8/17/05 NOW: Central Plains

1km visible loop and local generated short-fuse composite indicate that convective initiation may occur in the next couple hours in south-central KS near Pratt. The short-fuse composite "threat area" is focusing on Pratt, KS on the 19z analysis... it'll be interesting to see what happens. Deep layer shear is marginal for supercells, but > 3000 J/kg CAPE should make thing interesting...

Mike U
 
The thread title should be changed to include the rest of the central plains...

Dryline/sfc trof continues to push east through NE/KS, with CAPEs now >2000J/KG across most of the region - with good moisture pooling at the SFC. A strong short wave approaching will enhance convective possibilities later this afternoon, and with pretty decent surface flow, deep-layer shear is >40kts across most of the area... Given the favorable airmass in place, supercells should fire within the next couple of hours in KS/NE -- with the biggest threat being very large hail, although a couple tornadoes are likely IMO.
 
I Agree Mike. I have been watching SC KS closely throughout the day. A nice cu field has been developing since noon and the mid level clouds have dissipated over the past few hours over this area. The 18Z RUC run nailed the pricip/tower developing over the north TX panhandle and it continued to show pricip over SC KS. If I could go, I'd pick the Pratt area as well because that’s not real far form the initiation points.

Mick
 
Nice to see some consensus on Pratt. Gabe Garfield and I are sitting at the Days Inn here in Pratt right now. Radar showing a couple cells trying to break free (one to the southeast and one to the immediate west-northwest). The congestus is quite clustered... looks pretty good. Deeplayer shear not as much asI had anticipated (12z NAM had 40kts here by 0z), thanks to poor mid-level flow. CAPE and low-level shear isn't too shabby per SPC mesoanalysis (3000+ CAPE and 150m2/s2 0-1km SRH). We were thinking of going further north earlier today, but this looks as good as any place south of the KS/NE border -- so here we stay.

EDIT: HVL profiler showing that RUC is underanalyzing low-level flow... The profiler is showing 30-35kts between 700-800mb. Yay! LOL
 
The radar of NE KS looks amazing - sadly enough, this is the first hook echo I've seen so far this season.

The SPC has even put out an MD solely on that cell citing that it will be a long track supercell. A brief tornado could not be ruled out. It has already produced .88" hail and 70 mph winds!

I wish you all the luck guys - be safe.
 
Take a look at that isolated supercell in northeast KS, which has been tracking along the NE/KS border all afternoon. Although it's intensity has been cycling a bit, it still maintains supercell chararistics - and given >2000J/KG of CAPE in that region, a large hail threat with it should continue. Too bad low-level flow is so weak, as I'd definitely see a tornado or two coming out of that...
 
Starting to see some pretty good Gate to Gate on the velocities...Right now it's -27.5/+7.5 (i don't know the proper way to read that :oops: ) near Vermillion/Centralia.

Plus a shear marker (3DC) just popped up on the 88D!

I'm looking for a torn warning in the next few minutes...
 
Pratt area could work out - but there appears to be an awful lot of development also trying to get going to the southeast of that area - which could intercept much of the what little 850 flow there is. That said - vis sat does suggest at least some seperation between that area and the cluster/line to the northwest of that region. Radar animation shows winds at/near the sfc around Pratt are from around 190 - so I'd probably track a bit northeast from there - and hope an interesting cell emerges out of the cluster in Edwards county - maybe head up to around Sylvia.

Good luck.

Glen
 
Holy crap there is some nice hooking going on on that cell...Tilt's 1 and 2 show a developing hook around where the velocities show +27.5/-47.5, and the 3 and 4 are wrapped around that area. There is also the white blob coming down the tilts that i read somewhere is a theory that it's a sign of tornadogenesis.
 
We're on the Stafford county cell currently, there is quite a bit of storm base rotation. However, nothing looks too organized yet. It does look weakly supercellular. Looks like the precip is undercutting the updraft right now...hoping for deviant storm motion.

EDIT: 5:20pm -- Clear RFD occlussion with pretty good wallcloud structure for a little while. Looks liie precip is still undercutting the updraft, however. Looks like a minor right-turn may have occurred recently.
 
We're on the Stafford county cell currently, there is quite a bit of storm base rotation. However, nothing looks too organized yet. It does look weakly supercellular. Looks like the precip is undercutting the updraft right now...hoping for deviant storm motion.

EDIT: 5:20pm -- Clear RFD occlussion with pretty good wallcloud structure for a little while. Looks liie precip is still undercutting the updraft, however. Looks like a minor right-turn may have occurred recently.

Been watching this on WDSSII up at the lab...seems to be going through a cycle...when Jeff reported best base rotation, corresponded pretty well to an apparent (and very weak) meso on the storm. Last couple of scans show rotation has dissappeared and base reflectivities up slightly...maybe it can get another good updraft going...if not, wouldn't be surprised to see it disappate.
 
Still on the Pratt Co. storm...about 5 W of Preston, KS currently. Have seen several impressive wall clouds, but little in the way of consolidated rotation (with the exception of one or two attempts). RFDs have been slightly on the wet side, and no visible clear-slots have developed as of yet. Even so, weak rotation continues at cloud base.
 
thank you for these reports Jeff... you are indeed helping in the decision making here :) 0.5 velocity looks quite poor which matches your observations... nice supercell!

Mike U
 
Currently west of Kingman, pretty much calling the chase off. The supercell had very nice structure for quite some time, especially in the past hour or so. However, it looks like garbage now, so we're just going to ride it east to I35. There were numerous RFD occlussions, though most were wet (precip-filled) and not very warm. Some VERY intense winds associated with the RFD to the southeast of Preston, along with several gustnadoes. There was a very brief spin-up that Gabe and I deliberated about for several minutes. In the end, we called it a tornado given it's position underneath the wall-cloud, and it's intense rotation (much more intense than the gustnadoes we had seen). It wasn't a "good" tornado, so those who missed it didn't miss much, as it only lasted 5-10 seconds. At any rate, we're currently in some VERY intense rainfall and about to get stuck on these CRAPPY southwest Kansas dirt roads (ooooh do I have stories...). Lots of wall-clouds, lots of RFD action, very nice structure, and boooo for tornadoes.
 
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