6/18/09: NOW IA

[Andrew Stoller]

Well, the cap has finally broken in ne IA. Explosive supercell now with a hook and a TVS. Likely a very dangerous night for people in the upper MS valley.

 

[Andy Wehrle]

Good night all,

Only cell I see that is a supercell is NW of Prarie De Chien IA and crossing the river into Crawford County IL (has TVS).

Took all this time for cap to break?

That's Iowa for you guys ;-(

What are we, a big cheesehead-shaped void east of Iowa and north of Illinois?

In all seriousness, very classic supercell in progress just to the north of Prairie du Chien, WI with a pronounced couplet. It's been turning gradually to the right since it initiated.

 

[David Draun]

Too bad IL is capped. The RUC mesoanalysis suggests an effective inflow layer significant tornado parameter of 11!! in Lee country, IL. Any storm that could form in that area would go bonkers in a hurry.

But ya gotta wonder: with all this untapped instability to the south, tomorrow could be a good day?

 

[Stuart Robinson]

post Removed by me - Prarie De Chien cell has NOT collasped at all !!!

VIL's have gone right back up in the last scan - Radar pronouced hook now visable.

 

[Andrew Stoller]

It looks like that cell is going to ingest everything around it and turn into a MONSTER here shortly.

 

[Jim Zandonai]

Too late is right.. however strong supercell in SW WI moving east..with good inflow and rotation..looks like WI will be under the gun tonight..too bad this didnt happen in daylight.. ..doesnt look like much south of there still at this hour in IA..or even N.IL.

 

[David Draun]

It looks like that cell is going to ingest everything around it and turn into a MONSTER here shortly.

I dunno, the entire area seems to be filling in with storms. The instability axis is farther south which leads me to believe that cold pools will form and the MCS will begin to surge southward. Any tornado threat would be confined to the south and western parts of this heavy convective mess that has materialized. At least its gotta be a good light show.

Wind threat should get going fairly soon.

 

[Andrew Stoller]

Yea, I agree David. Instability drops off further southeast as well.

 

[Tyler Yarnell]

couplet coming back in a hurry on the cell south of richland center



edit: cell west of Decorah in northeastern Iowa beginning hook echo and couplet is forming


cell south of richland center now tornado warned.

 

[Jacob Ferden]

cell west of Decorah in northeastern Iowa beginning hook echo and couplet is forming

You just beat me to it. Decorah looks to be under the gun shortly. Looking better and better with each run.

 

[John Farley]

Prarie du Chein supercell TOR-warned again in Iowa County (WI). I intercepted this cell between West Union and Decorah, IA just as the storm split and the right-mover became the supercell that produced the earlier TOR warning and this new one. The storm produced an interesting lowering to my northeast as it split, also about the time of the first severe hail report (1 inch) in Calmar, IA. Brief report coming soon.

 

[Tyler Yarnell]

You just beat me to it. Decorah looks to be under the gun shortly. Looking better and better with each run.

yep, looks like a DRC is showing up on the Decorah cell. Other cells in wisconsin is most likely putting down a tornado, very strong, tight rotation. Heading right toward dodgeville, wi

 

[David Draun]

New MD out for current tornado watch. Storms should begin developing southward into IL and a SVR watch will be issued for the overnight hours. Still over 4000 J/kg of instability for this stuff to feed on.

 

[Ben Faber]

Live streams out of Madison:
http://www.wkowtv.com/Global/category.asp?C=164809&nav=menu1362_3
mms://a1864.l922920625.c9229.n.lm.akamaistream.net/D/1864/9229/v0001/reflector:20625

 

[Tyler Yarnell]

Wow last scan has the cell south of Decorah blowing up. Developing hook, very nice couplet. Just east of postville, ia following a similar track of the first tornado warned cell.