Ann McCarthy, NSSL Meteorologist and Web Manager

"I had the opportunity to join the MEaPRS scientists on the P-3 the Sunday of Memorial Day weekend. The flight lasted about 8 hours. We left Oklahoma City at 10 pm Sunday and returned around 6 am Monday morning. Our flight took us to the Oklahoma/Kansas border and north to Wichita. During the first few hours of the flight we bumped around through strong convective storms hitting several updrafts in excess of 10 m/s (23 mph). Later toward morning the flight was more smooth. We spent time taking passes at various levels through a stratiform deck. I did find out, however, that the melting layer can be rather bumpy as well.

I had access to a workstation with displays of the two airborne Doppler radars, flight information, and various atmospheric parameters. Having the opportunity to view all of the data while flying was incredible. The one difficulty I had was adjusting to the radar. Every time the plane took a turn there was a new display. It was not always very clear to me where we were in relation to the storms or the ground.

That night, I was able to see, on radar, a hook echo near Enid and a bow echo with book end vortices, spectacular lightning, St. Elmo's Fire, and interesting cloud particles with the cloud physics instruments.

Several days later, I learned that Greg Carbin from the Storm Prediction Center took a similar flight. The following is his account of the trip. His experience is much like mine, including getting sick. I don't think I could word it any better."

Greg Carbin, SPC Mesoscale Forecaster

We departed Oklahoma City at 8pm CDT (01 UTC) and headed NW toward the Kansas/Nebraska border where a warm front was developing. Severe storms had already developed over eastern Colorado, the Texas panhandle, eastern New Mexico, and northern Oklahoma. An MCS was expected near the warm front and the plan was to fly transects through the stratiform precipitation region of the MCS, generally along and WNW of the strongest storms.

The outbound flight was smooth at a cruising altitude varying from 13,000 to 16,000 feet. The aircraft is equipped with an amazing array of electronic equipment, and I was lucky to get a window seat and workstation with two high-resolution monitors where I could view a number of aircraft and atmospheric parameters. In addition to the display of tail-mounted and belly-mounted radar data, I could view live video from the nose of the plane, the short and long range track on a LAT/LON grid, the graphical output from the cloud micro-physics sensors located under the wings, and a complete listing of aircraft speed, altitude, pressure level, ambient temperature, dewpoint, and electric field strength. Distance to and from various locations was also displayed. Most of the flight was conducted at just under 500 mb. The winds at this level were from the SW at speeds of 25 to 40 KT.

After cruising at over 230 KT for a little over one hour, we arrived over extreme northwest Kansas. The setting sun was highlighting some very impressive thunderstorms to our east and west. The largest storms were located over eastern Colorado with another cluster of storms to our north, over southwest Nebraska. Unfortunately, the developing storms over Nebraska meant that we would be leaving the NSSL ground-based sounding vans behind over central Kansas. The three vans and three balloon trucks had left Norman earlier in the day in an attempt to intercept the developing MCS at the time of our fly-through. With the storms developing farther north, there would be no ground-based balloon soundings tonight.

The flight director and principal investigator decided to fly to the storms that were over southwest Nebraska, near Ogallala. I was able to monitor the flight path and the Doppler radar as we approached the area from the south. This part of the flight was quite turbulent and my stomach was really starting to turn. Despite having a single dose of Dramamine in my system, I made the mistake of having a snack and a soda during the outbound leg of our journey. The diet Pepsi was starting to rumble and I had little doubt that some of it was going to come back up. Luckily, the bouncing subsided a bit after we got into the large stratiform precipitation area behind the more intense cells.

The seatbelt sign went out and I took the opportunity to walk the aisle and grab an air sickness bag. About five minutes later I dashed into the lavatory and put that bag to good use. After that, and a short rest in an open seat with some leg room, I felt much better.

