8/19/05: NOW - Central Plains

[Jayson Prentice]

Some warnings are up along a nearly stationary boundary that is through KS/MO. Watching the cold front move southeastward through Iowa now, looks like some development starting along the front. An outflow boundry also looks like it is located from about Seward to Tekamah, NE. This boundry looks like it is begining to show some small development along it.

Ben L. and I are in Denison, IA right now. We are hoping for one of the "one or two tornadoes" that DMX/FSD are talking about. Conditions are better further north, but with the cold front only push they will likely be linear quick. Hoping for some of the outflows from the crapfest in NE can increase some convergence/shear and touch off something.

 

[Tim Stoecklein]

Doppler indicated rotation in addition to spotter reports bring the tornado warning in Rush Co., KS. We've seen initiation here in NE KS as well. Towers continue to go up, but our winds are much more unidirectional compared to those WSW along the boundary. Will see what the heating of the day brings as things have cleared out considerably.

Tim

 

[Kevin Scharfenberg]

Now a "tornado emergency" for a tornado over/near Great Bend, KS. The front there doesn't look strong enough to undercut a circulation, so there might be a "sweet spot" with enhanced near-ground helicity along the boundary. Deep layer instability and shear are certainly favorable enough for supercells. The radar presentation certainly shows a supercell, but the lowest cut is unusual with an initially detached small cell riding northeast along the southeast flank of the big main cell and attaching itself, with a strong velocity couplet all the way. Will be interesting to see if this tornado lasts long.

 

[nickgrillo]

Now a "tornado emergency" for a tornado over/near Great Bend, KS. The front there doesn't look strong enough to undercut a circulation, so there might be a "sweet spot" with enhanced near-ground helicity along the boundary. Deep layer instability and shear are certainly favorable enough for supercells. The radar presentation certainly shows a supercell, but the lowest cut is unusual with an initially detached small cell riding northeast along the southeast flank of the big main cell and attaching itself, with a strong velocity couplet all the way. Will be interesting to see if this tornado lasts long.

Rotation appears to be pretty strong on radar, and it's been able to maintain low-level rotation for a while now. Overall flow in this small region in pretty strong at all levels... The directional shear is pretty good, so I'm not surprised to see decent low-level rotation and tornadoes from time-to-time. With 35-50kts deep-layer shear and 3500-4500 CAPE, I'd expect this supercell to remain strong for a while. Mesoanalysis showing >250 SRH near the supercell, and this thing is pretty isolated and established, and is rooted right on the boundary.

 

[Jeff Snyder]

I was thinking that SPC was going to go with a tornado watch given the favorable orientation of the front in Kansas. Given the ENE-WSW orientation, given storm motions certainly supported the possibility of a storm or two "riding" along the front. It's always a good sight to see 88/72 with northeast surface winds as was the case right along that front earlier this afternoon. Strong deep-layer shear, moderate-strong instability, and very favorable low-level (including 0-1km) directional shear suggests a pretty good tornado threat with any supercell that can remain near the boundary. I wish I would have acted on this earlier this afternoon, when I may have had time to get up there.

I see the new MCD from SPC highlighting an enhanced tornado threat invof the boundary.