6/21/07 NOW: NE SD KS IA MN MO

[MatthewCarman]

"...GIVEN MODERATE INSTABILITY AND STRONG DEEP LAYER SHEAR OVER SRN SD/NRN NEB...POTENTIAL WILL EXIST FOR ADDITIONAL TSTM DEVELOPMENT AND ATTENDANT SEVERE THREAT..." (SPC MD 1238)

I'm not chasing today. Although there 'is no cap being reported' in IA, the tornado threat will be decreasing as the discrete cells congeal into an MCS.

The tornado threat was only 5% chance to begin with which is not very good so I would not expect many tornadoes today. I did read that but I just dont see much more than some hail or damaging winds in NE. The SPC has added NE into the slight risk though.

Looks like severe storms continue in northern IA and a strong cell now in west central IA near Dennison.

 

[Chad Cowan]

The tornado threat was only 5% chance to begin with which is not very good so I would not expect many tornadoes today. I did read that but I just dont see much more than some hail or damaging winds in NE.

Do you have any data to back that up? Or is that just a guess? The effective bulk shear in extreme NC NE and SC SD is over 50 knots... the 0-3km SRH in this area is ~300 m2/s2, which are both more than sufficient for tornadoes.

 

[MatthewCarman]

Do you have any data to back that up? Or is that just a guess? The effective bulk shear in extreme NC NE and SC SD is over 50 knots... the 0-3km SRH in this area is ~300 m2/s2, which are both more than sufficient for tornadoes.

Well the SPC has only a 5% chance of a tornado for your area but if you do get a tornadic strorm in NE mabey you will get to chase after all.

A storm north of Fort Dodge IA is now capable of producing a tornado. IA may see it's first tornado of the day.

 

[MatthewCarman]

Currently 3 storms Tornado warned in IA and another in south central MN.

Those storms around Allison,Waverly and Waterloo Iowa is inpressive. GRLevel3 showing hail 1-2" in diameter and rotation with these storms. Winds in excess of 60 MPH also look possible with these storms. Another strong line of storms now west of Des Moines that could form into a nice bow echo. Destructive winds in excess of 80 MPH are possible with these storms. Looks like

IA is realy lighting up with severe weather. Is anyone seeing any tornadoes yet with those tornadic storms near waterloo?

EDIT: Radar is indicating a nearly stationary tornado near the waterloo airport. This is what the NWS has in thier wording for the tornadic storm.

 

[MatthewCarman]

A tornado warning now for Story County IA just north of Des Moines. Radar is detecting a storm capable of producing a tornado near ames.

 

[MatthewCarman]

Trained weather spotters are reporting a tornado near Ames airport moving east towards Nevada at 30 MPH.

 

[Jim Tang]

In all honesty, the cells in IA look like junk to me. I don't see a report of a tornado w/ the Ames cell.

The best place to be right now, IMO, is in western SD. Upslope along the Black Hills has not dissapointed (in terms of just simply providing severe) this year, and today has not broken the trend.

 

[Dick McGowan]

In all honesty, the cells in IA look like junk to me. I don't see a report of a tornado w/ the Ames cell.

Yeah, I don't see a tornado coming out of this cell. Maybe a gustnado? You can clearly see an outflow boundary being pushed out ahead of it now. Tornadic threat for IA seems pretty low now.

 

[Mike Hollingshead]

The only decent one I've noticed was that one in southern MN. It's been rather deviant. Which is toast now that it is encountering the crap air to the south.

 

[Dustin Wilcox]

Wish I wouldn't have displaced myself to far from being able to get back West, as C NE looks decent. Storms have developed just North of North Platte and will continue to move into a enviorment favorable for supercells excluding marginally high LCL's. High res satellite indicates aggitated CU field that looks like it could fire anytime in SCNTRL Cherry CO as well, will be interesting to watch this evolve. If storms can propegate E a couple of counties they will encounter decent 500mb 850mb crossovers that should only continue to improve through the evening.

 

[MatthewCarman]

Trained weather spotters reported a tornado in story county Iowa. It is to early to see a report with this isint it?

New tornado warning Madison and Warren counties. A tornado is being reported moving east of Winterset at 30 MPH.

 

[Chad Cowan]

Yeah, I don't see a tornado coming out of this cell. Maybe a gustnado? You can clearly see an outflow boundary being pushed out ahead of it now. Tornadic threat for IA seems pretty low now.

I would definitely say that was a gustnado reported. The warning message said that it was reported @ 4:59 near the Ames airport, and at that time, according to GRL3, the OFB was directly over Ames.

 

[Brandon Lawson]

Is anyone chasing in SD right now? A lone storm has popped up and is just south of Dupree. It looks jolly good.

 

[Chad Cowan]

Is anyone chasing in SD right now? A lone storm has popped up and is just south of Dupree. It looks jolly good.

It looks like Laura Heiden is going after that cell. It has consistently had a meso marker on it, but it seems that most of the rotation has been at the mid-levels.

Further South... the cap over NC NE has weakened considerably, and the SRH has been constantly increasing. Given the moderate instability and the developing Cu field, it would seem that development north of the SVR warned storm in Thomas Co is imminent.

 

[Dick McGowan]

That Ziebach, SD cell kind of started out moving S/SE and has since been moving S/SW with that outflow boundary. It will be interesting to see what it does in the next few scans.