4/25/08 FCST: IL/IA/WI/MO/AR/OK/TX

[Andrew Pritchard]

Iowa certainly is clearing out, but I wonder if there isn't a good amount of subsidence there at the moment and that's the reason it's completely clear. It's certainly destabilizing, but we'll have to see if convection is able to get going ahead of the cold front.

I'm keeping an eye on that area, but my main target is still western Illinois from Jacksonville to St. Louis. There is a lot of deep moisture convergence along the boundary left from the morning mcs in that area and it may kick off a few discrete storms. Unfortunately the strongest LLJ is just to the north of this area. However, the RUC still keeps winds SSE in this area increasing helicity values.

I'll probably wait around until the noon hour data filters in and eat some lunch and begin drifting west and adjust north or south depending on which target begins to go.

Weberpal - - - I'm guessing if you catch a beautiful Wisconsin tornado I'll be the first to get it thrown in my face for knocking the north.

 

[Brent A. Clair]

W IL is not bad, but the way that front is moving, I wonder if any storms will be able to develop fully before reaching the area. Nice environment overhead, but needs about another hour to "season the skillet."
On the bright side, a nice day outside. Then it has to go and get cold again this weekend.

 

[nickgrillo]

I'd bet on northeast IA / southwest WI for the best tornado potential -- right along / near the boundary, where boundary layer flow is backed and low-level (0-1km AGL) SRH (> 250 m2/s2 per RUC mesoanalysis) is increased. Insolation has allowed for strong diabatic destabilization with RUC/SPC mesoanalysis showing 1000-2000j/kg of SBCAPE from southwest WI into northeast MO. CINH is slowly decreasing -- along with lowering LFC heights (soon likely lowering enough to permit low-level ascent) due to moistening / deepening of the boundary layer. Overall, the deep-layer kinematic and thermodynamic structure of mucht of the warm sector is extremely favorable for organized and sustained DMC, with the possibility of a few strong supercells given the favorable shear / thermodynamic profiles from southwest WI into southeast IA. I'd guess convection would congeal into a large-scale convective band and move across IL / IN and into southern MI as the surface cyclone deepens and moves northeast into northern WI later tonight.

Northeast IA and southwest WI seems to have the best shot at a sustained, cyclic supercell and the threat of a strong tornado or two.

 

[Joel Wright]

Current convection is developing right along the cold front. Makes me worry about cold air trying to undercut the storms as it plows east this afternoon. Out ahead of the line, there's lots of cumulus, and even better instability. I'm hoping something can fire out ahead of the line. Surface winds are very slowly veering, but directional shear is still pretty good at this point.

If one of the cells along the line can remain discrete and not get undercut, or something can fire out ahead of line then there's a good chance for tornadoes. Certainly enough risk to probably warrant a watch.

Even if I didn't have an interview at 3:30, I'd still probably be sitting here trying to figure out where to go. Still a bit early I guess. Basically anywhere around the Quad Cities is a decent place to be in right now. Well ahead of the developing line, and instability is highest very near there. (Winds here at my house right now are due south and gusting to near 40mph!)

Good luck to everyone who hits the highway today!

 

[Brandon Sullivan]

Hmm.. Trying to decide where to go.. Tossing between Galesburg, IL and Peoria, IL.. Will likely head to Galesburg... Based on the latest MSAS, some slightly better parameters developing that a way... I will wait for the 20z outlook first..

Edit: 20z Out with 10% tornado placed in Northern IL.. Will be headed out shortly... Going to GBG and maybe further NE if time permits.