James A. Eberwine
After twenty-six years of talking about, studying, and teaching hurricane preparedness I had an opportunity to fly onboard November Four-Three Romeo Foxtrot (N43RF), one of the WP-3D aircraft operated by NOAA's Aircraft Operations Center(AOC) at McDill AFB Tampa, Florida. I was beginning to think that such an experience would elude me for the remainder of my career, even though I had inquired about the opportunity more than nine years ago. My interests in hurricanes were actually stimulated in 1976 when I had the occasion to fly with Dr. Neil Frank, then director of the National Hurricane Center (NHC), as he took pictures of the New Jersey and Delaware coastlines while remarking about the build up taking place. The reason it took so long was a matter of priorities. One of the stipulations was that we could not fly into storms that were going to threaten any part of the eastern seaboard, especially our own County Warning Area (CWA). My position at the National Weather Service Forecast Office Mt. Holly, New Jersey is that of an operational forecaster. However, I am also the Hurricane and Marine program leader. Another consideration was space availability and the extent of the airborne research planned.
As each new hurricane season rolled around, and a tropical storm formed in the Atlantic Basin, the cries from my colleagues were, "Jim, this could be IT!" After listening to the hurricane forecasters at NHC/TPC discussing this dangerous late season hurricane, after plotting Mitchs' position on our six by four-foot magnetic plotting board, after broadcasting the latest bulletins all night over the NOAA weather radio, and returning home following my fourth midnight shift, the call finally came. At 930 a.m. October 26. "IT" was soon to become a reality!
The remainder of the day was simply a blur. I scurried about making airline reservations to Tampa, Florida. The next two days were my scheduled days off. There was a meeting in Sussex County, Delaware that I was supposed to address, but that was handled by my co-workers. I had to inform my Meteorologist-in-Charge, and the staff what I was planning to do. And, I had to track down my wife and tell her. I departed my home in Absecon, New Jersey(near Atlantic City) without having had any sleep and drove to the Philadelphia International Airport for an 835 p.m. departure to Tampa with a connecting flight in Atlanta, Georgia. I arrived at my hotel at 130 a.m. Tuesday, October 27. The sleepless day and the hectic schedule were a very small price to pay for what I was about to do. At this point, I did not have any second thoughts about flying into the hurricane. My only fear was oversleeping and missing the flight so I not only set my alarm, but placed a wake-up call at the front desk.
While walking to the coffee shop I exchanged greetings with Professor Stan Gedzelman, a university scientist from the City College of New York (CCNY) who would also be flying into Mitch. We spoke for a while then departed, but would later meet at 11:00 a.m. in the lobby for our ride to McDill AFB. Shortly after 11:00 a.m. John Gamache, a lead project scientist, and Rob Rogers a post doctoral student, from the Hurricane Research Division (HRD), met us and we left for the Air Force base. Our ETD was 130 p.m. As we drove on, I couldn't help but notice that it was a beautiful "fall" day in Tampa with peaceful sunny skies and a temperature of 80 degrees. The last time I checked on Hurricane Mitch he was a CAT-V. I then thought to myself what a difference a few hundred miles are going to make.
We arrived at McDill AFB around 1130 a.m. and were escorted into the Aircraft Operations Centers' hangar which housed several aircraft including the latest research platform, the sleek looking Gulfstream IV-SP high altitude jet (G-IV). As I reached the second floor of the hanger bay area, I glanced at the white fuselage gleaming in the noontime sun sitting on the tarmac. It was N43RF, my chariot into Hurricane Mitch. By 1245 p.m., room 205 was abuzz as the project scientists were handing out, and discussing the assignments. Mission 981027I1 was going to conduct a modified "Eyewall Vertical Motion Structure Experiments" (EVMSE) in Hurricane Mitch. This experiment was part of the "1998 Hurricane Field Program Plan," a progression of experiments that are conducted throughout the hurricane season. Knowing that previous analysis "confirmed the results of the flight level study in that the EYEWALL contained the strongest and largest updrafts," this was going to be a very interesting flight to say the least. I spent the last few minutes chatting with several people and going over the latest bulletins from the National Hurricane Center which indicated that there was some weakening, but not much. I also learned that the GOES-8 pictures had been interrupted and NHC was relying on a GOES-10 fix. This reminded me of what Dr. Robert Sheets, former director of the NHC once said, "satellite photos and other measurements can't replace aircraft data." It seemed as though there was a greater urgency to get N43RF into the storm. There was also some paperwork to finish. We were given a handout "Crewmember/Passenger Guidelines and Information" and asked to read it, fill out the pertinent information, sign and date. The bottom of the page read, "Welcome Aboard!"
