly rainfall records for the state, which are summarized here. As per usual, rainfall totals have varied widely, but most of North Georgia is suffering from a rainfall deficit this year, primarily from less than normal rain from the March through July period. August brought more than normal rain, while fall saw more or less normal precipitation.

This has been confirmed to some extent by taking a look at the drought outlook and conditions on the Peachtree City NWS site. While we were in a moderate drought over the summer, that condition no longer exists, and the outlook is for improvement, at least over the southern half of Georgia.

The picture above illustrates the typical weather pattern of an El Nino year. In theory, the polar jet stream stays up north in Canada, leaving the middle of the country warmer than normal, while the Pacific jetstream moves across the southern states, bringing wetter than normal weather to much of the West and the Southeast. The CPC’s El Nino report claims that the effects have begun later than normal (but remember, we’re only one week into meteorological winter), but should intensify over the next few months.

The report also predicts that this El Nino won’t be as strong as some of the ones in the past. I’m also concerned that metro Atlanta is on the edge of the area expected to receive higher than normal rainfall. To sum it up, I don’t see where we’re in a drought situation right now, and once this current cold blast ends next week, we’re going to see some rainfall, which should then be normal to above normal throughout the winter.

The Climate Prediction Center issued a press release today, declaring that El Nino conditions have developed in the Pacific Ocean, and there is a possibility that we will have a moderate El Nino through this winter. El Nino conditions occur when sea surface temperatures in the eastern Pacific ocean are warmer than normal.

During years with El Nino patterns, the gulf coast area is typically cooler and wetter than normal, while the northwest is typically warmer and dryer. We most recently had El Nino conditions during the winter of 2002-2003, and prior to that in 1994-1995 and 1997-1998.

The Weather Service is blaming the El Nino conditions for the fewer than predicted number of hurricanes this year. I’m not sure how much it will affect us here in the Atlanta area — we may be too far away from the coast for the pattern to have an effect on our winter weather.

Meanwhile, we got some much needed precipitation today, with almost two inches of rain since last evening. Today’s high temperature of 66 degrees was 17 degrees below normal — the result of cooler air trapped against the Blue Ridge mountains beneath the low pressure system that brought rain from West to East.

The clouds should move out tomorrow, and it looks like we’ll have pleasant weather through the weekend. After that, one model is predicting a cool blast, with lows in the mid 50s for the middle of next week.

This weekend’s weather focal point is in California, where the semi-dormant El Nino is producing torrents or rain in the Los Angeles area. Here are some 24 hour rain amounts in the area, as of 3 PM Pacific Time on February 11th:

Los Angeles Airport - 1.47 inches
Van Nuys - 2.46 inches
Malibu - 1.52 inches
Simi Valley - 1.87 inches
San Diego - .98 inches

The picture below shows the storm centered on Los Angeles:

Meanwhile. on the east coast, the rainy weather on Wednesday moved up the northeast coast, producing snow in some areas of New England. A high pressure system over Texas and a cold air mass from Canada are in control, producing the high wind gusts we saw today and yesterday. Look for the winds to moderate Saturday, and a return to seasonable temperatures, before the rain now in California reaches our area for almost another inch of rain on Sunday.

Although a cold blast of Arctic air is going to affect the North Central states next week, the Southern branch of the jetstream will protect the Atlanta area, and we will see more or less normal February temperatures during the week next week, with the next chance of rain coming the weekend of February 19th.