May 23, 2012

Statistics:

Initial Target: Omaha, NE
Departure: Minot, ND KMOT 11:00 am
Arrival: Olathe, KS KOJC 10:00 pm
Intercepts: Omaha, NE
Tornadoes: 0
Hail: None
Wind: Non-Severe (not measured)
Features: Wall cloud, outflow plumes, gustnado
Miles: 871 KMOT->KBIS->KFSD->KOMA->KOJC

Summary:

Second day in aerial storm chasing trip. Cold front play across eastern Nebraska and northwest Iowa. Headed for home airport in Olathe, KS leaving Minot, ND and planning to intercept stronger, more discrete portion of forecast linear cold front MCS. Crossed cold front in the morning noting stratus and light rain on the cold side near Sioux Falls and moderate to strong turbulence, haze and convection on the warm side. Waited for storms in Omaha after refueling at Bismarck and Sioux Falls. Took off as MCS matured 30 miles to the west and intercepted discrete cell in line that went tornado warned. Noted wall cloud, outflow plumes, and gustnado, but storm did not produce any tornadoes. Wall cloud deteriorated so headed for Olathe, arriving after dark exhausted after two long days in the air.

Crew and Equipment:

Chase partners: Caleb Elliott and Phil Bates.  Equipment:  2010 Cessna 182S with Garmin G1000. Dell Inspiron Laptop.  Millenicom 760 USB datacard, Holux 236 GPS, Canon 60D with EF-S 10-22mm, 50mm, and Sony HDR-XR500v.

Video:

 

Details:

Wednesday, May 23 was our second aerial chase. After flying all the way to northern North Dakota the previous day for our first safely executed albeit tornado-less aerial storm chase, the plan was to make our way in the direction of home base, chasing along the way as opportunities presented themselves. The day's setup featured a cold front draped from central Minnesota through western iowa, eastern Nebraska, bending back into Kansas. Shear and instability looked quite favorable for severe weather on the boundary, however, veering winds on the cold front and lots of forcing meant storm mode would favor a linear MCS with perhaps embedded supercells.

We hoped to cross the cold front early before storms went up, getting out ahead of it, and then play the southern end where storms looked to be a bit more discrete as forcing was a little weaker further south. Dewpoint spreads and capping were problems on the southern end of the setup, however. Convective models showed rotating updrafts in southeast Nebraska by early evening so that became our primary target and SPC went with rather modest 5% tornado probabilities. With the large number of storms expected up and down the cold front, tornadoes would probably be far and few between.

We were up not terribly early, exhausted from our previous day's flight. A quick continental breakfast and coffee from the motel and we walked across the highway to the airport to get the plane greeted by sunny skies, with some high cirrus and light surface winds. A great day for flying.

Minot Interational Airport with customs for flights to and from Canada:

Walking out onto the ramp, there were a bunch of neat aircraft sitting out. An antique Cessna 150 on the left, the yellow ones are a couple of crop dusters, the one in the back with an old radial engine and the closer one with a new turbine. The silver one a World War II T-6 Texan trainer.
Caleb and Phil walking around our Cessna 182 doing a preflight check to make sure everything is in order before we take off.
Phil loading up some gear, and Caleb climbs up to check our fuel:
We took off from Minot and headed south to our first fuel stop, Bismarck. Departing Bismarck, we circled the town so Phil could get some stock footage of a town from the air:
Our next stop was Sioux Falls. The cold front was passing through there and we flew into the back end of it before we arrived. Clouds thickened up with a couple different layers of stratus and cumulus. We flew through some rain along the way, but the air was pretty smooth and we were able to maintain good visibility.
Phil and Caleb discuss the weather conditions as we fly between different cloud layers en route to Sioux Falls:
A neat, meandering creek I spotted from the air:
We flew into Sioux Falls, staying just long enough to refuel before departing. I spotted a row of F-16 fighter jets parked on the ramp as we took off:

The Garmin G1000, which makes flying in this 182 a real treat:

We crossed into the warm sector after we left Sioux Falls. The air was hazy and hot with slowly building cumulus, the perfect weather for turbulence, and wow was it bumpy. We got jostled around the entire way to Omaha, our next fuel stop. We hit one bump that was so hard, my laptop flew up several inches off the seat. Caleb and Phil were ducking so they didn't bang their heads on the ceiling. I had taken some air sickness pills, but too late, and I was getting super green. I kept my breakfast down, but by the time we landed I was so nauseous I was completely useless.

