• Welcome to TalkWeather!
    We see you lurking around TalkWeather! Take the extra step and join us today to view attachments, see less ads and maybe even join the discussion.
    CLICK TO JOIN TALKWEATHER

Archive Severe threat April 26-27, 2011

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Fred Gossage
Posted 25 April 2011 - 10:31 PM

ALhurricane, on 25 April 2011 - 10:25 PM, said:

SREF sig tor parameters are nearly identical to what we saw on April 15th...with a slight shift to the north. Also, a look at the shear vectors indicates to me that it will take a long time to line out on Wednesday with long lasting discrete activity. If I were SPC, I would extend the new day 2 MDT risk further south to encompass portions of S AL/MS.


Agreed... think we need to expand the MDT south and westward... not completely sure how far south... but back to I-55 in central MS.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Fred Gossage
Posted 25 April 2011 - 10:33 PM
TimHSV, on 25 April 2011 - 10:28 PM, said:

I dont think I've seen this type of shear with such high velocity returns on a SRV before? Pretty amazing


When you have your velocity selected there Tim, hit the little red/green button at the top next to the smoothing button. That's a dealiasing algorithm for velocity that tries to fix some of the errors. Keep that on for BV and SRV at all times, sir
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
TimHSV
Posted 25 April 2011 - 10:33 PM

ALhurricane, on 25 April 2011 - 10:25 PM, said:

SREF sig tor parameters are nearly identical to what we saw on April 15th...with a slight shift to the north. Also, a look at the shear vectors indicates to me that it will take a long time to line out on Wednesday with long lasting discrete activity. If I were SPC, I would extend the new day 2 MDT risk further south to encompass portions of S AL/MS.



I wish you would post those shear vectors and circle them? That would be an interesting item for a more learning experience,in which I think that would enlighten a bunch of us for sure
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
aarontabr
Posted 25 April 2011 - 10:33 PM

2 Fatalites in Arkansas.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
bingcrosbyb
Posted 25 April 2011 - 10:34 PM

Unconfirmed reports from Faulkner County EMA: 2 fatalities in Vilonia.
Edited by bingcrosbyb, 25 April 2011 - 10:35 PM.

 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
bingcrosbyb
Posted 25 April 2011 - 10:48 PM

Falkner Co. EMA now telling people via scanner NOT to bring chainsaws/supplies to Vilonia. All roadways into the town are too dangerous for travel.
Edited by bingcrosbyb, 25 April 2011 - 10:49 PM.

 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
ALhurricane
Posted 25 April 2011 - 11:05 PM

TimHSV, on 25 April 2011 - 10:33 PM, said:

I wish you would post those shear vectors and circle them? That would be an interesting item for a more learning experience,in which I think that would enlighten a bunch of us for sure


Wish I had time to illustrate, but here is a quick summary...

When you are looking at various wind fields...overlay several layers (sfc, 850, 700, 500, 250). Whenever you have a near 90 degree turning from the sfc to the upper levels it favors right moving supercells (large curved hodographs). This is in large part due to the updraft propagation being perpendicular to the shear vector. A good paper to read is... http://www.nwas.org/digest/papers/2005/Vol29No1/Pg81-Zeitler.pdf

Another rule of thumb is that when the deep layer shear vector is perpendicular to the boundary (cold front, dry line, etc.) it favors longer lasting discrete cells. April 15th was a great example of this. The convection forced ahead of the cold front stayed primarily as a line of broken discrete supercells through the afternoon and evening.

This is just a quick attempt at a simplified explanation. A lot of other factors play a role...such as the organization of cold pools.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
bingcrosbyb
Posted 25 April 2011 - 11:07 PM

Associated Press:
Quote

Faulkner County spokesman Stephan Hawks says one person died in the central Arkansas town of Vilonia, where a path of damage stretches three miles wide and 15 miles long.

Edited by bingcrosbyb, 25 April 2011 - 11:08 PM.

 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
PTH
Posted 25 April 2011 - 11:08 PM

Any estimates on when tonights line of storms will reach west central Alabama?
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Fred Gossage
Posted 25 April 2011 - 11:09 PM
bingcrosbyb, on 25 April 2011 - 11:07 PM, said:

Associated Press: path of damage stretches three miles wide and 15 miles long


I would be very weary of that width until survey time. A good bit of that is quite possibly RFD damage south of the tornado track.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
SWL
Posted 25 April 2011 - 11:12 PM
PTH, on 25 April 2011 - 11:08 PM, said:

Any estimates on when tonights line of storms will reach west central Alabama?


I'm guessing around daybreak
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
aarontabr
Posted 25 April 2011 - 11:20 PM

SPC ought to decide soon if a watch is needed for north Alabama.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
ZackH
Posted 25 April 2011 - 11:26 PM

aarontabr, on 25 April 2011 - 11:20 PM, said:

SPC ought to decide soon if a watch is needed for north Alabama.


Well the line will be moving into more stable air as it nears Alabama at this stage, so there may be a watch, but I don't think we'll see any huge severe event from this line in Alabama. The next shortwaves are what AL needs to be watching.
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Fred Gossage
Posted 25 April 2011 - 11:29 PM

ZackH, on 25 April 2011 - 11:26 PM, said:

Well the line will be moving into more stable air as it nears Alabama at this stage, so there may be a watch, but I don't think we'll see any huge severe event from this line in Alabama. The next shortwaves are what AL needs to be watching.


And I would hope, if they issue a watch for part of Alabama for this line tonight.... the flavor is blueberry.

 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
TimHSV
Posted 25 April 2011 - 11:33 PM

Fred Gossage, on 25 April 2011 - 10:33 PM, said:

When you have your velocity selected there Tim, hit the little red/green button at the top next to the smoothing button. That's a dealiasing algorithm for velocity that tries to fix some of the errors. Keep that on for BV and SRV at all times, sir.


LOL Fred. I do keep it pressed on at all times, but for some odd reason, it was turned off! ...Good catch bud
Edited by TimHSV, 25 April 2011 - 11:34 PM.

 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Guest_duckfetchr_*
Posted 25 April 2011 - 11:34 PM

Fred Gossage, on 25 April 2011 - 11:29 PM, said:

And I would hope, if they issue a watch for part of Alabama for this line tonight.... the flavor is blueberry.

eh?
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Tyler Penland
Posted 25 April 2011 - 11:37 PM

Fred Gossage, on 25 April 2011 - 11:29 PM, said:

And I would hope, if they issue a watch for part of Alabama for this line tonight.... the flavor is blueberry.


Meaning SVR watch cause its blue?
 

TW Archive

Member
Don't Feed The Bots
Messages
2,028
Reaction score
23
Fred Gossage
Posted 25 April 2011 - 11:38 PM

Tyler Penland, on 25 April 2011 - 11:37 PM, said:

Meaning SVR watch cause its blue?


Yes.
 
Back
Top