Sunday, January 27, 2013

Using tech to better understand Hawaiian weather

It wasn’t all that long ago that we didn’t know a hurricane was headed our way unless a ship had sailed through it and radioed a warning.

Satellite technology—allowing us to see tropical storms develop from infancy to powerful systems with distinct eyes—has changed all that.

But a satellite—the ability to see water vapor and heat signatures from a distance—doesn’t tell us everything we need to know. That’s why pilots and crews put themselves at risk to fly into the heart of cyclones to gather data.

The June-to-November hurricane season is of concern, but in winter, the Islands  face different weather systems that also have the ability to cause massive damage—like fronts that bring intense downpours, sweeping flash floods down narrow valleys. They can close roads, wash away homes and cars, and flood vast lowlands.

Kaua`i knows that more than most. Falling trees and rocks regularly close roads during rainstorms, and residents of the North Shore know too well the problems of a highway under feet of muddy water.

We still need understand some of these weather systems better.

As this story is published, the National Oceanic and Atmospheric Administration, is sending one of its hurricane-hunter aircraft on regular flights into the North Pacific to better understand the genesis of severe weather patterns over the ocean. It is a mission that has been underway winters since 1999.

A specialized NOAA jet, a twin-engine Gulfstream IV-SP, is flying into the North Pacific out of Hickam Air Force Base through Feb. 27 and then from Anchorage, Alaska, through March 10.

On each of multiple trips, the plane will release multiple recording devices called dropsondes.
Each device will fall for 17 minutes before broadcasting the data it has collected. That data will include recordings of pressure, temperature and humidity four times per second, and the GPS location and wind speed and direction twice per second.

The direction of the flights will be dictated by the National Centers for Environmental Prediction, a branch of the National Weather Service.

The recorded data will be immediately available to weather forecasters in the Islands, said Jack R. Parrish, flight director and meteorologist with NOAA’s Office of Marine and Aviation Operations.
The data is valuable in part because it establishes a three-dimensional view of the weather, rather than a satellite image, which only looks down from on high.

 “These additional targeted observations, combined with data from other observing systems, enhance the accuracy of the forecasts, especially for high impact winter weather events. By improving our forecasts, we can alert the public, emergency managers, air carriers, utility companies and others sooner so they can prepare more effectively for significant storms, and save lives, property and money,” said NCEP Chief Science Officer Barry Choy.

Whether a ship at sea or a dropsonde falling from a jet, the best weather data still comes from folks actually traveling in the storm.

DROP-IN: If you want to follow what’s happening in the weather on social media, see

© Jan TenBruggencate 2013

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