• 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

Severe WX Severe Weather Threat 3/14-3/16

UncleJuJu98 said:
This is the 00z CSU severe probability great placement imo. View attachment 35301
Click to expand...
I believe those are 00Z aggregate values.

Edit: That said, I do think it'd make more sense to make the MDT as big as the 45% within the hatched zone on CSU's values.
 
CheeselandSkies said:
Both HRW WRF models suggest southeast MO into southern IL (basically St. Louis area southward to the IL-KY line) might actually have the roughest time Friday night. As an addendum to my previous, after ignoring them for a long time (mainly because they can't resolve smaller-scale supercells like the HRRR can, at least in theory), they're probably as good as any CAM.
Click to expand...

That's rather worrisome for me, as I have extended family relatives who live around the St. Louis area. I've sent texts to those whose contact information I have in an effort to let them know what could be coming their way (and to spread that information to those that they know).
 
Grand Poo Bah said:
Just to make absolute sure. Is this the same significant tornado parameter that was 12.5 for 04/27/2011, and we're seeing a 12 and 13 currently?
Click to expand...
Technically, in a way. ABC 33/40’s system software had it labeled with a proprietary name at the time as “Significant Tornado Index”. I’m not sure if it’s a 1:1 comparison though now.

Values on 4/27/11 got as high as 17.5 in central and central-western Alabama that day

Edit: @JPWX last year had a really good post I believe detailing the different ways STP can be measured
 
ColdFront said:
Technically, in a way. ABC 33/40’s system software had it labeled with a proprietary name at the time as “Significant Tornado Index”. I’m not sure if it’s a 1:1 comparison though now.

Values on 4/27/11 got as high as 17.5 in central and central-western Alabama that day

Edit: @JPWX last year had a really good post I believe detailing the different ways STP can be measured
Click to expand...
Yeah I think they're nominally the same, though I'm sure there's been subtle changes to the product over the years. I remember specifically both James and Jason Simpson mentioning on 4/27 that they didn't know the STI/STP went above 10 at the time.
 
Smokedevil said:
Spann has a 13 over Monroe county ms. Right where I'll be working Friday and Saturday.
Click to expand...
Yeah. I'm not thrilled at all. I'm gonna have to increase my wording
 
Grand Poo Bah said:
Just to make absolute sure. Is this the same significant tornado parameter that was 12.5 for 04/27/2011, and we're seeing a 12 and 13 currently?
Click to expand...
here are STP Types and VTP of 3 areas of the 2011 SO and a few other examples

Note that STPE and STPC are pretty much the same thing except for the Effective Inflow Base (pretty much if its above 0 meters from the ground it puts the STP to 0)

April 27, 2011: Philadelphia, Mississippi
STPE/STPC: 9.932
STPF: 9.914
VTP: 19.452

April 27 2011 Hackleburg
STPE/STPC: 9.546
STPF: 9.179
VTP: 11.499

April 27 2011 Tuscaloosa
STPE/STPC: 9.79
STPF: 8.575
VTP: 52.478 (WOW)

May 20 2019 Mangum
STPE/STPC: 7.658
STPF: 6.561
VTP: 3.996

El Reno EF5 May 2011
STPE/STPC: 11.49
STPF: 4.262
VTP: 11.54

Moore EF5 May 2013
STPE/STPC: 8.895
STPF: 2.988
VTP: 98.917 (WOW)

Greenfiled Tornado
STPE/STPC: 6.812
STPF: 6.441
VTP: 51.778 (WOW)

2018 July 20 Forecasted Convective Amplification Deficiency
STPE/STPC: 6.089
STPF: 4.533
VTP: 40.188

you can see that even higher STP events sometimes have Forecasted Convective Amplification Deficiency

However overall the Superoutbreak on average seems to be
STPE over 9
STPF over 9
VTP over 11
 
You must log in or register to reply here.
Back
Top