2011-04-19 FCST: MO/OK/IL/IN/AR

[Mike Johnston]

Yeah, it looks like fairly early initiation is imminent right along the cold front. SPC has a mesoscale dicussion out now on this point. You can see a well defined cu line developing right along the cold front and there's an incipient cell developing on radar north of Carthage in far SW MO. Whether anything actually initiates this early further east along the warm front is questionable, but CIN looks to be eroding across a portion of south central MO.

 

[James Langford]

If the latest run of the HRRR verifies, we could be looking at some large supercells developing just west and north of the DFW area. Most likely will be fairly elevated with large hail and high winds. Definitely keeping an eye on things here.

 

[Rob Gardner]

Original plan was Vandalia, IL, I instead chose to come down 55 and head towards Jerseyville, IL North East of St. Louis. Based on the latest RUC, looks like the cap is already starting to erode, and we could expect a super cell or 2 to initiate west of the mississippi and track east and just north of St. Louis by 22z. Unfortunately there aren`t any east west routes that are really manageable so looks like the best bet is to get as close to the river as possible and prepare to intercept. Depending on how storms initiate, I think it is possible there could be a few supercells that train before they veer more to the north as time progresses.

 

[John Farley]

I agree with the Jerseyville target, or perhaps a little east of there. Warm front has surged north, bringing clearing and dramatic warming to the STL area. Surface winds southeast, so good low-level directional shear. Already have CAPE at 4500, EHI at 6, and Sig Tor at 5 just southwest of STL, per SPC mesoanalysis. With continued heating, these indices will likely go even higher. I think there will be discrete supercells for a while along the WF, while things will line out more quickly along the CF. Note the derecho index is off the roof along the CF, but not along the WF, though eventually would not be surprised to see one there, too, but later and farther east.

 

[Mike Smith]

3:10pm CDT: The cells developing near Eldon MO (NE of Lake of the Ozarks) seem to have "St. Louis" written on them. Agree with John above. I don't like the way things look for St. Louis Bi-State area for late afternoon.