2014-5-19 REPORTS: NE

[John Gnuechtel]

I targeted Ogallala today, figuring I'd just go to the top of the dry line, be northish of the surface low, and under the best instability in that vicinity. The first storms went off in southeast WY, but couldn't hold together. Then a second round fired, and came at Ogallala on an east-southeast track. Two supercells went, both curving right. I got the northerly one as it died out north of Ogallala. It was way elevated, but still had nice features. I was happy to catch it. I finally got one of those lightning-lit mesos.

 

[John Wetter]

Had a great chase today. Started the day in Kearney, NE and headed west at a leisurely pace, stopping at the rail yard in North Platte and a couple stops along the Oregon Trail with Windlass Pass and Ash Hallow. I was liking the moisture (for what it was) but worried if it would get far enough west. Models were consistent with some storms starting in eastern Wyoming and heading east into better moisture. Two supercells got going just on the Nebraska side of the line and headed East-southeast. The panhandle didn't disappoint with great structure! Big bowl updrafts and though one storm become tornado warned while we watched it, it was very elevated. I called the local NWS office then to let them know and we had a conversation about the storms. Soon after this north storm weakened so we dropped south to the next supercell which again had great structure and as the sun set had some great lightning opportunities.

My pictures from the day.

 

[Greg R]

Great pics, guys.

I got into the game a bit late today but manage to catch up with those same cells. Here are a few pics... the first of which was that cell that prompted the tornado warning. The wall cloud shortly thereafter became rain wrapped. The latter is the southernmost storm.

 

[Bill Hark]

I started the day in Scottsbluff, Nebraska. The forecast was difficult for this marginal day. Most of western Nebraska had north to northeasterly surface winds. The best CAPE was predicted to be in south central to eastern Nebraska where none of the forecast models showed the cap breaking. There was some disagreement between the forecast modes but in general, storms were forecast to form in Wyoming and slowly move easterly across the Nebraska panhandle. The exact placement of the storms was unclear. Tornadic potential was very low. The SPC initially had a slight risk (2% tornado) that was later downgraded to “see text” and less than 2% risk of tornadoes. My strategy was to pick a spot with decent road options and wait for the storms to approach. Hopefully, one or two would become dominant. My biggest concern was storm formation ahead of the main group, leaving me scrambling to catch up over a poor road network. I didn’t station myself further east as the best features would probably occur earlier in the storm life cycle and loosing daylight would become problematic.

I had a leisurely lunch and then meandered southeast to Bridgeport. This town had decent road options north and south along with nice photo opportunities. Weak storms were already firing to the west as expected. I stopped at the Chimney Rock visitor center and spent time learning about the pioneers who traveled through the area in wagon trains. Chimney Rock was an important landmark in their journey. I tried to imagine the difficulty in traversing these long distances on foot and covered wagon. In the distance, I could the mushy storms. As I walked out of the visitor center, I ran into Chris Collura who had just driven in from Chicago to chase over the next few days. After chatting, I drove to a nearby wildlife reserve and watched the birds over the beautiful landscape while periodically checking the status of the storms to the west. Their progression was slow. I did notice one area of consolidation to the west, and I suspected this might become the southerly edge of a group and would have the best chance for development. I drove south and west on the scenic route 88 passing by Courthouse and Jailhouse Rocks. The storms were not very impressive. Later, there was one more dominant storm approaching 71 to my northwest, but it started to die. I waited at the intersection of 88 and 71. The seemed hopeless for severe storms when another area looked interesting to my southwest. A cell was becoming more isolated. I dropped south as that storm strengthened and began to rotate. I stopped several times to take pictures. The road network was poor and I just let it come to me. There was even some brief inflow. As I approached the intersection of 71 and I-80, large quantities of outflow dust approached my position. I had to keep dropping south and then east on I-80 to avoid the dust. I could hear the swirling dust when it was close. I hopped to see a gustnado. The structure of the storm was amazing. In retrospect, I should have blasted east sooner to get a better view of the whole storm. I was too close, and could only stop for brief periods as not to get overwhelmed in dusty outflow. My progression eastward was slowed by a long area of construction and blockage of one lane. As darkness arrived, I ended the chase a continued eastward to Ogallala where I had already booked a room. At Dennys’s, I ran into several chasers and then had dinner with Australian chaser Dan Shaw. He had an beautiful shot of the storm from a bit further away and using a wider angle lens than I had available.

