NE Panhandle/Northeast CO Tornadic Supercell: Comments

[Mark Farnik]

Well, I was kind of bored and thought I would start a new topic on yesterday's freak southeastward-propogating tornadic supercell that dropped at least 6 tornadoes across parts of the southern NE panhandle and far northeastern CO.
It was strange because the setup wasn't really conducive for supercell development, let alone tornadoes, and the area the storm tracked in wasn't even under Slight Risk (though the Panhandle was under a severe thunderstorm watch from about 3 p.m. MST on). It formed about 4 p.m. and rapidly augmented into a monstrous classic supercell that rolled lazily southeastward at 10 to 15 mph for most of its lifecycle. It didn't weaken until about 9:30 p.m. (of course right when me and my dad had driven 90 miles to catch up with it in hopes of it giving birth to one more vortex; LOL :roll: ) All in all a very oddball storm which caught everyone off guard.
Luckily the tornadoes didn't hit any towns (though one of the tornadoes formed just 1 mile east of Scottsbluff, population 14,732-YIKES! :shock: ) and there was some considerable damage to some farms south/southeast of Scottsbluff in Banner County east of Harrisburg and southwest of Bridgeport, which thank goodness is a very sparsely populated area, but no one was injured so that is great news.
There was also a very large tornado that passed just a few miles north of the small towns of Dalton and Potter, which are along I-80 between Sidney and Kimball. It could have been very bad if that particular storm had steamrolled through those towns, because they are very small (both have populations less than 500) and according to the local storm report that twister was a half mile wide and was probably at least an F3 if not higher, but fortunatley Lady Luck was smiling on the Nebraska Panhandle last night . If you feel inclined to share any thoughts/comments/musings on this storm please post them. Thanx!

 

[joel ewing]

As a longtime chaser and originally being from s.e. Nebraska myself....I've said it a zillion times to my chase partners....."It's Nebraska...and it's JUNE. Chase it!!
Thanks for your posting on this event. Too bad you just missed out. It was a valiant effort, for sure! Joel Ewing

 

[Jim Tang]

Yep, I must agree, that supercell was a MONSTER.

Anyway, a few hours before, I briefly glanced at SPC Meso Analysis (yeah, I know it can be misleading, but my forecast skills are awful). Before the event, the Supercell Composite Parameter was relatively high, and the Yellow Box that went out for WY, west SD, and the NE panhandle highlighted this. However, LCL's were extremely high as well.

This leads me to the conclusion that many of the reports are false reports of low hanging scud, weak landspouts, or RFD gustnadoes. However, a few of the tornado reports could be true (especially the half-mile wide one). After all, this supercell moved overall to the right of the mean wind, enhancing SRH, and any lone boundary could have enhanced tornado potential.

 

[Kyle Masters]

Originally posted by joel ewing
As a longtime chaser and originally being from s.e. Nebraska myself....I've said it a zillion times to my chase partners.....\"It's Nebraska...and it's JUNE. Chase it!!
Thanks for your posting on this event. Too bad you just missed out. It was a valiant effort, for sure! Joel Ewing

Same goes for South Dakota...the addage here is "This is South Dakota. Don't like the weather? Wait til tomorrow."

 

[Mike Peregrine]

I'm also glad that someone posted on this and hopefully we'll solicit some ideas concerning the formation of this beast. It looked incredible on radar, every bit as incredible as the Trego Co. storm did a couple weeks back. I was wondering if there may have been some local boundary at work that may have worked to enhance this storm's ability to produce tornadoes. As far as I can recall, it really wasn't on anyone's forecast radar screens in advance (though I'm sure we'll hear about all the folks who were forecasting it and just never posted - ha - j/k). Looks like Dean Cosgrove intercepted it (naturally), so at least one chaser was on the lookout.

 

[joel ewing]

Ahhhh, Jim......man I dunno. From the looks of that storm on radar and on satellite.....I'd bet those were full-fledged meso tornadoes all the way...and big ones to boot.
It'll be interesting to see if Dean was on that storm, and if he'll peek into this forum and weigh in. If he was at home somewhere down around Frontier county, I think he's in....he'd be just a hop and a skip away from there.
Just goes to show you....Mother Nature is still the commanding officer here.

 

[Tony Laubach]

Like Mark, Verne Carlson and I made a made dash from Denver to intercept it very late in its life cycle. We ventured over 150 miles to intercept and rounded out over 400 for the trip. We were hoping to catch one last tornado before dark, but obviously weren't lucky enough to get one more out of it.

I began watching this thing when I turned on my laptop and went to NWS homepage and saw the red boxes (counties) in the NE Panhandle. I looked at the radar and said... "$h*t!" Yes, I actually said "$h*t!". Bouncing phone calls between Verne and Jon V, we killed off an hour before Verne and I decided to race along I-76 to try and intercept it in Sterling. We ended up in Amherst before we started seeing any precip and stopped half a mile inside Nebraska when we realized the storm was either weakening or hauling balls east.

