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WEATHER JOURNAL
Come back often for updates as Dave Carroll and his group of storm chasers check in with reports from the road. May 25 On the road back to Virginia now, ending the trip with a very serious tornado outbreak. In hindsight, the storm in Furnas and Harlin Counties in Nebraska was a thought-provoking experience. Words such as "fierce" or "intense" simply cannot describe it. I have been around many supercells before, but this particular storm seemed to be exceptional in its overall violence. Fortunately the tornadoes stayed rural, but some small towns still suffered.
Mid-morning we headed up to Grand Island, 30 miles north. We analyzed the current weather conditions, and simply camped out at a travel plaza for several hours, checking data and looking at the developing cumulus field. Within two hours of our arrival at the travel plaza, we were joined by three DOW's (Doppler radar-on-wheels) from Penn State, their support crew, and a team filming an IMAX movie. The local people began feeling pretty nervous when our vehicles began gathering in this location. Being a Penn State graduate, Ethan knew some of the chasers in the DOW's, and walked over talked with the crew. Everyone on the chase team passed the time talking with the other chase teams and some of the locals. A tornado watch was posted for the area at 3:30 pm; around 4:30 storms began to fire, and we were on the move. Travelling southwest toward a developing cell, Seth was active on amatuer radio with other Skywarn spotters. A tornado warning was issued for Furnas County, Nebraska, one county to the west. We raced toward the town of Holdrege while spotters were reporting a large tornado on the ground. Seth was talking to another spotter travelling westward on the same road as our chase team when the wall cloud came into view. We elected to make a move southward well ahead of the visible wall cloud to reach the southern side of the cell. It's track was east-northeast, so we knew any southbound road would be a good escape. Heading south of Holdrege we passed the first DOW scanning the storm, and in the distance we could see what appeared to be a large tornado under the wall cloud, but it was too far away to be sure. We pulled off the road to see tornado development take place, with a large cone-shaped lowering under the wall cloud....then a pronounced funnel reached toward the ground and rapidly grew into a large tornado. The debris cloud around the tornado near the ground was clearly visible. As the tornado approached, we decided to roll down the road further, passing the second DOW which was scanning the mesocyclone. The tornado became wrapped in rain and hail, and was VERY difficult to see. We picked up speed going southbound when the chase vehicles were slammed with winds estimated at 80mph.
For a while I was worried about the vehicles at the end of the line. We were already south of the tornado, which spun up a satellite vortex only 200 yards off of the road to the right of our vehicles. At one point on our video, Maria can be heard saying "GO DAVE, GO!!! GO!!!". The EMS vehicle in front of us was NOT traveling quite fast enough for us! The end of the caravan was due east of the new vortex, and the new tornado was racing eastward. Daniel noticed that the DOW's at the end of the line made it through. We turned east on the south side of the storm, and contacted Kevin Myatt, working his copy desk job at the Roanoke Times, for radar support. He reported a hook-echo on the back side of the storm, and we saw three funnels form and dissipate from a new wall cloud. Emergency vehicles were everywhere, with roadblocks on roads to the north. We eventually turned north to come up behind the storm again, but slowed down when we began driving through the damage path. Rural farmsteads were hit hard, and we stopped to see if one family needed radio assistance via Seth's connections. They told us that they rode out the storm in the basement, and the back side of their home no longer existed. In fact, a young couple visiting the area abandoned their vehicle and raced into this same family's basement. Debris was everywhere, and at one point we passed a trailer literally wrapped around a telephone pole. Downed power lines, mangled irrigation equipment, and parts of roofs, silos, and sheet metal were everywhere. Some people took huge losses. It is really a strange feeling to see something so beautiful, but so incredibly destructive. Kevin advised us on a new storm firing in Clay County just east of our location, but nightfall was closing in, so we decided to call it a day. Adrenaline had been pumping in overdrive for over 4 hours, and the team was exhausted. Sunday we begin our long drive home. May 19 Confidence in models is running rather low today, as the "significant" severe weather episode that was predicted failed to produce a single thunderstorm within the area of highest risk in Nebraska and Iowa. At this point, we are simply going to go on our own forecast, and ignore the risk assessments. Thursday we will travel westbound toward the central/western KS/NE border, hoping that some sun will kick in on the tail end of the front. Shear looks good there, but CAPE is somewhat limited. BUT, that is what we had running on Sunday when we rolled through a supercell. We have a long travel day ahead today. Everyone had high hopes for Wednesday, so it was a pretty frustrating day to see the only tornadic storms occurring near the Canadian border -- WAY out of range of the target area. We forecasted well again, stopping on the roadside and playing the waiting game. The SPC put up a severe thunderstorm watch box for the location where we waited, and then the local NWS office issued a special weather statement for "rapidly developing supercells" in a four county area adjacent to our location. The storms fired, and we hit the road, passing the Doppler-on-wheels caravan again, but the storms just wouldn't fire. Towers would climb, and then die. We couldn't see how this was