7/19/06 NOW: MN / IA / WI / IL

[John Wetter]

Of course they can!! I'm not sure how old you are, but the TV "weathermen" (not even mets) used to do that all the time back in the 1960's and 70's if they wanted to focus in on a particular area of concern. So, don't tell me an operator in this day and age can't do the same thing. So, it's not that they "can't" do it...it just seems very unprofessional.

If anyone has a logical, alternative explanation for all these extreme radial anomalies over mid-continent radars lately, I'm all ears.
[/b]

I think everyone has seen them do that with the old radars... Yes, you could do that in the old radar, but there is no way to do that with the 88d when it's in operational mode. It is in a VCP - Volume Coverage Pattern - The radar is always rotating. You simply can't stop it and point... The whole point of the system is to get full volumes for all of the integrated products. The explaination is no harder than to look at the meteorology of what has been going on over the plains recently. Huge heat with huge inversions so there is tons of ducting so you get a perfect environment for seeing surface features and seeing lots of sun spikes.

On the original topic, storms are now firing in MN. FSD just issued a TOR warning for Watonwan county and the storm looks pretty nice. A decent boundary out there it seems. Surprised there isn't a new box up yet as the mod has come back north to MN and the storms went from blips to sups in about 35 minutes.

-John

 

[Dan Cook]

Pretty big echo tops from those cells:

http://www.midwestchasing.com/images/top.png

 

[Jonathan Whitehead]

I watched the MCS blow thru downtown St. Louis just outside Bush stadium on a live streaming webcam as 40,000+ were set for first pitch. From what I witnessed, it was one of the most vicious and severe storms ive witnessed in quite some time. The sky was downright pitch black minutes before the rain hit as i saw both on the webcam and on local Ch. 7 here in OKC metro that was to carry the game. And the wind as it went thru was insane, just incredible straight line winds. Absolutely incredible straight line winds.
The announcer whom I have to believe is getting inside information announced that 350,000 people in St. Louis/E. St. Louis area were without power and that 92mph winds went thru downtown. I would have to believe that not only from what I saw but most announcers wouldnt throw out such exact numbers like that.
I mean this was a viscious storm. St. Louis and E. St. Louis will be cleaning up from this one for days. I dont have any pics of course but I didnt find this one image off www.atlantabraves.com of the tarp that ripped during the height of the storm. The grounds crew had to bring out a mini bulldozer to redo home plate b/c when the tarp ripped, it exposed homeplate and it become a small lake.

 

[Jeff Snyder]

What is going on with these ridiculous radial reflections on the radars over the mid-continent? If I didn't know any better, it almost seems like the operators are sitting there focusing their beams across a very narrow cross-section. I mean, the outflow boundary visible over central IA was there for all to see, but there is no need to focus the damn beam on it; that only distorts the true picture! And, by the way, guys, if you do it long enough it produces storm rainfall totals which actually don't exist...therefore contaminating national databases! What junk! Just let your radar function as it is supposed to. It seems to happen in Des Moines, Topeka, and Omaha in particular.
[/b]

You aren't referring to the radial spikes you seen when the sun sets or rises, are you? You'll often see radial "spikes" start along the east coast, and work westward in time. IIRC, this is caused by the radar directly measuring some solar radiation as the sun sets... The radial(s) contaminated will be "pointed" at the sun (e.g. in the winter, they are oriented with a southerly component; in the summer, the radials affected are those directed with a northerly component -- e.g. at 290 degrees).

This day went down surprisingly like 6-20-06. A "waste" of a setup from a chaser's perspective, I must say. Chasers -- 0; 2006 -- 50.

EDIT: I don't like keeping the MDT risk. The cap held through peak heating and beyond, and I don't know how you'd get surface-based convection when the surface layer is cooling... It seems to be more of a CYA outlook (at least in terms of tornado probs). Storms in MN are about to cross into IA and may be nasty, since MUCAPE is still relatively significant. But I think 10% tornado prob is uncalled for given that temps ahead of the MN convection are in the 70s (90s weren't able to do it, so 70s certainly won't). We shall see, I suppose, since SPC just issued another tornado watch for the area. I guess it's a case of whether storm-scale processes can allow for a storm-induced vortex to exist at the surface (e.g. rotation extending all the way to the sfc). We've seen noctural tornado events before, that they tended to be during periods of strong winds overnight, from which the mechanical mixing may have helped prevent a strongly stable layer from forming near the ground.