The NOAA WP-3D aircraft, its crew members and scientist, as well as the 53rd Weather Reconnaissance Squadron of the Air Force Reserve. (AFRES) are highly respected in the meteorological community. Wherever I go to speak on the subject of hurricanes, I am always asked to discuss "The Hurricane Hunters." Prior to my flight into Hurricane Mitch the information was generally second hand, although I have been through the aircraft during their off season city tours, and have attended conferences and workshops with project scientists from the WP-3D. In case there is anyone reading this and not familiar with hurricane research you can peruse the home page of Atlantic Oceanographic and Meteorological Laboratory (AOML) for an excellent summary of tropical storm research. I will say that the WP-3D is a flying laboratory and the worlds most heavily instrumented research aircraft. The four engine turboprop was commissioned in the late 70's and is well suited for safe flight operations into convection and turbulence. The United States is the only country that makes routine flights into hurricanes. The planes' most striking features are its nose probe, the five-cm wavelength Plan Position Indicator (PPI) radar in the radome below the fuselage, and the three-cm wavelength Range Height Indicator (RHI) radar in the tail radome.
As I walked out to the tail of the aircraft, I noticed the red hurricane decals on the port side of the fuselage indicating what storm's N43RF had flown into. The first was Anita in 1977 and there have been many since then. There were two hurricanes with the caption "cat 5" over their names, Allen in 1980 and Gilbert in 1988. At that point I realized that I was about to fly in an airplane, which in its own right, had achieved "celebrity" status. As I started up the stairs of the aircraft, someone yelled to me, "are you really going on this flight?", I turned and responded as if a celebrity myself, "Yes!"
We were getting very close to our departure time of 130 p.m., but first, there were some very important safety issues to go over. Condition 1 in Appendix E of the NOAA Research Operational Procedures and Check Lists states, "Turbulence/Penetration. All personnel will stow loose equipment and fasten safety belts." The very first directive we were given by one of the pilots was pay particular attention to the "fasten seat belt" sign especially when it is illuminated, but that we could walk around when it wasn't lit. There was also a bell and an announcement that it was time to buckle-up. He showed us how to get into our three-point shoulder and lap harness. We were also instructed how to properly put on the life vest in the event the aircraft had to ditch. Ditching is when the plane is forced to land in the water because of mechanical or other problems. I refused to even think that this would be a viable option especially when the seas under the hurricane were heaped up and rough, and the winds 150 miles an hour or more. Nonetheless, safety is primary on any aircraft especially one that flies into some of the worst weather imaginable. Finally, we were shown the exit doors and the quickest and safest way to get to them. It was time to taxi!
As I mentioned above, the skies were sunny and peaceful over Tampa and the visibility excellent as the aircraft rotated upward on a heading toward the south southwest, or down the Gulf Coast of Florida. You could see for nearly 70 miles in all directions. Fair weather cumulus dotted the interior sections of Florida but vanished the farther out into the gulf we flew. The four engines roared as N43RF climbed at 1000 feet per minute on our outbound leg in search of its' assigned altitude of 23,000 feet. The seat belt sign went out and you could hear metal striking the floor of the aircraft as we freed ourselves from the harnesses. This was a maneuver that I would repeat many, many times during the flight. Once free I was able to walk throughout the aircraft. The forward area was made up of a series of workstations with an isle between them about the same width that you would find in an MD-80 commercial aircraft. The primary positions at the workstations consisted of the Lead Project, Cloud Physics, Radar/Doppler, Dropsonde, Workstation, and C-band scatterometer/Stepped-Frequency Microwave Radiometer Scientists. The navigator sits aft and starboard of the cockpit.
