8/15/07 NOW: IN

[rdale]

Ehhh, I don't think that's showing a long-tracked supercell ;> Plus none of the storms it shows in Michigan exist.

 

[Danny Neal]

Quite suprisingly, the NSSL WRF strikes again. It's typically spot on, and even at 30 hours: http://www.nssl.noaa.gov/wrf/rflslp30.png

I have noticed in the past few days that it has been "fairly" accurate. Lets see if that secondary MCS develops over NW IL and storms my way by dawn. Meh.

 

[Bob Hartig]

Can't believe I'm still watching this thing. I was ready to give up on it, thought the supe was all but subsumed by the line, but it pulled together nicely just north of Amboy with a nice V-notch, and now it's nicely defined again with a decent hook and a TVS to go with it.

Interesting array of gust fronts, by the way. There's a hint of an OFB ahead of the whole pack, then the easily distinguishable one for the main line, then another...like three waves one after the other.

Second line is looking nasty.

 

[Robert Dewey]

In response to Rob Dale: Ummm... Sure, but you can't argue the verification of the bow echo. You might also be forgetting that the timestep is 30 hours - pretty damn good IMO. With the 4km resolution, defining a tail-end charley would probably be pretty difficult. Hell, the 12Z NAM didn't do as good of a job... If MI starts popping small showers/cells in the next couple of hours, I'll be satisfied with the performance...

Anyway, to keep on topic... Kosciusko looks like they got hit pretty hard with that bow echo around 11:40ET. Nice inflow notch was evident, with SRV1 in excess of 55knts, and a very nice bow-out as it passes through the county. The tail-end charley was decent looking and quite persistent, but rotation didn't look jaw dropping... at least on L3.

 

[David Draun]

Wow! GRLevel3 was showing 12 MESO markers and 6 TVS's on that cluster of storms on the last scan! That supercell is still discrete as it storms ahead of the advancing bow echo. Quite a fat hook that thing is sporting!

Here's to hoping for that secondary MCS forming in NW IL, haven't had a decent storm here since last Wednesday.

 

[MatthewCarman]

Anyone have any pictures saved of this line of storms? If so can you please post one on here for me. Thanks.

 

[Danny Neal]

Wow! GRLevel3 was showing 12 MESO markers and 6 TVS's on that cluster of storms on the last scan! That supercell is still discrete as it storms ahead of the advancing bow echo. Quite a fat hook that thing is sporting!

Here's to hoping for that secondary MCS forming in NW IL, haven't had a decent storm here since last Wednesday.

Agreed, That storm is moving into the Marion, IN area. I'd expect to hear/see some reports coming in outta that area with this nasty storm. Maybe a watch further to the S and E is on tap? I keep waiting for it to lose the boundary its riding and bow out and it just doesn't seem to want to happen.

 

[Robert Dewey]

Latest scans look like it's becoming disorganized... I think it might be going linear. Think is the keyword here, heh.

 

[Bob Hartig]

Agree. It's looking mushier. So what's with all the TVSs? Hard to take them all that seriously when there are so many of them all over the place without anything in SRV that seems to corroborate them. Can one of you mets explain? (Or maybe that's a separate thread!)

 

[Robert Dewey]

IWX BREF2 showing a weak hook again... wonder if it will organize down to the SFC. Doesn't look real strong (rotation-wise)... But I could imagine it putting down a brief weak TOR.

EDIT: On second thought... that outflow blowing out is a good indication it might be done.

 

[rdale]

Looks like IWX has their critera set very VERY low for TVS.

Re: NSSL WRF -- when you replied specifically to the post about nobody expecting a HP supe, I assumed you meant the NSSL WRF called it ;>

Tornado reported in Marion Co per trained spotter, but per the time stamp the storm was about 10 miles east at the time.

 

[Jeff Snyder]

Agree. It's looking mushier. So what's with all the TVSs? Hard to take them all that seriously when there are so many of them all over the place without anything in SRV that seems to corroborate them. Can one of you mets explain? (Or maybe that's a separate thread!)

Individual NWSFOs can modify the criteria used to trip TVS and meso signatures. In this case, it's possible that the office 'responsible' for the IWX radar is using more sensitive criteria, thus resulting in more TVS and meso signatures. In addition, shear long strong gust fronts / outflow boundaries can be strong enough to trip those signatures as well. I'm not an operational forecaster, so perhaps someone else can chime in (if so, please use a different thread).

Nice to see some strong bow echos this past week. Mesoanalysis was showing that surface parcels should be quite stable (significant CINH), which may mean the strongest winds aren't translating to the surface very efficiently. Regardless, 0.5 degree BV data showing large areas of >57kt outbound velocities. Given that the bow echo isn't quite parallel (or antiparallel) to the radial(s) at those particular azimuths, the actual low-level wind speeds may be 10-20kts higher.

 

[rdale]

Feeding info to Grant Co EMA via IEM right now (Marion area where those 57kt+ outbounds are showing) and he reports some gusty winds but nothing extreme. ASOS reports from the line have been in the 30-40kt range.

 

[Andrew Kajfasz]

I've been hearing spotter and LE reports that there has still been some rotation in Kokomo, IN, and around Marion. Also, Van Wert County in Ohio has now been issued a tornado warning with reports of nickle size hail, strong rotation, and wind gusts of 80MPH plus.

 

[Danny Neal]

Still looks to be numerous inflow notches along the forward flank of the MCS. As for Van Wert county looks like the comma head is wreaking havoc which isn't a huge surprise. I would expect to see more TOR warnings issued based on the extreme shear along the gustfronts and LEWPS.