 

[Andrew Pritchard]

Much of St. Louis is without power right now. (have to imagine that's going to hurt when heat indicies reach 115-120F tomorrow afternoon)

Many reports coming in from downtown St. Louis of some fairly extensive damage from the straight line winds, which did in fact reach 90 mph in places.

 

[David Draun]

Convection is now becoming widespread in MN, IA and western WI. It looks like mr. big nasty MCS is now in it's developing stages. It appears that this could follow the same path as this morning's system, as the better parameters are staying south and west of here.

 

[Terry Tyler]

Is this one of those "3-Body Scatter" things, or a hail spike? I read something about that kind of signature, and when put in motion...its right behind the hail producing storm. Is this a rare event?

 

[Jeff Snyder]

Terry,

I'm not entirely sure what that is, though I've seen it before too. TBSS usually looks more like a "spike" sticking radially outward from the storm (and it looks pretty cool in GR2AE), in contrast to the 'skipping signature' that the radar grab shows. From the lots of the screen grab, you're using the Des Moines radar (right?), and looking at storms between I90 and the Twin Cities, which means that the beam is very high above ground (more than 25,000 feet in this case) (and likely a ways above the freezing level -- wet hail tends to have the highest reflectivity). Then again, in an updraft (a warm Tv perturbation, the local freezing level is higher, and hail will be lofted above that level (e.g. dry growth phase).

TBSS are not entirely "rare", from my experience, but they aren't too common either. I've probably seen 15 storms this year with a TBSS, which might mean something given the lack of substantial supercells in the Plains this year.

 

[David Draun]

New MD and watch now in effect from SE MN south and east to Chicago Metro area until 7 AM CDT. Looks like one big'ol ice-factory of an MCS is developing out there. Hail parameters are spiking with this activity. Too bad I gotta sleep soon.

 

[Dan Robinson]

Still hanging out here in Merrillville. I'd like to be optimistic about the much-anticipated and finally-developed MCS, but there is just no real instability to be found this far east. Everything that has managed to pop up over here has fizzled, accomplishing nothing more than further stabilizing our atmosphere. I think it is interesting that mesoanalysis shows zero MLcape over northeast IL, yet there is still a small amount of (diminishing) surface based cape and LIs of -7 as of a couple of hours ago (from the 2 or 3 hours of sunlight earlier today I assume). Since the storms will be elevated when (if) they get here, they won't be tapping any of that - so where they will be getting their juice from (as the watch implies) I'm not fully understanding. Will the LLJ/shortwave combo provide forcing to work with near-zero CAPE?

HPC, SPC and the RUC and GFS seem to think so - so I'll stay awake for a while. My other issue is that I'd like for it to be DARK to shoot lightning slides - hoping it speeds up a little and gets here before sunrise.

 

[Mike Hollingshead]

That high dbz blip was interesting in nw IA. That was about all that was. My car began to overheat so I stopped for a while. I then glance at radar and see this intense little blip pop up. I trace where I am in relation to it and it was right on me lol. It was right over those wind farms like was mentioned. Those elevated showers were moving to the southeast and I kept thinking there HAD to be some taller tower around causing that. I looked and looked. All I was seeing were lots and lots of wind turbines.

 

[Kevin Bowman]

chicago is setting up to get hit pretty hard, though i dont think it will be as bad as st louis earlier in the day

 

[Danny Neal]

just took a lightning bolt to a tree outside my house, they say the worst of it is gona come at 450 AM i have my anemometer all ready to go for this beast!!! the highest i ever got on that thing was 57 mph! gona try to beat that in 20 mins

 

[Kevin Bowman]

much to do about nothing, shouldve just gone to sleep. probably had 1 50mph gust, very little lightning and thunder compared to the show on monday night

 

[David Draun]

Nothing too impressive here either. I don't think the wind got above 40 mph as the bow went through. Lightning is few and far between despite one close CG hit. Totally weak. :-(