The middle section had three jump seats and one work station. The workstation was where the scientist launching the dropsondes would sit. There was plenty of room to walk around in this area. The restroom and galley were in the rear of the aircraft with an overhead bunk on top of the dining table. There was plenty of soda, hot coffee and sandwiches. The coffee would prove to be a welcomed beverage at a later time. By this time I had already walked almost the entire length of the WP-3D which is 111 ft 2 in.
As we approached the Yucatan Channel, I noticed the sky and sea state undergoing change. I was told that we were under the Central Dense Overcast (CDO), that part of the cirrus outflow that looks similar to the teeth of a buzz saw. At the lower levels I could see the swirling motion of the cumulus clouds arcing in the horizon. This is the extreme outer edge of the storm. Smooth sea conditions were changing to whitecaps, and the frequency between the waves was reduced with each passing mile. I glanced at the Doppler radar and saw a "hard" target off the left wing tip. A hard target, or one that exhibits zero velocity on the Doppler velocity scale, is referred to as anomalous propagation. I quickly aligned myself with the radar image and determined that we were just west of the island of Cuba. This was fascinating in itself to be so close to a country that was both mysterious as well as intriguing growing up. Still free to roam about, I occasionally checked our position. There was a Distance Measuring Equipment (DME) readout which showed exactly where N43RF was at all times in relation to our IP, or Initial Position. The IP was the center of Mitch. By this time I had conversations with nearly half of the people on board, and was gathering a wealth of knowledge about the aircraft and our "routine" for the next several hours. The workstation, aside from being a composite readout of our position, with the push of a button became a Doppler radar workstation, and also our eyes as the video cameras on the nose and wing tip documented our every move. November Four-Three Romeo Foxtrot was on target!
I was very comfortable with most aspects of my surroundings. I hold a private pilots license, have worked weather surveillance radar since 1977, the Doppler since 1993, have taken fingerprints of the atmosphere and ocean utilizing weather balloons and XBTs, have been on board other research aircraft at the FAA Technical Center in Pomona, New Jersey, and as mentioned above, have preached Hurricanes for many years. I also knew that I was entering a new frontier, but one that I had trained for many, many years.
The tuna sandwiches I brought were in the refrigerator. Do I eat them now or wait a little longer? I wasn't sure if I should take time out to eat, for fear of missing anything, or was it because of other reasons. Anyway, I opted for a cup of coffee. Before penetrating a tropical storm the aircraft engineers perform a once-over of the aircraft. I was sitting down drinking my coffee when one of the engineers walked toward me with a screw driver in his hand. He bent down next to my seat and with a couple of turns managed to pull up one of the floor panels. I held onto the armrest and glanced straight down and saw more of the white caps and low clouds. He reached down into the well and attached a camera to a track. The belly-cam was ready. Needless to say, I made sure that I inspected my every step each time I left my seat! After tossing the coffee cup into the trash bin I turned to walk toward the cockpit. At that point I heard the tone, saw the red "seat belt" sign come on and heard the pilot say, "It's time to buckle up."
I was glad I held off on the sandwich. The pace to get back to my seat was rather a casual stroll, but no sooner did I fasten the harness then we were into the first "shock waves" emanating from the hurricane at ten thousand feet. I glanced down the center aisle toward the cockpit and did not see a soul walking around. The scientists were glued to their workstations, and the navigator steadfastly plotting our course. I had company next to me on my right, and across the aisle from me. Paul, to my right was ,matter of factly, describing our encounter and other hurricanes he had flown into. Jack, across the way, was busy recording the flight with the digital camera, but still managed to take a bite of his sandwich. The anticipation was mounting. The aircraft was jolted several times, but then, the turbulence subsided. I heard the pilot give the seat belts off command as he proudly proclaimed, "We are entering the eye!"
