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March 2 Severe Potential and Observations


Indystorm

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ECVS120622015.GIF

West Liberty is roughly due south of Detroit and even with the southern border of Indiana. You can see the dueling supercells, as well as the storms to the west, have anvil blow off that is roughly shading the areas to the north of that line. West Liberty was right about on that boundary. And of course it appears the West Liberty storm provided the outflow that the Saylersville supercell ingested.

Nice shot. You can practically pick out individual cells across the area.

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I'm not exactly sure that anvils or outflow made the West Liberty and Salyersville storms so strong. They were in an environment of 800 m2/s2 0-1km helicity. All they needed to do was to hit the relatively backed windfield in far eastern KY to explode. The fact they were the farthest east of the storms in KY meant they had unimpeded inflow and they were able to hit the backed flow earlier before the boundary layer stabilized from nocturnal cooling.

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I'm not exactly sure that anvils or outflow made the West Liberty and Salyersville storms so strong. They were in an environment of 800 m2/s2 0-1km helicity. All they needed to do was to hit the relatively backed windfield in far eastern KY to explode. The fact they were the farthest east of the storms in KY meant they had unimpeded inflow and they were able to hit the backed flow earlier before the boundary layer stabilized from nocturnal cooling.

There were a lot of storms in that same type of environment though. All I'm suggesting is that there may have been an "anchor" that helped those supercells focus the environment. Especially with how quickly those two storms developed, a la Joplin. These were low level meso that went from relatively broad circulations to intense 200 kt couplets within a couple volume scans. I think of how the morning convection across northern Alabama and southern Tennessee laid down multiple boundaries across northern and western Alabama on April 27th.

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It'll be interesting to see if that Henryville cell had a continuous tornado track.  The tornadic part passed through the dense Hoosier National Forest prior to reaching the Henryville area so it's possible that a touchdown happened earlier than what it seems.  Area isn't very easy to access by road so I assume aerial surveys will come in handy.

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I'm not exactly sure that anvils or outflow made the West Liberty and Salyersville storms so strong. They were in an environment of 800 m2/s2 0-1km helicity. All they needed to do was to hit the relatively backed windfield in far eastern KY to explode. The fact they were the farthest east of the storms in KY meant they had unimpeded inflow and they were able to hit the backed flow earlier before the boundary layer stabilized from nocturnal cooling.

Once again proving models cannot be trusted in judging LL shear.

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It'll be interesting to see if that Henryville cell had a continuous tornado track.  The tornadic part passed through the dense Hoosier National Forest prior to reaching the Henryville area so it's possible that a touchdown happened earlier than what it seems.  Area isn't very easy to access by road so I assume aerial surveys will come in handy.

Hopefully there's a way to do aerial surveys with local law enforcememt because word came down this week that civil air patrol for surveys is no longer being funded, another casualty of the budget cuts. Not sure of that meant next fiscal year though.

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:drunk:

Well it's not as if the guidance was completely out to lunch. The NAM forecast 24 hours out were at least 500 m2/s2. We knew there was a significant outbreak on the way, but as is typically the case with rapidly deepening systems the ageostrophic flow is underdone. That's where conceptual models come into play.

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It'll be interesting to see if that Henryville cell had a continuous tornado track. The tornadic part passed through the dense Hoosier National Forest prior to reaching the Henryville area so it's possible that a touchdown happened earlier than what it seems. Area isn't very easy to access by road so I assume aerial surveys will come in handy.

The following video is supposedly during the formation stages. Although the treeline obstructs the view, I see what appears to be a power flash near the beginning of the video. Shortly after, you can see that it's obviously on the ground. Then, it appears to dissapate/lift, before touching down again and finally wedging out. It's not clear-cut, but it did seem to lift for a couple of minutes.

http://www.youtube.com/watch?v=KddQS42SO6M

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The following video is supposedly during the formation stages. Although the treeline obstructs the view, I see what appears to be a power flash near the beginning of the video. Shortly after, you can see that it's obviously on the ground. Then, it appears to dissapate/lift, before touching down again and finally wedging out. It's not clear-cut, but it did seem to lift for a couple of minutes.

It does appear to have lost contact with the ground for a brief time there, as there was no debris cloud near the distant tree line. Some violent rotation in those clouds though, you could tell it was ready to drop a monster just before the condensation funnel became visible again late in the video. The inflow into that storm was impressive, even had an inflow tail visible coming into the backside of the wall cloud.

