Breeze a factor for base

  • Published
  • By Nick DeCicco
  • 60th Air Mobility Wing Public Affairs
TRAVIS AIR FORCE BASE, Calif. --  Recent weather has been confusing, with rain and thunderstorms April 29 conflicting with high temperatures reaching 80 just a few days later.

As the calendar crawls forward and spring turns into summer, the rise in temperatures comes with a phenomenon highly familiar to those in the weather flight at Travis -- the delta breeze.

The breeze is caused by a gap in the mountains of California's Central Valley. Cool air pushes through the San Francisco Bay and into the gap, funneling winds directly toward the base.

"It's a very localized phenomenon," says Master Sgt. Rob Lenahan, weather flight chief for the 60th Operations Support Squadron.

The breeze is but one regional weather factor for which members of the 60th OSS's weather flight keep a watchful eye. The flight monitors local as well as regional, national and international conditions due to the wide scope of Travis' mission.

Each base's weather mission comes with its own conditions and mission requirements, said Sergeant Lenahan, whose 11 years in weather have taken him to five different duty assignments. Each location comes with varying local factors such as geography, terrain and topography which help shape and manipulate the conditions.

"Each aircraft has different specifications and limitations, too," he said. "One may not be able to take off in 30-knot crosswinds."

Travis' three airframes have different needs when it comes to weather information, too, said Master Sgt. John McDaniel, the weather flight's noncommissioned officer in charge of operations and training. The C-17 Globemaster III is more concerned with low-level conditions whereas C-5 Galaxies are primarily concerned with conditions 20,000 feet and up, he said.

However, the delta breeze is a subtle phenomenon with its energy focused primarily on Travis' particular location. It's not uncommon to see a 10-degree difference between the base and Nut Tree Airport in nearby Vacaville, Calif., said Sergeant Lenahan.

"The favorable winds coming in from the delta breeze make Travis a unique location," said John Lacomia, the historian in the 60th Air Mobility Wing History Office.

As Staff Sgt. Ryan James, a technician in the weather flight points out, while the breeze is the feature in the summertime, from December to March, heavy fog conditions can ground all activity on the flightline.

"When there's fog and nobody can take off, everyone stands here at our counter," Sergeant James said.

Travis members, with the help of the Automated Meteorological System -- a collection of sensors placed throughout the airfield --observe and report on the weather. Airmen at Davis-Monthan Air Force Base near Tucson, Ariz., write the forecast for several bases in the Western United States including Travis.

Travis' conditions take some getting used to, as Senior Airman Jared Powell, a weather forecaster in the flight, can attest.

Airman Powell has been at Travis only a brief time and is still mastering the skies, learning which clues suggest what may develop. Because of the ocean and winds,

Travis provides a challenge different from, say, assessing the likelihood of tornados on the plains.

"It's like learning how to use new tools," Airman Powell said.
Sergeant James agreed.

"You have to re-learn the way the winds work," he said. "North winds in summertime mean a heat wave, but southwest winds bring the cold off the ocean. It's just so backward."

The varying conditions from one locale to the next are a part of what Sergeant Lenahan loves about the career field.

"Every place is different," he said. "That's one of the things I like. There's always a new challenge."

To hear current weather conditions at Travis, call 424-6592. To convert temperatures from Celsius to Fahrenheit or wind speed from knots to mph, visit http://www.albireo.ch/temperatureconverter and http://www.srh.noaa.gov/epz/?n=wxcalc_windconvert, respectively.