This was an odd storm that unless you lived (or were stationed) close by the storm at the start and saw it go up in person or on radar, you probably never thought about chasing it til after its second hour of existance. Obviously the further ou you were, the more you probably thought this would weaken long before you made it. Obviously that wasn't really the case as it lasted several hours before kicking off.

I'm curious to see the parameters in this area prior to the storm's birth AND during the storm's life cycle. I will mention that I saw no boundries of note near the storm when I started watching it on radar, so my only guess would be a dryline relation. Again, I don't know where and how the dryline was set up in that area or how it was interacting with the surrounding area, but I'm sure that had something significant to do with this storm's evolution.

Verne and I discussed this on the way home and thought about a southward moving boundry (quasi-stationary front) that kicked up the storm and pushed it southward along the dryline til dark when the boundry either stopped moving south or it simply weakened due to lack of daylight. That's our synopsis just from quick observation, but are curious as to the setup that lead to this beast.

Its a shame the area didn't really hold any alerts to get someone up there during its entire lifecycle, but kudos to those who ran it down anyway!

 

[Mark Farnik]

I'm glad this topic is of some interest to everyone. Jim, I am subscribed to Accuweather Premium and the Storm Information Table had a TVS label on it for almost three hours straight. I took pictures of the cell throughout it's lifecycle from the southwest and it had an extremely well defined updraft and overshooting top. I was looking at yesterday's weathermaps and have come to a similar conclusion as Tony has; a weak quasi-stationary boundary was the likely catalyst for this cell. It had quite a lengthy lifespan, and was severe from just before 4 p.m. to 9:30 p.m.
It didn't last long after dark because it was completely solar fed; once the heating of the day was gone, it weakened fairly rapidly due to the lack of a LLJ or any outflow boundaries from other storms to feed on. If this had been a more classic setup, the LLJ and/or the outflow boundaries would likely have kept that beast tornadic one or two more hours and severe well into the early morning hours. Of course, if it had, it might have wiped out one of the countless small towns that dot eastern Logan, southwestern Sedgwick and Phillips counties. So it was a blessing and a curse. You don't want to see an awesome, violent long lived tornado in exchange for one or more small towns or multiple farmsteads being completley wiped out and countless lives changed forever or, as the case somtimes is with violent tornadoes(especially at night) ended.
Speaking of outflow, the outflow from this storm was ridicoulous. We were driving into a 30 to 40 mph headwind from Stoneham all the way to Holyoke. And according to Dean the inflow was even stronger. Well gentleman, carry on. You all seem to enjoy tossing ideas on the why and weather of this beast around, as do I. Now, if only we could find out if some yokel local got some pics of these twisters... Those would be sweet to see, for sure. 8)

 

[Jim Tang]

Well, I guess you're all right. You've convinced me. These were likely legit, mesocyclone tornadoes that happened in an environment that many thought was too marginal for tornadoes. To tell you the truth, I was watching radar all throughout the lifespan of the supercell. Yes, it had a spectacular presentation on both radar and satellite. The only reason I doubted these tornadoes was that LCLs were extremely high, and reflectivity can be deceiving.

Well, I'm still a newbie. Lots still to learn, and heck, it was unforeseen by professional forecasters. Somewhat like the June 5 2005 event (Borden County/Howard County cyclic tornadic supercell) where there was only a Severe Thunderstorm watch in effect. And the April 20, 2004 Utica IL tornado occurred on a day where most were focused down in Oklahoma. Mama nature can still surprise the best of us!

P.S. Just some trivia for you - this supercell had more tornado reports than the June 12 Jayton TX supercell. Oh and BTW, both supercells produced most of their tornadoes in a two-hour period. AND June 12 was a MOD!!! This (for most of the day) wasn't even a SLGT. :shock:

 

[Joe Zemek]

I totally missed out on chairchasing this storm, but I think that high LCLs at higher altitudes are more easily overcome by 850 juice. The June 2 CO storms formed in an area of weak to avg. SFC shear and T/Tds of around 80/57, but at 850 Td was around 16C and winds were SE around 20kts. I'd guess this storm may have benefited from a similar scenario, and with better directional SFC shear.

 

[Mike Hollingshead]

That storm was in a lovely environment for supercells...obviously. Someone can look up the exact details but when I glanced 850 was se at like 15-20 knots with 500 wsw at 30-35 knots(guessing on what I think I remember). To me that is perfect turning with height as it isn't too close to 180 degrees and there is plenty of turning. Those number may have been even less than that. Up at 300mb I think they were around 50 knots. Don't recall too much about the sfc boundary but it was evidently laid out well(n-s). It takes quite a bit to get such a nice supercell like that. It really never is a fluke. I'm half tempted to quit chasing anything with less than 120 degrees between the sfc and 500mb......and chasing everything I can with it(and bust anyway like today).