Where weather begins

  • Published
  • By Capt. Uriah Orland
  • Alaskan Command Public Affairs
EARECKSON AIR STATION, Alaska --  Exiting the plane one immediately realizes the importance of weather at Eareckson Air Station on Shemya Island.

This day there was a 40 mph crosswind, driving a steady sheet of ice cold rain and sleet. The island was in Phase II weather which means winds 50 to 70 mph and travel is restricted to the work area. The forecast was to remain in Phase II for another four hours.

But how do personnel on an island 1,500 miles from Anchorage get a weather forecast? The lack of weather stations in Eastern Russia or the North Pacific to pull data from requires them, in a way, to make it up.

"We are in a data sparse environment on Shemya," said John Semanick, an information coordination center technician with Chugach McKinley Inc., the island's base operating support contractor. "To help fill that void we gather data from as many sources as possible. That includes our observations, pilot reports and weather balloons we launch."

Weather balloons are launched around the world at the same time of the day - noon and midnight Greenwich Mean Time. At Eareckson AS, that's 2 a.m. and 2 p.m.

"The balloons collect the temperature, winds aloft, pressure based on altitude and the dew point," said Mr. Semanick. "This data is compiled with surface data and pilot reports to initialize weather models or forecasts."

Although the balloons are launched from Eareckson AS, the weather forecasts are made 2,800 miles southwest by the 17th Operational Weather Squadron at Hickam Air Force Base, Hawaii.

The data is also used by meteorologists around the world to create upper air weather charts, predict severe weather based on the energy in the atmosphere, and predict precipitation, icing conditions, turbulence and jet streams.

"The nearest balloon launches to us are in Japan, Cold Bay and Hawaii. Because we are so data sparse we send as much information to the 17th Operational Weather Squadron as possible," Mr. Semanick explained. "We also send them regular weather observations to correct their models if necessary."

It is essential to flying operations at Shemya to have good weather forecasts as well.
"The closest alternate runway is 392 miles away at Adak and the next is 900 miles away at Cold Bay," said Ron Nelson, a captain with Flight Works, who flies the regular rotator to the island.

The weather can be so severe at the island that the Air Force has special requirements written into the contract.

"This is one of the few spots where the Department of Defense requires the pilots to have a certain amount of Alaskan flying hours. It takes an experienced pilot to land with 40-50 knot cross winds," said Captain Nelson.

The severe weather over Shemya is a result of warm air circulating north and east from Japan colliding with cold, arctic air flowing south. This mixing of warm and cold air can change the weather at a moment's notice.

"One flight we were coming in on final approach and the skies were partly cloudy with good visibility," said First Officer Russ Polsky with Flight Works. "Within five minutes there was a 30-knot cross wind with blowing snow."

This drastic weather change is not uncommon and is the reason they say on Shemya, "If you don't like the weather, wait a few minutes and it will change."