06/25/10 NOW: IA/MN/NE/SD

[Jeff Duda]

Decent CU field now appearing on visible satellite in SE SD. The sudden appearance of it suggests either some UVV in the area or convective temp (below the cap that remains) has been reached locally.

The environment in the four-state area looks pretty good minus the CIN still present. Up to 65 kts of effective deep layer shear exists over SW MN with > 45 kts covering all of SW MN and parts of SE SD and NW IA. Up to 20 kts of 0-1 km bulk shear is present across much of MN, as well. With decent 20-30 kts of Sly flow at 925 mb and ~30 kts of SWly flow at 850 mb, this is allowing for 0-3 km SRH of up to 350 m2/s2 and > 150 m2/s2 0-1 km SRH in the area. A tongue of instability with SBCAPE up to 5000 J/kg is providing for a very unstable environment. Lastly, low level convergence near/east of Brookings, SD is providing for some good lift in the area. As soon as this lift and instability slide out under the cap (like the edge area where H7 temps are 12-13 C over the SD-MN border), and with a little more surface heating, initiation should explosively take place.

I'm kind of surprised to not see any MD's or watches yet out for the area.

 

[Jeff Duda]

MD's are out for the area

Just issued at 2:44 PM I see.

Looks like they're saying some of the same stuff I did. I missed the surface cyclone. You can see it on satellite, but it is difficult to see from just surface obs.

 

[Jeff Duda]

Looks like something may be getting going. A small cluster of updrafts appears to be congealing in Lac qui Parle County, MN. It appeared to develop along the front edge of the Cu field that intersects the warm front. It was initially moving northeast, but has since turned easterly, probably becoming surface based and anchored to the boundary. FWIW, the 17Z and 18Z HRRRs had a storm developing very nearby where one is currently located, only about one county too far south.

 

[Jeff Duda]

Here's a new one from the NWS:

* AT 459 PM CDT...RADAR INDICATED A CLUSTER OF STORMS CAPABLE OF
PRODUCING TORNADOES.

I've never heard of warnings issued for a cluster of storms each capable of producing a tornado.

 

[ahaberlie]

They look pretty much like supercells on radar and the velocity data is showing a strong couplet near Sleepy Eye, MN.. could also be some mesovortices on the leading edge of the precip.

*edit

Funnel reported a few miles NW of Sleepy Eye, MN or 6 miles SW of fairfax, MN.. pretty close eh?

 

[Dave Gore]

Steve Miller (TX) is streaming a beautiful landspout tornado southwest of Thedford, NE. This thing is almost stationary, moving south at 5mph.

http://www.chasertv.com/api/static_pages/lite/167_steve-miller-tx.php

 

[MatthewCarman]

That storm east of Slayton, Minnesota heading towards Windom is showing tops in the 70 thousund foot range according to GRLevel3. It is not often you see a storm with tops that high.

 

[Fred Dearborn]

That cell is massive,and getting reports of a tornado on the ground.Hope eveyone is taking cover.

 

[jshields]

Steve Miller (TX) is streaming a beautiful landspout tornado southwest of Thedford, NE. This thing is almost stationary, moving south at 5mph.

http://www.chasertv.com/api/static_pages/lite/167_steve-miller-tx.php

still has one on the live feed!!

meanwhile the tornado warned storms in minnesota are beginning to move into the areas that were hit so hard on june 17th. hail markers are consistently showing 3.5"-4" hail too!! seen lots of reports of rain wrapped tornadoes too, so it is dangerous out there!

 

[Jayson Prentice]

Impressive velocity couplet on the storm near Sibley, IA... Tornado warning was issued with funnel cloud and tornado reports soon to follow. Saw a couplet with GTG shear of 140 kts at just 3300 feet just to the west of Sibley as the tornado was reported on the ground. Looks like it is loosing some of its' velocity now, but will have to watch the western edge of the line as it continues to back-build as it may pose a tornado threat once again.

Also, as the line of storms moved into northern Iowa have seen several reports of winds 60-70 mph with power lines and trees down. Both my parents and in-laws have lost power as a result of the winds.

 

[Jeff Snyder]

Andy Gabrielson is streaming a nice cone tornado S of Sheldon, IA, at http://www.severestudios.com/cgi-bin/player.pl?username=andy.gabrielson&uid=140

It's interesting to see how quickly the very tight couplets develop as new convection develops along the western edge of the line. I've been trying to do "print screen" captures when the lightning illuminates the tornado, but I haven't had any luck yet. It looks like it's been obscured by rain now.

It looks like Andy has turned around now, so I'm not sure if we'll see it again. Latest TVS has maxdv of 123 kts.

 

[Jeff Duda]

The entire set of activity (squall line and tail end charlie supercell) are about to move into an area with 700 mb temps of > 14 C. Interesting to see if the storms survive much into that area.

 

[Jayson Prentice]

What may also be interesting to watch is how long and how far west the 'tail-end' of the line can make it and remain tornado warned. As it re-develops back to the west it will continue to engulf even more unstable air and will remain along the 12C isotherm at 700hPa. It may very well make it to the Missouri River before the shear begins to become unfavorable and we finally start to lose enough instability.

 

[Jayson Prentice]

The next tornadic circulation has developed to the east of Granville, IA... At the same time the next updraft for the back-building line of storms is occurring just east of Orange City. The line looks to continue to produce tornadoes...

 

[Rean Clover]

Where are your folks from Jayson? I live SW of Sibley by Ashton, power was lost there. Little Rock had a confirmed tornado with small buildings destroyed, power lines down, and trees. I don't know how our house fared, as there was a tornado near there, and I am at work in Sheldon. However when all that was going on, there was a huge meso-cyclone right on top of us. Very impressive.