2007 likely sets heat record for the hemisphere

The Northern Hemisphere is on track for this year to be the warmest since record-keeping started 127 years ago — not too surprising for Utahns, who have also sweltered under record heat, at least for a portion of the year.

Hemispherewide, temperatures for January through October averaged 1.3 degrees above the norm and could break the record for the warmest year set in 2003, according to the National Climatic Data Center. The warming trend could impact the melting of Arctic sea ice and worsen drought conditions throughout the United States.

In Salt Lake City, the summer of 2007 was the warmest ever on record. The months of June, July and August averaged 0.7 degrees warmer than they did in 1994 — the previous record-breaking year. July was Salt Lake City's hottest-ever record; August was its second-hottest.

In addition, spring 2007 in Salt Lake City was the third-warmest ever recorded, according to the National Weather Service office in Salt Lake City.

In the United States, the period from January to October was the seventh warmest since records began in 1895, according to the national data center.

As for the coming winter, the recently updated U.S. forecast by the Climate Prediction Center calls for unusual warmth to persist across most of the nation — 4 percent warmer than the 30-year average — continuing a decadelong trend of warm winters.

Michael Halpert, deputy director of the Climate Prediction Center, cautions that no link can be made between this string of mild winters and manmade climate change.

In medium-elevation states like Utah, it's too early in the year to predict whether this winter will be abnormally warm, according to weather service lead Salt Lake City forecaster Mike Seaman. It is equally likely, based on available data, that Utah will see an abnormally cold season as an abnormally warm one.

As for rain, "La Nina strengthened during October, making it even more likely that the USA will see below-average precipitation in the already drought-stricken regions of the Southwest and the Southeast this winter," Halpert said.

Besides the Southeast, where 76 percent of the region is in some stage of drought, dry conditions also plague the West, where 57 percent of the region is in drought.

Utah is off to a late start in terms of precipitation, according to Seaman. However, northern Utah may see more precipitation than average by spring.

Conversely, southern Utah is expected to experience less precipitation than normal. Both areas are expected to remain in either "severe" or "moderate" drought conditions, with parts of the extreme southeast expected to remain in "abnormally dry" conditions, according to the climate prediction center.