NOAA Hurricane Hunters analyzing southern storm radar data, cloud structures from 8,000 feet

HUNTSVILLE, Ala. - Here in the Tennessee Valley, features like these (video, above) happen regularly when thunderstorms develop in the region.

But from 8,000 feet in the air, its easy to see the shelf cloud span for miles.

Shelf cloud as seen from Hurricane Hunter airplane. (Photo: WHNT News 19)

But why fly Hurricane Hunter aircraft into severe weather -- over land, particularly the Southeast?

“It's not a new concept.”

NOAA WP-3D Orion Hurricane Hunter Airplane. (Photo: WHNT News 19)

Dave Jorgensen and Conrad Ziegler are research meteorologists at the National Severe Storms Laboratory in Norman, Oklahoma. They are the first researchers to successfully develop the method of flying WP-3D Orion NOAA Hurricane Hunter aircraft into severe weather environments.

"[WP-3D Orion aircraft] have been used in hurricanes quite successfully, so we thought we could bring them out here and use them to gather data on these kinds of storms," Jorgensen explained.

Ziegler elaborated a little more on the history behind the idea.

Fuselage radar located on the underbelly of the WP-3D. (Photo: WHNT News 19)

“Dave Jorgensen was one of the first pioneers to use the new NOAA Hurricane Hunter Aircraft with their radars, in the mid-1970s, to actually figure out how you would study a supercell thunderstorm by flying "legs" -- along one side and then going up the other side -- and then combining the measurements from the onboard radar, the beams, to determine the wind fields. Those were the pioneering concepts that were laid out in the early 70s," Ziegler explained.

“But by the early 90s we refined those concepts of how to obtain wind fields from these two beams, one pointing aft one pointing forward -- relative to the direction the aircraft is flying -- and so we could fly single legs, combine those two wind measurements and get the 3-dimensional airflow within the storms," Ziegler continued.

Doppler radar located in the tail of the aircraft. (Photo: WHNT News 19)

"So we applied what we learned about using the P-3 in a tornado experiment called VORTEX 94 and VORTEX 95. It was really the first of the VORTEX experiments, and we flew the P-3 in both of those years."

“It’s not a new concept," Jorgensen added.

"We have upgraded the radars considerably, since those times, so that we can get much more accurate and much more higher resolution measurements when we’re close to the storms."

"That's beautiful..."

Observing the weather from above gives a different perspective of storm structure, both visually and within the data.

Tail Doppler Radar (TDR) from the NOAA WP-3D Orion Hurricane Hunter airplane. (Photo: WHNT News 19)

“We’re interested in VORTEX-SE in what causes severe weather — strong straight line winds, hail, rotating updrafts, maybe tornadoes," explained Ziegler.

“We want to obtain observations that will allow us to understand what are the internal airflow structures within the storms, and how do these airflow structures relate to severe weather forming within the storms.”

And the secret to why some storms become severe or produce tornadoes may be located within one and a half miles above the ground.

As the WP-3D Orion flew parallel to the Mississippi River, one particular storm caught everyone’s eye:

Possible wall cloud observed via NOAA Hurricane Hunter airplane. Photo taken at 6:18pm CT on Wednesday, April 26, 2017. (Photo: WHNT News 19)

"That's beautiful...May I see that?" Ziegler asked, looking at the photo (above) and videos of cloud structures captured while as the Hurricane Hunter aircraft flew within 5 miles of the storm.

“So what this is [describing the protruding cloud feature and striating cloud structure]…down low, the rain cooled precipitation called outflow is coming out away from the aircraft. So you’re seeing this lowering, which is actually air probably from the outflow that is being drawn up into the powerful thunderstorm updrafts," Ziegler explained.

"The most difficult thing is not necessarily the turbulence..."

To be clear, chasing severe storms in a Hurricane Hunter airplane is not for the faint of heart -- or for those with a weak stomach.

But the researchers share that the greatest challenge in the air is similar for those who chase on the ground. Below, Jorgensen recounts his experience from the Wednesday, April 26, 2017 mission over the Mississippi River Valley.

View from the cockpit of the NOAA Hurricane Hunter airplane. (Photo: WHNT News 19)

“We went out there initially to find isolated storms that would hopefully rotate and produce severe weather on the ground. What we found instead was these quasi-linear convective systems. They’re not continuous squall lines, they are consistent embedded cells. So what the goal was was to get as close as we could — within about 5 miles — of the leading edge and to be able to fly back and forth on these little short legs so that we could take measurements of the air flow throughout the storm," Jorgensen explained.

Nose radar imagery, which pilots use to navigate toward and away from storms. (Photo: WHNT News 19)

“We were quite successful until we got into a situation where there were so many new storms popping up all over the place that we could not fly a straight leg. So we chose a different segment of that line that was farther to the south, and we had hopes that that would produce severe weather because the shear and the instability were higher down south."

"As we got down there, we also found ourselves in a situation where we just could not fly. It was so unstable. There were clouds going up everywhere. So finally we identified a storm near Little Rock and north toward Memphis — that did hold together, and we were able to stay on that storm for about an hour."

Even with decades of research experience, forecasting where severe weather will occur is still a challenge.

“The most difficult thing is not necessarily the turbulence, though this flight was rather turbulent because of the all the new stuff that was growing around,"Jorgensen stated. "It was really trying to determine the best storm to study.”

“To know which storm is going to produce the severe weather is some what of a guessing game," he admitted.

It is why the NOAA Hurricane Hunters will continue to fly to -- and around -- severe storms in the Tennessee Valley in support of the VORTEX-Southeast research project this spring.