6/21/06 NOW: WI / MI / IN / IL / IA

I'm wondering if this stuff developing in IA is the activity for later today. The 12Z RUC shows that area of convection nicely as a vorticity maximum on the 500MB map. RUC shows that vort strengthening as it heads eastward into the Great Lakes by 21-00Z, with SBCAPE over 4000j/kg.
 
SPC Mesoanalysis still shows strong capping all over the place. CAPE however is already at 3000 J/kg and it's only 9:30 AM! Ongoing convection is likely elevated above this cap Alas, in Chicago, we are getting rain and weak thunderstorms here, I thought I would wake up to 70 mph winds and tornado sirens given last night's potential, but no dice. Iowa convection looks interesting, but I think we need more heating. Given this morning's activity, there has got to be widespread outflow sitting out there. Let's kill that cap, lol! I may venture out locally toward Dekalb or something this afternoon.
 
Starting From NW OH. Plan on heading West into IN probably 100 miles or so. There seems to be some clearing there and a little bit of sun would help. Chance of supercells looks a little more favorable, line is of courses still likely. Will head west and check for data in the next few hours. I expect things will be fairly early today.

The rain just ended here in Findlay.

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Tom Hanlon
 
Just a few minutes ago SPC has issued a severe thunderstorm watch for northern Illinois, northwestern Indiana, southeastern Minnesotta, Lake Michigan and Southern Wisconsin. I'm packing up and heading out in the next hour or so. Heading up to Remington, IN to a friends farm and hanging out there until initiation starts up and decide where to go then. Its sunny and heading towards 90 for the high today and the dewpoints look good. Im out for now.
Eric
 
Severe Watch #527 just issued about 10 minutes ago for IL/WI. I was looking at the probablities of severe events for this watch. They seem high, wouldn't this warrant a PDS? Still a lot mid-level clouds all over the place, some CINH is eroding especially to the south. It looks like an elevated MCS producing isolated large hail will be the main event today. I'm not impressed, so I probably will not be heading out unless I see sunshine and explosive cumulus like it was on May 25th in MO.
 
With Cape exceeding 3,500 j/kg and LI's of -7 In East/North Central Illinois, I think I'll take the Watseka, Illinois area. Good luck to all, could be interesting!!! :D
 
I don't think the motion on the Guthrie Co. storm is that preplexing...it's right along an outflow boundary, so individual cells are prob firing along it to the southwest while the cells move towards the east giving it the SE motion. Not sure if we will get a bow or anything significant out it (A little early to tell)...but the profilers and VADs around the area sure don't point towards it as the shear isn't all that great and the little Guthrie Co line looks to be just settled on the bndry (had to change what I said----confused myself on the location flipping back and forth from GE to internet maps)
 
Well I just animated the SBCAPE/CINH map at SPC. The cap is weakening substantially, especially in W C IL. I thinks some serious initiation might be in the cards over the next hour or so. The sunshine is starting to break out here in the Metro area. I like our dewpoint depression of 8 degrees right now as well. Puffs of low level cumulus are showing up in the sky, but midlevel altocumulus and some stratus is still present. The air is juicy!
 
Looks like we are gonna chase a squall line. Tryin to guess the southern end for some better tor chance. Will head to South Bend and then down from there on Rte 31. Plenty of instability inplace. See what happens when that line heads east.

IN/IL looks good but a little far from here. Ft wayne Indiana shows promise also, guess we will play the middle of that.

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Tom Hanlon
 
Well I just animated the SBCAPE/CINH map at SPC. The cap is weakening substantially, especially in W C IL. I thinks some serious initiation might be in the cards over the next hour or so.....The air is juicy!
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Parameters do look pretty impressive now for initiation over W Central IL this afternoon. Even more impressive, though, are indications for central and northern Indiana later this afternoon/early evening. Check out the 6-hour RUC. Nice pooling of theta-e, and SB CAPE of over 4,500 j/kg. Also, even lower LCL's, some decent low-level shear and 50-60 kt flow at 500mb crossing over 30-40 kt flow at 850mb at about a 45 degree angle.

