4/03/11 FCST: KS/OK/NE/MO/IA/IL

[Skip Talbot]

The CAPE looks good at over 2000 J/Kg and higher towards 00z. However, I'm thinking like Skip. With the cap at almost 3 at 00z means that if it does break, I fear it will be after dark where everything will just weaken from there. Dew points are good, CAPE is good, but the Cap? Not so sure..

Capping should be less of a concern for the northern end of the target area. The NAM continues to open up that cap over much of eastern IA and northwest IL to a gaping hole by 7pm Sunday. Meanwhile the dryline continues to exhibit excessive inhibition. We'll wait and see if the RUC or HRRR have any surprises for us tomorrow morning, but its just looking like elevated hailers down there at this point when the cold front forces something up tomorrow night. My initial target for tomorrow is probably somewhere between Keokuk, IA and Princeton, IL. Storms should initiate under that hole in the cap as the trough starts to eject over the warm sector and the warm front pushes north. We'll be playing a kind of tight rope walk between the better instability to the southwest and the better directional shear that's displaced to the east. There might be a sweet spot in the gradients in between in northern IL, but parameters we'll be fairly modest with Cape somewhere between 1000 and 1500 and 1km helicity between 100-200. We could see a tornado or two if storms stay discrete long enough to mature and progress toward those better backed winds along the warm front. Its an easy play for me coming from Chicago, but quite the gamble for anyone driving any sort of distance.

 

[Matthew Piechota]

Agree completely with Skip and I like target a probably just east of Burlington, IA right now with intentions of staying on the IL side of the river. Going to have to hope for something to occur in the better juxtaposed region of instabilit/low level shear. It will also be interesting to see if any moisture doe mix out and I could see highs busting and creating larger T/Td spreads in the area. It's going to be some very impressive moisture advection nonetheless.

Excited to get out there for the first chase of the season.

 

[Connor McCrorey]

I'm agreeing with Chris on this one. That secondary low developing should back winds to it's E/NE, increasing convergence and hodograph size. In addition, I'm betting the NAM isn't fully resolving the small-scale backing to it's NE, and the additional moisture that should get advected into that little pocket, so instability and LCLs both may be a bit better than expected in that area. Hoping that's enough to break the cap in KS, because that's where I'm going to be!

 

[jeremy wilson]

Hoping that's enough to break the cap in KS, because that's where I'm going to be!

Me too Connor. Winds should wanna back next to this low and with the nicer cape progged to be in this area i'm betting something pops around the 22-00z time frame. My other target was along the warm front in northern missouri around the I-35 corridor. But I'm pretty much sold on the Kansas triple point and better chase terrain.

On a side note I've noticed the 18z nam wants to weaken the cap around SW oklahoma/NW texas. I can see myself sitting in northern Kansas watching a cape bomb explode on the dryline 70 miles from my house while I'm getting a tan. Seems to happen a lot to me...

 

[Donovan Gruner]

One thing I've noticed about the Northern target is the very high RH values near the warm front with very low LCL heights. It seems that there is a possibility that even if storms do develop, which it appears they likely will, tornadogenisis may be hampered due to excessively cold RFD's due to the high relative humidity and low LCL's. The GFS has also significantly dropped the CAPE values of the Northern target to between 750-1500 j/kg, which is still easily enough, but not as beefy as it was in previous runs. I believe that IF storms are able to develop in E Kansas, they will have a much better chance at producing due to better 0-3 km helicity, much higher 0-1 and 0-3 km EHI, and lower RH values. Both targets seem to be a gamble at this point IMO.

 

[Michael Riedl]

The 0z NAM shows a breakable cap anywhere along the Triple Point area and continuing north along the Warm Front.

Initial target of Emporia looks good atm.

Better EHI values are further south but you can get there from Emporia with ease. LCL heights might be an issue further south as well, pros and cons for both but you can work that out tomorrow.

 

[jeremy wilson]

Initial target of Emporia looks good atm.