I couldn't get the harness off quick enough. What surprised me was how excited everyone in the aircraft got, but they allowed me the first glimpse at the eye and shared their window seat. This is the image that remains with you forever! The air was very still and there were low clouds within the eyewall. I looked straight up and could see the break's overhead and the curving motion of the clouds and peered down through the cumulus clouds to the rough sea . I tried from every vantage point to see the eye. I walked to the cockpit stopping along the way to talk with several scientists while gaping out every porthole that I could find. It was everything imaginable. I was looking at Mitch with my own eyes and through the eyes of the three and five centimeter radars mounted on the belly and the tail. There was some disappointment expressed because the picturesque "stadium effect" was gone from yesterday when the central pressure dropped 58 millibars(MB) in twenty-four hours.(Mitch) Still a strong CAT IV with very strong boundary layer winds of 160-170 kts(185-197 mph), the storm would undergo a pressure rise of 59MB in a period less than twenty-four hours.(Summary) Hurricane Mitch, once a gigantic atmospheric sinkhole, was now exhaling at a rapid pace!
For the next several hours, we repeated 50 nm radius legs into one side of the hurricane then out the other side dropping the GPS (global positioning sondes) into the eyewall to determine the strength of the storm and measure the intense up and down drafts. It wasn't long before I realized that, even though I was not at one of the workstations, I could tell exactly when it was going to get very rough. I continued to keep one eye on the seat belt sign, but then once belted in, I listened for the "swoosh" sound made by the GPS tube as the scientist opened the top of the tube and prepared for another release. Shortly after release, we were into the turbulence. With each pass through the eye, we worked our way up the turbulence scale from light chop, to moderate and severe. Extreme turbulence, the absolute worst type, is when everything in the cabin is thrown about and the aircraft uncontrolable at times. Since everything in the aircraft was either bolted, clamped, taped, locked or strapped in, there weren't any flying objects, although we were pulling two and a half g's, or two and a half times our body weight. And, as we approached the eyewall the sound of the engines was drowned out by the wind driven rain sweeping across the fuselage as if we were in a car wash with fire hoses at each side. There were handrails throughout the aircraft with one running the length of the plane on the overhead bulkhead for those brave souls who dared venture about when the seat belt sign was on. I knew better at this point. I attended parochial school most of my life and when told to "get in my seat" I did just that. This was no different. At one point we hit a pocket of turbulence and everything shook violently. The different noises sounded like a well tuned brass band marching down main street U.S.A. in a parade. I even grabbed the track under my seat, for what reason I don't know.
Hurricane track forecasts have improved, albeit slightly, over the last several decades. The hurricane's intensity, however, remains a mystery. What is known is that hurricanes continue to intensify over warmer waters. The sea surface temperature over the western Caribbean Sea, on October 26, was thirty degrees Celsius. On the other hand, hurricanes begin to weaken once they move away from their warm source and the circulation begins to interact with the nearby terrain. Hurricane Mitch had enjoyed the riches of the Caribbean Sea and deepened to 905 MB, but was becoming trapped along the coast of Honduras and starting to feel the effects. We had been on station for hours. The tropics are typically humid, but when in the center of a hurricane the environment is comparable to a sauna. Fresh air was gushing into the cabin, but after removing the high humidity from it. The drier air was much cooler and it felt like a refrigerator in the rear of the aircraft. The heat from the workstations created a more comfortable environment in the front section of the plane. Once we were in calm air again, I put my long sleeve shirt and hat on, then set out for another cup of coffee. After my fourth cup of "hot" coffee, I didn't bother stirring in the cream and sugar for Mitch was doing that.
As the last minutes of daylight faded, I began to conduct my own research. After reading a report from HRD, I was aware that CG lightning is relatively scarce in the eyewall region of a tropical storm. In fact, Mike Black, an HRD scientist on this flight coauthored papers on the subject. Tropical Cyclone Electrification Studies, and Cloud to Ground Lightning and Tropical Cyclones. I saw what appeared to be lightning, but it was only the strobe light from the airplane ricocheting off the clouds. This was later confirmed after talking to the crew. My second observation was whether tropical systems display strong reflectivity fields, i.e., DBZ returns(decibels with respect to a milliwatt). A robust mid-latitude thunderstorm quite often exceeds 65DBZ, and in some case's 70DBZ. It is rare to exceed readings of 50DBZ in a tropical storm. We did encounter an area of 56DBZ in one of the outer bands we crossed and the aircraft was jolted pretty good. Finally, the question of why doesn't the P3 routinely fly into hurricanes that make landfall, except in rare cases where research is being conducted? While the storm is over the water, there is very little friction except what's produced by the sea surface. However, as the storm interacts with the surrounding terrain, the horizontal uniform wind flow is disturbed. The increased shear not only introduces great turbulence to the lowest layers, but the sheared zone becomes a breeding ground for severe and sometimes tornadaic storms that could jeopardize the aircraft. Mitch was interacting with the terrain of Honduras that extended four to eight thousand feet high. During one of my walk abouts, I noted the snapshot of Mitch on the Doppler, overlayed with the geography below. The eyewall had enveloped the island of Guanaja, and was heading directly for Roatan. The wind profile showed 131 kts seventeen miles north of the eye. Hurricane Mitch had already claimed its first casualties.
