Tornado event Friday from Illinois to Western Ohio?

[Dan Hildebrand]

There looks to be a chance of Tornadoes towards Friday. A Cold Core Low is forecast to track Eastward into Ohio. A setup of this sort is responsible for the April 10, 2005 tornado outbreak in Kansas. Attached are graphics by the local weatherman. What do you all think of this?

This was as of last night, so i'm not sure how the forecasted track has changed

 

[Wes Carter]

There is going to be a trough ejecting from the Rockies tomorrow. The NAM and the GFS both show 65-70 degree dewpoints nosing up into Kentucky. However, both models are showing the instability axis staying further southwest into western Tennessee, northern Mississippi and norther Alabama. It looks like there is going to be a nice low level jet bringing moisture up from the gulf to fuel the storms. And the forecast hodographs have a real nice wide sweeping curve to the right. It doesn't look to me like the LLJ will be running parallel to the trough, so I'm guessing that it won't develop into a line as it stands now. I'm going to pay attention to this one for sure, especially since it is close to home and I don't have to work. But there could be some tornadoes in MS, AL, and TN.

I noticed your graphic is from April 10. Even now this event is a day 3 event, so a lot can change. If that trough doesn't stay negatively tilted it could run parallel to the LLJ and just produce a squall line. But maybe one heck of a squall line.

 

[Dan Hildebrand]

Thanks for your input!

But also notice that April 10th graphic is from April 10, 2005, which shows the setup that produced tornadoes in Kansas on that date

 

[Wes Carter]

LOL, the year *IS* important!!! But I don't think there is enough information on that TV weather chart to make any kind of meaningful correlation. And I'm not well versed on cold core setups, maybe some of the others who seem to score a few of those like Verne Carlson, Skip Talbot, and others will chime in.

 

[Skip Talbot]

For comparison and good reference see: http://www.jondavies.net/041005nwks/041005nwks.htm

The 12z NAM is plotting a cold-core type surface pattern over northern Missouri in the early afternoon on Friday:

http://www.twisterdata.com/data/mod..._221_2011041312_F54_DPTF_2_M_ABOVE_GROUND.png
http://www.twisterdata.com/data/mod.../13/12/NAM_221_2011041312_F54_TMPC_500_MB.png

I'd circle the maps if I had the time, but the area we're looking at is the 50's dews that are sitting right under that 500 mb low. The better dews to the southeast are really part of a more conventional warm sector setup.

It's probably shifted some since the above graphics were made. The problem I see here though is that cold core setups often rely on strong solar heating, which results in steep low level lapse rates. However, the NAM is showing the area socked in with rain and precip:
http://www.twisterdata.com/data/mod...13/12/NAM_221_2011041312_F54_CREF_SURFACE.png

If that's the case, the area will not destabilize, and we'll just see some showers over northern MO. What we could really use is a 700 mb dry punch to clean out the clouds and get some sun to destabilize the cold core target:
http://www.twisterdata.com/data/mod...04/13/12/NAM_221_2011041312_F54_RH_700_MB.png

You can see there's something like a dry punch on that plot, but its well to the south of the cold core (over the warm sector).

I'm not sure this target would pan out based on these plots. I'd probably be eyeing the the southern MS valley for more of a chase target, the same region SPC highlighted. You'll want to monitor how these parameters actually evolve, however, as cold core setups come and go quite quickly on the numerical models, so it might more of a day of the event type thing to pick up on.

 

[Jeff Duda]

Dan, I would suggest starting a FCST thread for this event. Great meteorological discussion is had there. That's the place to go if you really want to learn about how these events go from a forecasting standpoint and a chasing standpoint.

 

[Matt Hunt]

I'll be watching this one closely as well, since it might setup close to home. Though judging from that link Skip provided, it looks like the best spot would be further to my west, and since I won't be out of class until 4 or 5, I may not have enough time to get there. So I'd like to see things shift to the east a bit. It is still a few days out, and I'm sure things will change, so probably wait to do the best analysis of it until Friday morning.