happening, with very strong instability being forecasted for the area ... but then again, as Bill Benson at school always says after a busted forecast: "weather occurs in the atmosphere, not in models." The overall tornadic situation doesn't seem favorable for the next few days, but we will continue to place ourselves in the regions of best instability and shear ... and see what happens. May 18 I'll start today's update with Kevin Myatt's e-mail contact: "If the cap gets broken in western KS today -- there could be a couple of mighty, mighty supercells. If not, just hot and dry. The thrill of victory -- or the agony of defeat. I already see some hail reports in Kansas this morning. Hope you pick the right road. --Kev" Oh, that "agony of defeat." Aactually, today was a pretty good day: no severe weather going on, but a good forecasting day, which is one of the main reasons we are out here...trying to use data to forecast and target a position. Much of Kansas was strongly capped today, inhibiting storm development. However, we saw an area of high instability in south-central and southeastern Kansas, so we decided to head there to see if anything decided to fire. While we were driving toward Wichita, the Storm Prediction Center put up a meso-discussion for areas around I-70, but we just couldn't see it: it was cool with winds from the east. We drove further south trying to identify a warm front, and found it near Wichita. Shortly after we were there, the SPC issued a mesoscale discussion for the area, with a possible tornado watch should convection fire. A good forecast again, we placed ourselves well. But the cap was just too strong, so we ended the day watching towers pulse upward and die in the cap. The team has really molded into an efficient weather machine on the fly. Maria, the leader of chase van 2, and myself driving chase van 1, can concentrate on the driving, without having to even think about weather analysis while rolling down the road. Ethan is really talented in noting small parameters that help target an area, and the Eric/Chase tag team is a machine when running radar on the road. Beth & Becky have manuevered us through some very rural (and unmarked!) terrain. Josh is a natural with the video cam, and has become the official "videographer" of chase van 1. Daniel shines on mesoscale analysis and radar on the road. Oh, I could never forget the ever-present Seth, kind of the McGyver of the chase team. Tomorrow (Wed.), we head to eastern Nebraska. SPC has been forecasting a possible severe weather outbreak there. May 17 Disappointment is part of the deal. Sunday evening, Ethan, Maria, Daniel, and I forecasted where we thought we needed to be on Monday: we targeted Hays, Kansas, as the best location for the combination of CAPE/shear/and moisture convergence. We headed south out of Nebraska into Kansas, and shifted westward along I-70 to Hays. We positioned ourselves south of Hays, and pulled off of the road to simply watch. We contacted Robin Reed at WDBJ-7, and he provided real-time information on the cumulus towers and where skies were clearest. The atmosphere was capped, so we played a waiting game, watching to see if any clouds in the growing cumulus field could break through. Around 4 pm the first towers broke through the cap, and the clouds raced upward. We concentrated on three towers, watching them closely. As one died we looked closely at two: one was widening at the base, and the other appeared to be pretty disorganized. Calling back to Scott Frye, the storm to our west looked the best on radar early. Yet another call to Steve Keighton of the National Weather Service re-inforced our location as a good one, with the front, dryline, and moisture in place. We were centered in a newly issued tornado watch. We chose the visually more promising storm. As we approached, the storm appeared to begin taking on LP supercell characteristics, and began producing the highest reflectivities in the area, probably from hail. The base of the updraft began to become better organized, so we committed to this storm even further. Forming along the dryline, it seemed to have trouble drawing moisture, and we hoped it would move further east into a moisture-rich environment. It didn't and fizzled. Meanwhile, the less organized storm to the east was moving along a frontal boundary, and began tapping into more moist air. This was the storm of the day. We raced back toward Hays, passing two Doppler-on-wheels that had been monitoring the storm we had chosen. We could clearly see the back of the Russell County storm, which now had a tornado warning. Logistically, we couldn't reach it. We had pinpointed a place to chase the previous day, and a tornadic storm formed only 12 miles from our target point ... and yet we couldn't reach it! We saw nice storm structure, but everyone was visibly frustrated. All part of the game. Storms may fire along the front on Tuesday, and we will be there again. May 16 |
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Our final day of chasing ended up being an active one. The morning began very quietly, but the Storm Prediction Center began predicting a major outbreak early. We had positioned ourselves perfectly, staying in Hastings, Nebraska overnight. 
Larger and larger hail began falling in the area, and curtains of rain wrapping around the circulation were SCREAMING across the road. Soon, a small caravan of vehicles were heading south on the only path of escape. North was not an option, as radar indicated hail to 4.5" falling from the storm north of the updraft. An EMS vehicle was directly in front of our team, with other local EMS/law enforcement vehicles direclty behind, with the two DOW's and their support crew coming in fast at the end. 
After racing east-west on I-80 (we humans are a stubborn lot when it comes to second-guessing your previous forecast) a couple of times, we finally stayed the course west of Grand Island, Neb., on our original hunch and caught up with an intense supercell.|
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