Re: Alex's comment about the ESE motion on the Iowa storm, note this is consistent with the storm motion estimates for that area on the SPC's mesoanalysis. BTW, does anyone know if the SPC uses the Bunkers method for this estimate, or just the mean 0-6km wind?
 
18Z winds across southern MI are southeast - GFS & NAM both said we should be firmly in SW flow by now. RUC has a much more curved hodo at 21Z than any other model...

18Z soundings flown at DTX / GRB / ILX / DVN / APX - nothing spectacularly different.
 
Re: Alex's comment about the ESE motion on the Iowa storm, note this is consistent with the storm motion estimates for that area on the SPC's mesoanalysis. BTW, does anyone know if the SPC uses the Bunkers method for this estimate, or just the mean 0-6km wind?
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Looking at the 0-6km shear in the area, looks like they use Bunkers. However, Bunkers is for supercells and I don't think that those storms were very supercellular. The storms have looked like they have weakened, however the Clark Co storm has some hail spikes at the upper tilts, so it may have just come back up.
 
Now, I am sitting in Rochelle, IL with Kurt Hulst and Fabian Guerra...and we are waiting, just waiting. The air here is very humid, dew points are pretty high, but LCL's are ascending, unfortunatly....but north of here, they are still relativly low.....There are some cumulus fields developing around us....but we are right on top of that boundary here in IL....I still, am skeptical about tornadoes today...
 
I'm still trying to decide which cluster of storms presents the biggest risk of turning into a significant MCS - the stuff now in WI, or that stuff that's been developing back in central IA?

The stuff in WI isn't looking real impressive, with little vertical development seen on the VIS loop. The stuff in IA is a bit different, with what appears to be good vertical growth in a linear fashion along an outflow boundary.

Now that the sun is out and things are rapidly becoming unstable across southern WI/ northern IL/northwest IN, we should see some development in that area, or so I would suspect.
 
I'm still in Detroit, and probably won't head west until things come a bit more clear (in the next couple of hours quite likely). Latest SPC mesoanalysis shows considerable moisture/deep-layer convergence across eastern WI (in an area of weakened CINH) with strong (SB/ML)CAPE already developing over much of the southern Great Lakes. Its nice to the see the deep-layer shear vector generally aligned normal to the boundary forcing ascent -- so the main mode of convection could likely be supercells across much of WI and perhaps into northern IL (upon first initiation) given the degree of deep-layer flow, with a casual upscale growth to a large-scale bow complex later this evening. I don't think it'll be much longer until things get going (as the strong 500mb shortwave perturbation and large-scale height falls continues to move into the area) as we continue to destabilize and boundary layer parcels are able to attain their LFCs as the CINH layer is breached (and updrafts interact with the sheared flow and begin to rotate and develop VPGFs which will contribute to further intensification).
 
I'll be leaving Champaign soon and likely just heading north into northern Illinois. Cu field is starting to develop up that way, and cinh is eroding quickly. I expect to either see new storms developing along the boundary in that area, or to see more extensive growth on the storms occuring in south central Iowa right now. Of course if this happens, I'm sure we'll just get a big bow echo to march across the northern half of the state so I'd much rather see some isolated (though breifly isolated) cells develop up north. Either way, looks like an active day. Should be several rounds of storms along this boundary across the moderate risk area continuing into tonite.
 
Grunge and extreme humidity is the rule here right now. It looks like a line of showers is going to push through here in the next 1-2 hours. The satellite shows clearing and cumulus fields to the SW of here. I'm still thinking of heading out, but i need more convincing. The cap is doing something that it didn't do yesterday though, it's eroding! A forecast sounding says the convT is about 83 degrees, so we'll see.

EDIT: It's 87/71 here now, the clouds ain't stopping the heating. ConvT is about 91F on the NAM
 
EDIT: It's 87/71 here now, the clouds ain't stopping the heating. ConvT is about 91F on the NAM
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93/65 and not a cloud in the sky in P-town. Plenty of haze, though...

