Severe WX Severe Weather Threat 11/5-11/7

[NWMSGuy]

West. Middle tenn. northern ms. North half ala... look ominous

I would think portions of East AR are also in play.

 

[Fred Gossage]

GFS is definitely faster than last night's run that got everyone's attention too. Last night's run had the surface low back near SGF with the cold front on the AR/OK line at 6Z Tuesday. This 12Z run has the surface low in western IL with the cold front coming through Jonesboro, AR at 6Z Tuesday.

 

[tennessee storm chaser]

I would think portions of East AR are also in play.

Yes... very could b before noonish that area Monday

 

[mdberry]

GFS is definitely faster than last night's run that got everyone's attention too. Last night's run had the surface low back near SGF with the cold front on the AR/OK line at 6Z Tuesday. This 12Z run has the surface low in western IL with the cold front coming through Jonesboro, AR at 6Z Tuesday.

Fred,

I know that we are several days out from this event; but if things line up the way they are looking now; could you see the SPC going with a High Risk somewhere over North Alabama, North Mississippi, or Southern Tennessee?

 

[Fred Gossage]

Yes... very could b before noonish that area Monday

It would definitely extend into the early evening in eastern Arkansas, even with the idea of faster timing...

 

[Xenesthis]

Fred,

I know that we are several days out from this event; but if things line up the way they are looking now; could you see the SPC going with a High Risk somewhere over North Alabama, North Mississippi, or Southern Tennessee?

I am curious to your thoughts on this as well Fred..

 

[Fred Gossage]

Fred,

I know that we are several days out from this event; but if things line up the way they are looking now; could you see the SPC going with a High Risk somewhere over North Alabama, North Mississippi, or Southern Tennessee?

I think it's less impossible than it is with most systems we talk about here, and I think just getting the timing for Alabama out of that "straddle zone" between what SPC uses for "Monday" and "Tuesday" and fit the timing firmly into "Monday" for them, alone, would increase the chances of that happening. That "straddle" is the only reason why Alabama is not sitting in the 30% risk already. They made it clear in the discussion that the *significant* risk would extend into Tuesday (and Tuesday to them starts at 12Z Tuesday).

 

[mdberry]

I think it's less impossible than it is with most systems we talk about here, and I think just getting the timing for Alabama out of that "straddle zone" between what SPC uses for "Monday" and "Tuesday" and fit the timing firmly into "Monday" for them, alone, would increase the chances of that happening. That "straddle" is the only reason why Alabama is not sitting in the 30% risk already. They made it clear in the discussion that the *significant* risk would extend into Tuesday (and Tuesday to them starts at 12Z Tuesday).

Thanks Fred...always appreciate your insight

 

[Xenesthis]

Fred, I am in southern Middle TN.. do you feel the risk is as high here as in AL?

 

[Fred Gossage]

Fred, I am in southern Middle TN.. do you feel the risk is as high here as in AL?

Once you account for usual model thermodynamic biases and look at how they performed with the low-level thermos with just the last system... and how this pattern is much more favorable for a potent air mass to come northward... yes. I honestly think the strong tornado threat extends northward toward the Ohio Valley... with the greatest threat probably between I-40 and U.S. 80 (JAN-MGM).

 

[Richardjacks]

Does anyone have the 500mb chart from Nov.10 2002? I was trying to find one but couldn't.

 

[warneagle]

Does anyone have the 500mb chart from Nov.10 2002? I was trying to find one but couldn't.

I found this:

 

[CAL]

 

[Fred Gossage]

View attachment 924

Thank you for this! I've been needing a clean 500mb chart of that event without the reanalysis error over the GOM for many years.

 

[CAL]

No problem! If you need any more just holler.

 

[Richardjacks]

The trough for this event is a little sharper compared to 2002.

 

[Xenesthis]

The trough for this event is a little sharper compared to 2002.

So what effect might that have?

 

[Fred Gossage]

So what effect might that have?

Stronger wind fields, stronger pressure falls, the potential for the surface low to be closer (the sfc low with that event actually moved into southern Canada that morning and we just had pressure falls down the cold front to back the low-level winds).....

 

[Richardjacks]

Stronger wind fields, stronger pressure falls, the potential for the surface low to be closer (the sfc low with that event actually moved into southern Canada that morning and we just had pressure falls down the cold front to back the low-level winds).....

Also you could argue that it could be slightly colder aloft...but there could be other unknown variables to compensate.

 

[Xenesthis]

Also you could argue that it could be slightly colder aloft...but there could be other unknown variables to compensate.

So basically it’s making possibly more volitile