The practice of leaving and returning to our seats continued for a few more hours. Once when given the all clear sign, I remained strapped in my seat and managed to get a couple minutes of shut eye. I didn't know if fatigue was catching up with me, or whether the intensity was such that my body was telling me to relax. After all, my spine had been a shock absorber for quite some time. We departed ten thousand for eighteen thousand feet. The mission called for a few more GPS sondes through the eyewall at approximately 500MB. As you ascend, the eye opens up and the thunderstorms tilt away from the core. The passes through the eyewall were still turbulent, but the frequency and magnitude had subsided. It is similar to an ocean swell wave decaying the farther away you get from the generating force. The temperature dropped and it wasn't long before the water turned to ice. You could hear the graupel striking the aircraft, but only for a short time. The work complete, we negotiated an orbit, and headed for home.
I couldn't help but notice the image on the radar screen as Mitchs' eye remained behind. Here I was 1748 miles from home charging head first into the most powerful hurricane to strike the Atlantic Basin in October, and the fourth strongest of all time. What could possibly be worse than a category V hurricane on this planet? The only other thing that came to mind was the red spot on Jupiter! I wondered just how long Mitch would allow us to poke him from every side before striking back. At times I felt more like the hunted than someone flying in a hurricane hunter. I was not there to hunt though. I was there to observe one of natures most beautiful spectacles, at the same time one of natures most furious killers. As we headed back, the moist tropical air seeping out of Mitch was already rising against the mountains of Honduras and Nicaragua. Central America's Agnes, as one forecaster in my office proclaimed, was unfolding. Parts of Central America were soon to become a "Meteorological Crime Scene." The Deadliest Atlantic Hurricane since 1780.
On the return flight I talked with several people and gained a new respect for the crew and scientists. One crew member passed by wearing a patch that signified "100" penetrations. I thought, only 99 more to go. The mood was one of excitement, but at the same time subdued. As one scientist said, after I asked him how rough this flight was, "I'd much rather be here than at the mercy of this storm on the ground," and he was right.
On the way back I rode in the cockpit and enjoyed every minute of it. A carpet of bright lights welcomed the P3 as it descended to Tampa Bay. The pilot aligned the nose with the runway as we made our approach over the water, and set down on the centerline. It took only a few minutes before everyone had deplaned. I reached the bottom of the stairs walked a short distance and said, "I would do this again in a heartbeat!'" The day was ending just as it had begun, on a beautiful weather note under the clear skies of Tampa. But tonight, I knew exactly the difference a few hundred miles had made. As we walked back to room 205, N43RF was being towed to the hangar. After a brief stay, it was time to return to the hotel. At 1215 a.m., thirteen hours after it all began, I sat down and devoured my soggy tuna fish sandwich and chips. Exhausted, I retired.
The next day a couple of us met for breakfast then
drove to the airport. As my Delta flight pulled away from the gate I heard
the "bong", looked up and saw the seat belt sign come on. With a gentle
tug on the belt, I thought to myself, this is going to be a piece of cake!
It is with sincere appreciation, that I thank the following people for this opportunity:
Hurricane Research Division:
Mr.Frank D. Marks
Mr. John Gamache
Aircraft Operations Center: Mr. James D. McFadden and Staff
Tropical Prediction Center: Mr. Jerry Jarrell and Staff
NWS Mt. Holly, NJ Mr. Gary Szatkowski and Staff
I didn't get everyones name on the flight, but those I remember and
thank are James Franklin, Mike Black, Paul
Leighton, and Rob Rogers, HRD. Jack Parrish and Stan Cyzyck from AOC. The cockpit crew.