Impressive RFD dry slot wrapping around the backside too.

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EF-3 confirmed in Ripley County IN (Holton)

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE WILMINGTON OH

542 PM EST SAT MAR 3 2012

...TORNADO CONFIRMED NEAR HOLTON IN RIPLEY COUNTY INDIANA...

LOCATION...HOLTON IN RIPLEY COUNTY INDIANA

DATE...3/2/2012

ESTIMATED TIME...4:00 PM EST

MAXIMUM EF-SCALE RATING...EF3

ESTIMATED MAXIMUM WIND SPEED...145 MPH

MAXIMUM PATH WIDTH...350 YARDS

PATH LENGTH...10-11 MILES

BEGINNING LAT/LON...39.0827/-85.3497

ENDING LAT/LON...39.1126/-85.2570

* FATALITIES...2

* INJURIES...UNKNOWN

* THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO

CHANGE PENDING FINAL REVIEW OF THE EVENT(S) AND PUBLICATION IN NWS STORM DATA.

...SUMMARY...

THE NATIONAL WEATHER SERVICE IN WILMINGTON OH HAS CONFIRMED A

TORNADO NEAR HOLTON IN RIPLEY COUNTY INDIANA ON 3/2/2012.

THIS INFORMATION CAN ALSO BE FOUND ON OUR WEBSITE AT

WEATHER.GOV/ILN.

FOR REFERENCE...THE ENHANCED FUJITA SCALE CLASSIFIES TORNADOES INTO THE FOLLOWING CATEGORIES:

EF0...WIND SPEEDS 65 TO 85 MPH.

EF1...WIND SPEEDS 86 TO 110 MPH.

EF2...WIND SPEEDS 111 TO 135 MPH.

EF3...WIND SPEEDS 136 TO 165 MPH.

EF4...WIND SPEEDS 166 TO 200 MPH.

EF5...WIND SPEEDS GREATER THAN 200 MPH.

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Looking back at yesterday, it appears that the Henryville tornado occurred in an environment with no more than 1000-1200 J/kg MLCAPE. I suspect that is lower than a majority of documented violent tornado cases, although it was enough in this case.

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Well it's not as if the guidance was completely out to lunch. The NAM forecast 24 hours out were at least 500 m2/s2. We knew there was a significant outbreak on the way, but as is typically the case with rapidly deepening systems the ageostrophic flow is underdone. That's where conceptual models come into play.

Yeah, looking back at the models with respect to this event the NAM was the clear winner by a wide margin. Showing the closest shear profile and instability, although both were underdone by the NAM, the GFS was forecasting for another planet I guess because it wasn't even remotely close. I believe the Euro/Ukie fell somewhere in between but closer to the NAM.

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The following video is supposedly during the formation stages. Although the treeline obstructs the view, I see what appears to be a power flash near the beginning of the video. Shortly after, you can see that it's obviously on the ground. Then, it appears to dissapate/lift, before touching down again and finally wedging out. It's not clear-cut, but it did seem to lift for a couple of minutes.

The tail end of the video is amazing, it goes literally from nothing to a monster wedge in under 45 seconds. That is downright impressive.

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I can dig for the info but can anyone remember who/when first posted about this storm? I assume it is in the February banter & obs thread...

I don't know about the first one on here... but I mentioned it February 26th...

Danny Neal

February 26 near Evergreen Park

Dixie Alley may have a pretty big outbreak a week from now if you believe the Day 7 ECMWF from earlier today... that was the "2nd" system I was referring to earlier today

After that our group Convective Addiction did numerous forecasts and an SPC high risk verification article.

http://convectiveadd...k-verification/

http://convectiveadd...break-expected/

http://convectiveadd...ather-outbreak/

I was personally forecasting this since the 27th... but I have posted enough links. Definitely a day no one will soon forget and one of those times that you hope the models are wrong...

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I don't know about the first one on here... but I mentioned it February 26th...

After that our group Convective Addiction did numerous forecasts and an SPC high risk verification article.

http://convectiveadd...k-verification/

http://convectiveadd...break-expected/

http://convectiveadd...ather-outbreak/

I was personally forecasting this since the 27th... but I have posted enough links. Definitely a day no one will soon forget and one of those times that you hope the models are wrong...

I was just reading through the spring speculation thread and it seems Hoosier brought it up around that time too.

I'm gonna sort of go out on a limb and predict that some area of this forum will have a moderate or high risk before March 15.

March 2?

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