During my air sickness episode the plane was tracking back and forth on SW-NE and NE-SW legs, through very heavy precipitation and lightning. At times we could hear the rain and small hail pelting the cabin of the plane. Occasionally we would hit an updraft, followed almost immediately by a downdraft. Data collection continued uninterrupted through this phase of the flight. Conrad Ziegler, as chief scientist, coordinated with the nowcast team back at NSSL/SPC, the ground team over Kansas, and the flight director. Tom Shepherd, seated next to Conrad, expertly manned the tail and belly radar systems while Terry Schuur monitored and logged the output from the cloud microphysics equipment. The NOAA Corps flight crew included three members on the flight deck, as well as a navigator, flight director, and at least three other electronics and avionics technicians.

While wandering the aisle recovering from my vertigo, I was impressed by the number of experiments and research projects that this NOAA P-3 has been involved in. In addition to being used routinely for very important hurricane reconnaissance, the walls of the plane are plastered with colorful emblems from numerous field projects including FASTEX, GEWEX , ERICA, TOGA-CORE, and GALE to name a few. There were stickers from the major media including NBC News, CNN, and ABC, and a framed fancy certificate attesting to the NOAA crew's bravery in consuming some of Norway's Golden Elixir, whatever that might be.

As the lightning and turbulence continued I made my way back to my original seat and on the way talked with Terry about some of the cloud microphysics data. The details of the equipment are rather complicated, but the display was very interesting to watch. As we flew through cloud you could actually see representations of the cloud particles and their sizes on the display. At one point we flew through virga, or perhaps anvil debris, and we observed perfectly-shaped six-armed dendrite crystals. A quick check of the flight information showed that these crystals were actually occurring at temperatures a little less than -5C, near 550 mb (rather warm and low). We later climbed higher (up close to 400 mb, or 19,000 feet) where the temperature dropped to -16C, and the cloud particles were almost all ice and very small. Other parts of the lower cloud had relatively huge cloud droplets, and the bigger the particle, the more oblate the shape on the display.

NSSL's Ann McCarthy at about 1 a.m.

Occasionally we would hit an updraft, followed almost immediately by a downdraft. Data collection continued uninterrupted through this phase of the flight.

Chief scientist Conrad Ziegler

About half-way through the flight the plane completed a "PURL" maneuver which allows the Doppler radar to record 360 degrees of data which can later be used to calculate wind divergence and other kinematic fields (see: http://www.nssl.noaa.gov/~schuur/meaprs/opfig10.html for more info). Shortly after this we headed east toward North Platte, Nebraska. I went up into the cockpit to observe St. Elmo's fire emanating from the large electronic field probe that sticks out about 15 feet in front of the aircraft. When I got onto the flight deck there was a blue haze around the end of the probe; less than a minute went by before a 4 to 5 foot spark came off the end of the probe and the blue haze disappeared. A short while later we broke out of the clouds and the moon was highlighting the undercast. The towering CBs became shadowy gray pillars in the distance, outlined occasionally by a pulse of white lightning.

We turned and headed south for home shortly after 1 a.m. CDT (06 UTC). After takeoff with a full load of fuel, the plane had to use 6 hours worth of fuel in order to reach a safe landing weight. On the trip back I enjoyed talking with Terry, Conrad, and Mike Biggerstaff from Texas A&M. I also revisited the cockpit to enjoy the peaceful view of moonlit undercast blanketing the Great Plains below us.

As we approached Oklahoma City it was interesting to watch the increasing head winds of the low level jet. We encountered the highest wind speeds of the flight (about 60 KT) at about 2 km altitude just north of Oklahoma City. The plane touched down a little before 2:30 am CDT (0730 UTC).

According to Conrad and Terry, this flight was a bit shorter and a lot less bumpy than other flights that have been completed during the MEaPRS experiment. There are approximately 40 hours of flight time left for the experiment, and the researchers are still hoping for an MCS to track directly over the Oklahoma City area so that they can collect detailed aircraft data and ground-based polarimetric radar data (from NSSL Cimmaron radar).

For more information contact Greg Carbin at: greg.carbin@noaa.gov