Hunting Hugo: Take-off

By Jeffrey Masters, Ph.D. — Director of Meteorology, Weather Underground, Inc.

At last, take off. The familiar roar of the engines shake the aircraft as the thrust of take off pushes me back into my seat. The lush greenery of Barbados rushes past, then falls away as the big plane lumbers into the air. We cross the coast, the spectacular turquoise-blue waters of the Caribbean sparkling up at us in the intense tropical sunshine. The tranquillity and beauty of the scene make it difficult to believe a huge, destructive hurricane lurks a mere hour's flight away.

We climb to 10,000 feet and level off, heading northeast. I check the lower fuselage radar display. The bright reds and yellows of Hugo's outermost spiral rain bands have already appeared. It is a huge storm, over 400 miles in diameter.

"Look at that radar presentation!" I exclaim over the intercom.

"Yeah, that's a pretty good looking storm," replies Frank Marks, lead scientist. "Looks like it has its act together."

"Hey Jeff, what kind of track do you want?" interrupts Gerry, from the cockpit.

"Let's go with a track of oh-seven-oh until we start getting near the outer spiral band," I reply.

"Turning to oh-seven-oh!" says Gerry.

Gerry banks the airplane to bring us to a heading of oh-seven-oh degrees, and levels us out. I begin studying the lower fuselage radar display to gauge Hugo's intensity and position in more detail. Suddenly, a blank screen meets my gaze.

"We just lost the radar system," I hear electronic engineer Al Goldstein say over the intercom, before I have a chance to report the problem. "Terry's got the circuit boards pulled, and we're checking things out."

This is not good. Loss of the radar slung under the lower fuselage and the Doppler radar located in the tail severely limits our ability to estimate the strength of the hurricane and determine a safe altitude to fly at. Moreover, the radar data is critical to the experiment we are conducting. The science team may want to delay the mission while repairs happen. I unbuckle my seat belt and walk to the rear of the aircraft, where the scientists are already discussing the problem.

"Frank, do you want to orbit here while Al and Terry work on the radar?" I yell over the noise of the engines, when I arrive.

"No, let's hold this heading and see if they can get it fixed while we ferry to the storm," Frank replies. "Terry and Alan can do some pretty amazing repair jobs--I'm betting they can get it fixed soon. We'll re-evaluate in about 20 minutes."

Nodding, I head back up front, take my seat, and inform the crew of the plan. I think it is a wise one--Terry and Alan are the best in the business. Odds are, they will get things fixed in time to perform the entire mission as planned. We drone on towards the now-invisible storm.

As the next 20 minutes pass, I check my data displays, snap a few photographs out my window of the distant storm clouds, and wait restlessly for radar display to reappear. It is an uncomfortable feeling, flying blind towards a huge hurricane of unknown intensity. We are the first hurricane hunter airplane to intercept the storm, so we have only satellite estimates of how strong the hurricane is--and satellite estimates are notoriously unreliable. This is why the National Hurricane Center relies heavily on the information provided by hurricane hunter aircraft to issue accurate hurricane forecasts and warnings. An Air Force airplane is scheduled to fly a reconnaissance mission today, but we will beat it there.

Finally, just five minutes from our planned descent point and only fifteen minutes from Hugo's first spiral band, the radar display flickers back on.

"It's back--for now," Alan tersely informs us.

"Great work, Alan and Terry!" responds Frank Marks.

Immediately, I lean in close to my screen and study the newly restored radar display. Hugo has an impressive symmetry, with two major spiral bands and a 12-mile diameter eye--pretty tight by hurricane standards, and difficult to orbit inside should we get in trouble and need to stay in the eye. I've been in several other hurricanes with eyes this small, and both were rough, intense storms undergoing rapid deepening. Hugo may be doing the same. I look closely at the eyewall--a tight ring of bright orange and red echoes surrounding the eye. Checking the echo intensity scale at the side of the display, I find that the radar information looks consistent with this morning's satellite estimates of Hugo's intensity--winds of 130 mph and a central pressure of 950 millibars, a strong category three storm on a scale of one to five.

My examination of the radar display is fairly hurried, and I fail to notice that the strongest echos from the radar display are off scale. Typically, one of us takes the time during the ferry to a hurricane to properly scale the radar reflectivities, but no one has done so this time, because of radar system's failure during approach.

Frank appears at my station, and I remove my headset to talk.

"Looks like an impressive storm!" He shouts above the noise of the four engines. "We need to do the mission at an altitude that's low, but no so low that its real rough and we get bad radar data."

"Well, Hugo's definitely getting his act together," I shout back. "Do you still want to try it at 1,500 feet?"

"Well, we got away with it in Hurricane Gabrielle last week, and Hugo looks like it's about the same strength. Let's try the first penetration at 1,500, and if it's too rough, we'll climb to 5,000," he answers.

"OK, 1,500 it is!" I yell back. As Frank disappears back into the cockpit to take the chief scientist's seat, I get on the intercom.

"Lowell, they want to go in at 1,500 feet. How do you feel about that?" I sound and feel nervous about this choice.

"Fifteen hundred, hey?" he responds. I can tell by his tone of voice he feels none too comfortable with this choice, either. "I'd be happier at 5,000."

"Yeah, me too. But we got away with it last week in Gabrielle, and if it's rough on the first penetration, we can do the rest of the mission at 5,000."

"All right," sighs Lowell. "We'll take her down to 1,500 and see how it goes. Are you happy with this track?"

"Looks OK for now, we may want to adjust a bit when we get down to 1,500. Standby, we're almost at our descent point."

I wait a minute until we arrive at our planned descent point, then give the command, "OK, let's descend to 1,500 feet at 1,000 feet per minute."

"All right, here we go!" replies Lowell.

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