Third runway may affect Sea-Tac weather readings


by KING 5 News

Posted on August 1, 2013 at 5:02 PM

Updated Thursday, Aug 1 at 5:38 PM

The weather station at Sea-Tac International Airport may be the most important station in Western Washington.

It's possible a new runway at the airport is affecting weather readings.

The station has been recording weather at Sea-Tac since 1945. It tells pilots information like wind speed and direction, and visibility.

For the first July in over 50 years, not a single drop of rain fell at the airport.

"I've noticed it in the last couple three months, and I will look at it during our great weather and it will be warmer than any of our other official stations by one or two degree," KING 5 Meteorologist Rich Marriott said.

The construction of a third runway -- a giant slab of temperature-holding thick concrete -- may be affecting the weather station's readings.

University of Washington atmospheric scientist Cliff Mass said Sea-Tac's station may be saying less about our weather as a whole than it used to.

"I mean what can you say? The environment has changed radically around the airport," said Mass.

Decades ago only a few stations kept track of real-time weather. Today there are thousands, which makes KING 5's Futurecast possible.

But for official records, Sea-Tac keeps the official records.

The Sea-Tac Airport said the third runway has done one thing: boost the airport's on-time record to be one of the best in the country.