Difference of Degrees Has National Weather Service Sweating

The discrepancy has the authority on those numbers -- The National Weather Service -- sweating over some recent inconsistent readings.

On various days over the past few months, the official temperature sensor atRaleigh-Durham Internationalhas widely varied from the reading at theNational Weather Serviceoffice in Raleigh.

On July 4, the airport gauge showed it was 99 degrees, five degrees warmer than the National Weather Service reading. On July 7, there was again a five degree difference, and July 18, it was four degrees higher at the airport.

"When you're in the weather business, its frustrating because you're deciding if you're going to forecast for reality, or what that sensor is going to end up showing on that particular day," saysWRAL Meteorologist Greg Fishel.

Since May, Weather Service technicians have checked over the airport's system three different times.

"We feel very comfortable that the system is working and is registering the temperature where it's located," says Steve Harned, the Meteorologist-in-Charge at the National Weather Service.

Harned says they have found no explanation for the inconsistencies, so far. However, he points out, some days the airport reports cooler temperatures, and other days, like the record-breaking July 5, the sensors were right on.

Speculations about what's causing the discrepancies abound. The government placed the monitoring instrumentation next to a runway three and a half years ago to give aircraft the most accurate weather readings.

Some wonder if heat radiated from the runway or even nearby construction projects somehow influences the thermometer when winds blow from the south. For now, it is a meteorological mystery.

"We need to make sure that all of our instrumentation, not only here, but across the country and the world, is truly representative of the climate," Fishel said. "And if it's only representative of a strange thing at the airport, then we need to do something about it."

The Weather Service has launched a study to get to the bottom of the unusual readings, tracking weather statistics for the past three and a half years.

Officials are looking for trends at weather stations around the area by comparing temperature, wind speed and direction, and even cloud cover. It should take about two months to complete the study. Reporter: Cullen Browder