Overall, I am very happy after a great storm intercept on a marginal “see text day.” I have some great images and video though I could have done better. I blew some highlights on many images and had not taken them in RAW format. At some point earlier in the day, I had switched to jpeg only. Ughh. I also should have gotten a bit farther away to get more views of the entire supercell.
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images (all times mountain daylight)

Chimney Rock, storms to the west. 2:23 PM


http://www.harkphoto.com/051914pinnaclerockDSC_7139.jpg

Isolated farm near Bridgeport, Nebraska

http://www.harkphoto.com/052014isolatedfarmDSC_7146.jpg

Courthouse and Jailhouse Rocks along 88

http://www.harkphoto.com/051914courthousejailrocksDSC_7153

Tumbleweeds against a bridge on 88. Storms to the west. 5:37 PM

http://www.harkphoto.com/051914tumbleweedsstormyskiesDSC_7183ad

Along 88

http://www.harkphoto.com/051914cowsundertreeDSC_7165.jpg

6:03 PM, view west along 88. That looks interesting to the southwest

http://www.harkphoto.com/051914developingstormDSC_7189

6:13 PM. View to west from 71 south of Scotts Bluff

http://www.harkphoto.com/051914devsupercellDSC_7191

6:30 PM. Nice inflow features on supercell. View to west from 71

http://www.harkphoto.com/051914supercellDSC_7201

Blowing dust is getting close, 6:55 PM

http://www.harkphoto.com/051914blowingdustIMG_0803

Blowing dust and oil rig

http://www.harkphoto.com/051914blowingdustbyoilIMG_0810

View to NW from I-80 of storm 7:05 PM

http://www.harkphoto.com/051914stormapproachIMG_0818

Supercell with sunset, view to west on I-80 7:17 PM

http://www.harkphoto.com/051914supercellDSC_7254

Truck escaping storm on I-80 7:18 PM

http://www.harkphoto.com/051914escapingfromstormDSC_7278

Bill Hark

 

[Tim Carley]

It looks like Bill Hark and I had very similar days! (I got Chimney Rock pics in that morning also) I never knew that a tumble weed could sound so loud when it hits my truck. Just didn't expect the storm to intensify so quickly. Had a blast, though.

 

[cdcollura]

Good day all,

Sorry on the very late post on this day, but it was a good day, despite the marginal setup, so I'll post my chase report below.

Summary: May 19 was the first chase day of this trip (May 19 to 22), and was a marginal chase day that turned out to be quite fun with some beautiful supercell storms intercepted in the western part of Nebraska near Scottsbluff and points southeastward. I forecasted and found the best place to be was from the SW Nebraska panhandle area and northward to near Scottsbluff. The SPC (Storm Prediction Center) also had this area initially in a very small slight-risk area, with 2% tornado, 5% wind, and 15% hatched (significant) hail probabilities. As the day progressed, this was downgraded to a see-text (but a bit "under" forecasted). I stuck with the target area, heading west out of York on I-80 to Ogallala, then northwest on Highway 26 to the area near Scottsbluff. I stopped at Chimney Rock where I saw Bill Hark, before continuing to chase developing storms near the Gering / Scottsbluff area. By later afternoon, storms finally became more established, with a beautiful LP supercell observed from near Harrisburg along Highway 71 and southeastwards via Highway 52 through Dix and to I-80 east to near Sidney and Chappell. I wrapped up the chase near Chappell, Nebraska by about 9:30 PM and headed east on I-80 to Big Springs for the night.

In the graphic above, the SPC convective outlook is shown to the left, depicting a very small, if not one of the smallest, slight-risk outlooks over the Nebraska panhandle. This area also had a tornado probability of 2%, with a 5% wind and 15% hail (hatched) probability. Later in the day, this area was reduced to a 'see text', and the tornado probabilities were removed as well as the significant hatching for the 15% hail with the 5% wind remaining. In the middle image, we see the mesoscale discussion in the same area that was issued (MCD 620). To the right is a NWS reflectivity radar image of an LP supercell storm that formed south of Scottsbluff and tracked ESE to near Chappell, NE.

Above: Strong rotation and RFD dust getting kicked up by the intense mesocyclone as it was entering southeastern Banner County, Nebraska.

Above: Here is a view from near Kimball, Nebraska looking east and upwards towards the intense updraft of the supercell storm. The hail shaft, with at least 2" hail, can also be seen just above the end of the road and to the left. Note the inflow banding / tails to the right!

Report On This Storm (May 19, 7:30 PM): Observation and indirect penetration of a very severe thunderstorm from near Harrisburg in Banner County, Nebraska and Highway 71, and points east and southeast through Dix on Highway 59 and eastward along Interstate 80 towards Chappell in Deuel County. The storm was a high based but intense LP supercell storm. The storm had a very striking visual appearance, including a high based wall cloud, striations, RFD clear-slot, and "mother-ship" appearance. The storm was indirectly penetrated, and RFD winds of at least 70 MPH with blowing dust was observed. Heavy rains, hail to ping-pong ball sized (1.25"), and frequent lightning was also encountered. The main core had hail up to 2.5" (tennis ball sized). Some tree and roof damage was noted in Dix in Kimball County just north of I-80. Conditions causing the storms were surface heating, frontal boundary, upslope wind flow, a low pressure area, and an upper trough. A 2009 Ford Escape was used to chase the storms. Documentation was digital HD video and stills, and audio.