About one-fourth of our local news broadcasts are devoted to weather, it seems. And admit it, here in Southcentral Alaska we identify our chief weather celebrity by her first name: “Jackie.” After all, she is a local, and we Alaskans do favor the “hometown girl.”
But every day, behind the scenes, scores of weather experts across the state employ supercomputers and an array of equipment to bring us daily forecasts and predictions that reach out at least seven days.
Because I venture outdoors often, I’ve come to rely on National Weather Service (NWS) forecasts. And in my wanderings over the years, I’ve actually found instruments that are a key part of weather forecasting. They’re called Radiosonde units. Each day two of them are affixed to balloons and launched skyward by NWS meteorologists at the Anchorage Forecast Office.
Across Alaska, 13 are launched each day.
“The units ascend to a height of about 100,000 feet in about 90 minutes and their instrument packages transmit data to the ground on air pressure, temperature, wind speed (in different layers of air) and wind direction,” Louise Fode, NWS warning coordination meteorologist, explained.
With thinning air at high altitudes, the hydrogen-filled, latex balloon expands to the point that it bursts, and the unit slowly falls to the ground by parachute. The three that I have found during a 25-year period were in a roughly 20-square-mile area in the Eklutna drainage.
NWS reports that only about three percent of the units are ever recovered – meaning that my discoveries are well above the average for all units as well as for one single discoverer.
Data from the Radiosondes, along with information from ground stations, satellites, airplanes, ships, and buoys, is fed into supercomputers capable of crunching trillions of operations every second. These analyses and models provide meteorologists with a big picture of what the atmosphere has in store. It gives them the first glimpse of tomorrow’s weather – a glimpse that allows them to provide – as the NWS likes to say, “watches, warnings, and advisories for protection of life and property and enhancement of the economy.”
“Anchorage’s proximity to the Gulf of Alaska and mountainous terrain poses some challenges to Anchorage-area weather forecasting,” Fode said. “Wind travels up and down the mountains like waves of water, causing dynamic, ever-changing conditions.”
Mountain ridges block radar signals, she adds. On one side of a mountain, a gentle breeze may blow. But on the other side, that gentle breeze may be funneled into a gale.
“Siting (positioning) instrumentation in Alaska’s extremely rugged terrain can also pose some great challenges,” she notes.
Fode says that improvements in radar, satellite and radar imagery, as well as computer modeling, have significantly improved forecasting. In addition, Alaska now has about 150 or 200 observation points showing temperature and wind speed from locations scattered around the state.
Having closely watched the weather for more than 50 years, I contend that forecasts have improved. They aren’t always perfect, but they’re vastly improved over what they were just 10 years ago.
Some might say we Alaskans are outrageously obsessed with climate and weather. But since we live in an area with such a dramatic weather shifts, especially during winter, it doesn’t seem unreasonable. One day a lightweight coat seems fine. But on the next, a down parka might be needed. Or these days of “climate change,” we might need a raincoat in the middle of winter.
Perhaps some of our fascination with weather is that we want to compare ours with other places, perchance to make ourselves feel better.
“Wow, those poor folks at Northway have -50 degrees,” we’ll announce in front of the television. “Sure glad I’m not up there now.”
Old-school cynics like my late father and brother-in-law would say: “If you want to know the weather, stick your head out of the door.”
Having met some of Anchorage’s NWS weather scientists and learning about the procedures and tools they use, I now have a much deeper appreciation for the amount of detail and work that goes into forecasting.
My arthritic knee tells me a little about changing weather, but if I plan to venture into the mountains or backcountry the next day, I’ll invariably put my faith in the NWS.