Here stormy.. stormy.. stormy....
 
Now that the sun is out and things are rapidly becoming unstable across southern WI/ northern IL/northwest IN, we should see some development in that area, or so I would suspect.
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We have had very little sun here halfway between Milwaukee and Madison and have been under a light drizzle for the past 1/2 hr.

Still, I see clearing on the radar about an hour to the west. With all this soup in the air, all it'll take is an hour or 2 of insolation.
 
Some of the forecast soundings across southern lower MI (and northern IN) for the 00z timeframe are just georgous. The JXN (Jackson MI) and OEB (Coldwater MI) RUC forecast soundings for 00z are just awesome (click on the 06FH to the left), with strong deep-layer and low-level shear (and very large >3500j/kg CAPE progged by the late afternoon) supporting long-lived, organized convection -- and given the shear profiles (with enlarged and relatively-curved hodographs), I could still see isolated tornadoes being a threat even as far east as Detroit Metro by the late evening (with the strong mechanical mixing likely preventing boundary layer de-coupling and inversion development to a large enough extent to allow for surface inflow). While the profiles are generally unidirectional, there is plenty of low-level veering (pronounced boundary layer WAA profiles) which yields >200m2/s2 0-1km SRH by the 00z timeframe (albeit mostly SW sfc flow).

I will likely head southwest shortly (hopefully initiation will occur near the warm front in the next hour or so).

EDIT: Earl's RUC soundings were showing the 15z run (and it's now been refreshed to the latest 18z run) -- so please click on the FH06 and not FH09 like I said 10 minuites ago :lol:
 
i stand by my statements eariler, saying the mod. risk should be shifted south. I'm doubting more and more any severe storm threat from about a Grand rapids/Detroit line north. Temps still have not made it out of the low 70s across much of that area and the clouds are hanging tough. If anyone disagrees, could you post the reasons why, i would like more opinions, thanks.
 
Sitting at FlyingJ in Gary, IN with Eric Flescher, and feeling really good about being right where I am. MCD just issued for I-80 corridor for initiaiton within 1-2 hours and isolaed TOR risk. I like the end of the line advancing toward us from the west. But there are a few decent towers starting here. Problem, in my estimation, is the lack of cap. I'd rather be sseing just a bit of cap right now to let them bubble some ;-)
 
i stand by my statements eariler, saying the mod. risk should be shifted south. I'm doubting more and more any severe storm threat from about a Grand rapids/Detroit line north. Temps still have not made it out of the low 70s across much of that area and the clouds are hanging tough. If anyone disagrees, could you post the reasons why, i would like more opinions, thanks.
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The soundings out of PTK at ~00z show roughly 3000j/kg of CAPE with a sfc t of just 75F. Hodographs also looking very nice. Still, monster instability is present south of the state line with 5200j/kg being seen.
 
The soundings out of PTK at ~00z show roughly 3000j/kg of CAPE with a sfc t of just 75F. Hodographs also looking very nice. Still, monster instability is present south of the state line with 5200j/kg being seen.
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Yeah, I agree... Current sfc analysis shows the warm front just south of I94 right now and curving east-southeastward (with the strongest low-level shear residing just north of the front in southern MI) with small cumulous fields now developing south of the front (check visible satellite imagery) with 3000-4000j/kg of SBCAPE already developed along and just south of I80 (per SPC mesoanalysis) with dramatically weakening CINH. I'm thinking of just heading west on I94 and checking data when I get towards Battle Creek. I don't neccessarily think I'll have to chase out of the state today (at least I'm hoping LOL).

I'm guessing SPC will go with a red box soon.

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lower LFCs in the region of developing Cu (and >3000j/kg CAPE and >45kt deep-layer shear) and enhanced sfc moisture convergence. I'm heading on I94 in a few minuites towards Battle Creek (I'll check data near I69, however).
 
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