We were in turbulence all the way until we were down on the runway in Omaha. Surface winds were howling, but Caleb did a nice job on the landing and we had some super large runways to work with as large airline traffic flies in and out of the airport. We taxied over forfuel and headed into the super plush office, frequented by executives in corporate jets. I layed down on a leather couch for a few minutes to recover from being airsick. Even though I'm a pilot, I still get easily motion sick, not a good thing for aerial storm chasing. Storms quickly lit up along the cold front. I thought Phil and Caleb would have to leave for me the aerial chase as I wouldn't be any use air sick, but after laying down for a couple minutes, I quickly recovered. Phil and I took the courtesy car, this time a nice new Lincoln or Cadillac, out of the airport and picked up some Subway. Phil got his usual meat and cheese, absolutely no vegetables sub, and I got my standard veggie sub, absolutely no meat and cheese. We scarfed it down in the airport office before stepping outside to watch the building storms. The western horizon was darkening and an anvil stretched high over Omaha. The last few planes were scrambling to get out of the airport before the storm hit. We were gassed up and ready to go, but waited a few minutes for the line to mature before we made a move, the storms still a good 30-40 miles to the west and moving slowly northeast. We had some time. When some semi discrete and severe warned storms started coming up out of southeast Nebraska, we decided to go for the aerial chase.
Cleared for take-off we departed to the west and made for the line of storms. West of Omaha, a line of updraft bases came into view, blue in front of a bright orange sky as the early evening sun was getting low. Our storm went tornado warned, and the chase was on. Our first glimpse at a developing wall cloud several miles west of Omaha:
We started our circle pattern in front of the storm that worked so well on our first aerial chase the day before. The air was a little bumpier today, probably due to the hot, unstable warm sector or dynamics of the cold front. A wide angle shot showing a wall cloud with tail cloud (center) feeding off the rain cooled air of the forward flanking precipitation core (right) and updraft base above it (top):
Another wide shot of the tornado warned storm over eastern Nebraska:
We worked in a bit closer on our circles and I switched over to my 50 mm lens to get a little tighter on the structure shots. A prominent rear flanking downdraft precipitation core was fanning out behind the wall cloud:
The wall cloud tightened up into a small blocky shape as we continued to circle. A plume kicked up underneath the wall cloud. A possible tornado, it turned out to be just a large gustnado or outflow plume.

The plume continued for awhile as the wall cloud fanned out again cut by a rear flanking downdraft:

As the storm moved east-northeast, our circles were taking us closer and closer to controlled Omaha airspace. We'd have to get clearance from Air Traffic Control before flying into the airspace. Omaha is a busy class C airport with a lot of large jet traffic, and we expected the controllers to be rather tight with traffic, especially with hazardous weather in the vicinity.

We tried anyway and Caleb made contact with an Omaha controller giving our tail number and position before asking, "We'd like to fly a race track pattern in front of this tornado warned storm." There was a long pause after what must have seemed like an absurd request followed by what I thought was a slightly incredulous response by the controller: "... approved."

We were surprised we were allowed to continue our aerial chase through controlled airspace. Most of the traffic had probably ceased as severe weather approached the airport, however, pilots not daring to land or take off in dangerous wind shear.

A rather chunky looking wall cloud with a large plume of outflow evident on the left as the rear flanking downdraft surgest out underneath the storm:

Glowing bands of precipitation catching the setting sunlight behind a fanning out wall cloud, as the storm moves over a series of small lakes:

We continued our circling pattern, edging in closer on a couple passes. We hit some turbulence, probably bumping into some outflow the storm had shed so we decided to back off and play it a little more safely.

Another big swoosh of outflow underneath the storm's rear flanking gust front as evident as the lighter area on the ground:

We were well above and away from these surges. Had we tried to fly underneath the storm's updraft base and encountered one of these surges, the results could have been disasterous. Severe turbulence can damage aircraft, and the wind shear could have sent us out of controlled or caused a drop in lift sending us into the ground.

Another close up of the storm's outflow, kicking up a large plume of dust with powerful straight line winds.
The wall cloud seemed to shrink in size, but for awhile it took on a nice block shape. Some pointy scud underneath even made it look like there was a large funnel, but I don't believe there was much if any rotation to it.
The storm lost it's warnings and the wall cloud detached from the updraft base. We gave it a few more passes but it appeared that our storm was dying.
The last shread of our wall cloud is pushed out from the storm as a stubby roll cloud, the left edge curling backwards as it's pushed out by the storm's outflow. Our storm was definitely dead, and we turned our tail to it and started heading for home base in Olathe, KS.

The air wasn't as bumpy as it was before with the sun going down, and we arrived in Olathe after dark, exhausted again after two long days in the air. We secured the plane, Caleb headed home, and Phil and I headed back to the hotel for a much needed sleep and day of rest. Tornado probabilities looked to be higher in northern Wisconsin the next day, but it was just too far out of our range to make a one day flight that far north only have to have to fly back to Kansas for the rest of the chase trip. Storm mode and interfering convection looked to be hinderances to an aerial chase as well.

Conclusion:

Our second aerial chase fared out even better than our first storm structure wise, despite low expectations from the cold front setup. No tornado, but we captured a dramatic looking wall cloud from a tornado warned supercell. Our encounteres with turbulence, however, made the chase rather demanding on the body. I'll definitely make sure I take ginger and dramamine well ahead of time on the next aerial chase. Overall, the day was very much lacking in tornado activity, so we were quite pleased with our wall cloud intercept.

 

Lessons Learned: 

  • Take dramamine and ginger pills long before the aerial chase begins, as turbulence in unstable air can lead to motion sickness.

  • Air traffic controllers are helpful and informative, possibly allowing aerial chases through controlled airspaces.