Myself and Brandon are leaving for a tentative target of Emporia ourselves shortly. Cap continues to be forecast weaker along the triple point and the cape may be better than we've seen all year as with previous setups. i'm just hoping winds can back a bit more in eastern Kansas before the cold front crashes through and all hell breaks loose in the form of a squall line.

i'm also a little concerned with 20 degree spreads around the triple point and sky high bases. We'll just have to wait and see. I'm just ready to see some damn structure at this point. This is the first March in three years I haven't snagged a nader and this year I haven't even caught glimpse of a supercell.

 

[Doug Drace]

Im sure we'll be the lonely chasers Sun here in OK south of I-40, and with good reason, but as I said in an earlier post, I think we'll be hanging around southern/central OK, for a couple of reasons. #1 We work in Ardmore, have to work till 3pm, so even if we busted out of here shortly after 3, we would barely make Kansas by 6:30 with no traffic problems...just not enough time left to enjoy chasing after that. #2 as Jeremy said in a recent post, the NAM has been trying to weaken the cap a bit in S. OK/N. TX by 0z, and the Lift Index is around -7. It will certainly be a task to get a storm to fire on the DL before dark down this way, but I don't believe it will be impossible, and I as well have traveled a few times to a better looking target area, only to have 1 nasty beast fire away from the main event closer to home. So while it's a loooonnnngggg shot, our current target area will be generally just west of I-35 between Pauls Valley and Ardmore, OK. There are still really nice 3km helicity values, deeper moisture and cape in excess of 2500 j/kg. There will be better risks ahead that we can plan better with work schedules in the near future im sure....gfs is already hinting at a potential 2 dayer in the southern plains around next fri/sat....

 

[Matt Hunt]

Anyone else surprised at the difference the RUC is showing? Over 4000 CAPE! Seems odd to me, but I hope it's right! I'm still planning on getting to Quincy and then adjusting from there. Definitely better wind fields in IL, I'm just hoping the storms can get there and stay discrete before sunset.

 

[Tim Jones]

11z RUC is showing impressive CAPE values all the way into SE IA/N IL today. Even if they're overdone, I like the better chances of getting localized backing of the sfc winds east and NE of the low. This may take my target up to Galena to Dodgeville - which is horrible terrain for chasing. The play on the CAPEMAX in No MO may be a good as well, as rapid initiation may stretch the vorticity enough to get a brief tube or two despite the lack of overall directional shear. Kind surprised of the SPC's 10% TOR prob in N MO to be honest.

 

[Jim Parsons]

The RUC is definitely looking better with nice CAPE, EHI and better directional shear....I'm going to head towards the IL, IA & MO border and go from there. In addition to the RUC, Dr. Greg Forbes gives it a 4 on his TORCON scale ;-)

 

[Tim Jones]

EDIT: I like the way the 12z RUC is trending the sfc low and ll shear in IA and N IL today. Another thing I like is the placement of the low in E IA by 23z as opposed to SE MN or NE IA. Despite no initiation by 23z the CIHN values should be reduced enough to allow initiation by 23-0z. My eyes are on comparing the RUC to meso analysis as the day progresses. For now, I'm not heading south' but gonna hang tight in Cedar Rapids and watch things progress. Good luck today everyone!

 

[Tim Jones]

Yeah the KS target does is becoming more interesting with that secondary sfc low and monster cape (for early april). Wishing it wasnt out of reach for me today. I like the way the 12z RUC is trending for down there...

 

[Brent A. Clair]

Being bias to my location since I cannot chase, I still am looking at that little crack in the cap around 22z that might allow some initial convection over the ia/mo/il triple. RUC defn is throwing out some nice parameters. Concern is the next (or first) wave as to if it will reach the Mississippi river early enough to tap into the good stuff. Will target Quincy, IL, because I have no choice!!

 

[Tim Marshall]

TARGET: WICHITA, KS TIME OF DEPARTURE: 10 AM - Strong cold front will roar through KS today and tonight. I am not a fan of chasing cold fronts due to line lifting and storms seeding each other, so I will stay south and play the surface low around Wichita. The dryline appears capped, but I will keep my eye on it. My strategy is to head to Oklahoma City and re-evaluate whether to make the trip up to Wichita. I do have to be at work tomorrow, so I cannot chase past dusk. tm