Hurricane Forecasting Tools: An MRI for the Skies?
There are many fields of study regarding hurricanes. Why some tropical waves form and others don’t, and why some intensify and others don’t is on the mind of many researchers and scientists. In an ongoing study about the genesis process of tropical cyclones, one tool is making strong inroads. The NASA Global Hawk unmanned areal vehicle, also called the Hurricane and Severe Storm Sentinel or HS3 for short, is a cool tool in an age of amazing technology.
Unlike the NOAA WP-3D turboprop, which is a hurricane workhorse often flying through a hurricane’s core at 5,000 to 10,000 feet to sample wind and pressure from what is typically the most intense part of the storm, the HS3 flies well above the cyclone at altitudes from 55,000 to 65,000 feet.
And unlike the NOAA G-IV jet aircraft that samples the atmosphere and steering currents well outside of a hurricane, to help computer models determine unseen currents in the air that could influence a storm’s direction, the HS3 can drop instruments directly on top of the hurricane as well as around it.
And finally, unlike its counterparts, the mission of an HS3 can last for 24 or more hours as the unmanned aircraft departs, flies to, and then crisscrosses above a storm for the better part of a day. Besides the sophisticated microwave sensing equipment used to scan the storm much like a MRI scans a patient, the aircraft itself measures temperature, pressure, wind, and moisture. This represents a data line along the plane’s path. But to find out what’s going on below the 60,000 foot altitude, the HS3 is equipped with expendable sensors called dropsondes.
These small instruments the size of coke cans carry GPS tracking devices and radio transmitters as well as weather sensors to report on a variety of atmospheric conditions from the top of the troposphere all the way to the ocean below. Unlike weather balloons that gather their information and radio it back on ascent, these electronic packages report as they fall to the water, over sparse parts of the ocean, where weather balloons cannot be released.
The information is then plotted and analyzed by the National Hurricane Center as well as gathered by researchers for later study on hurricane behavior. An example of a ?sounding? from a HS3 mission last Friday shows the temperature profile in red, the moisture profile in blue, and the winds at different altitudes on the right as barbs.
Typically the HS3 will drop dozens of sondes in and around the area of interest in either a lawnmower, racetrack, or butterfly pattern. This combination of observations can then be plotted for different levels of the atmosphere. This information is also analyzed and incorporated into the global and hurricane computer models to hopefully improve forecasts.
Stayed tuned, the peak of hurricane season is almost here and things may start getting busy, especially for the HS3 Global Hawk, the NOAA G-IV, and the NOAA WP-3D (as well as Air Force Reserve WC130J) aircraft fleet.
Meteorologist Craig Setzer is the longest on-air degreed meteorologist at CBS4 and myTV33 news. His experience in the #1 hurricane market in the country makes him uniquely qualified to cover them and inform you. Few meteorologists in the South Florida market have the education and experience to cover hurricanes and severe weather like Craig does.
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