Potential active plains period next week...

[nickgrillo]

Seriously, no idea why people would constantly look down at this setup... Besides from the fact it's still a good 4 days out, it's been extremely consistant from run to run. Take a good look at wind fields, and you'll notice quite a few simularities between 10-9-2001 and Wednesday. Both setups had good low-level veering, and strong southwesterly flow aloft -- and had a dryline featured in the same area. There is plentiful moisture for this setup... You'll have a solid 2 days of open gulf streaming into the southern plains - as the flow becomes much more southerly by Tuesday evening.

Seriously, there is not much difference between the 10-9-2001 and this potential event... This event could either end up as a loosely organized event, or it could indeed be an outbreak. The strong flow at every level, combined with the good veering in the SFC-3km layer will yield sufficiant deep-layer shear profiles favorable for supercells. In addition, deep gulf moisture and SFC temperatures forecasted >80F should yield strong instability. Yeah, it's still 4 days out... Seriously, though, there is no reason to say why it "won't" be an outbreak, because it VERY well could (and it may not be).

 

[Mickey Ptak]

Originally posted by nickgrillo

Seriously, there is not much difference between the 10-9-2001 and this potential event...

One big difference between 10-9-01 and this system (attm) is that 10-9-01 was not a cold core setup as is with this system. The low is simple stacked and that doesn’t help the 3km directional shear IMO.

Here is some stuff on 10-9-01. What a chase day. WOW!
http://www.spc.noaa.gov/exper/archive/even...1009/index.html

Mick

 

[Mike Hollingshead]

Hmmmmm, not sure what to think of this as of the latest gfs. It isn't as stacked of a system and should have a chance at some decent directional shear. The big problem like has already been mentioned is the recycled air.

http://www.rap.ucar.edu/weather/model/disp...hr036hr156hr060

Watch the flow over the gulf. Not good.

http://www.rap.ucar.edu/weather/model/disp...hr036hr156hr060

It doesn't seem to be a TERRIBLE gulf whacking, but it doesn't look good by any stretch either. I seem to remember thinking of a similar thing Oct 9, 2001, thinking no way the juice would made it. Not only did it make it but well into c Nebraska, thanks to a very strong low level jet. I don't recall the surface pattern leading up to it though. SPC page doesn't seem to want to show the sfc and I'm too lazy to pull it up somewhere else like plymouth.

Hmmm, ok, looked just briefly. Oct 7 DFW had a TD of 45 at 21z. Then up to 61 by the 8th. That followed some decent offshore flow on the 6th. BUT, on the 5th there was low-mid 70 TDs well into S TX. I think the odds of getting the juice there was in place on Oct 9th is less just looking at prog'd sfc winds. But, there seems to be some chance out there worth hoping for.

http://www.rap.ucar.edu/weather/model/disp...ours=hr132hr156

http://www.spc.noaa.gov/exper/archive/even...9/250-oa-00.gif

Those 2 are a good deal different though. Lets just hope for less gulf whacking and less cuttoffness and we might be in luck.

 

[brody_clifton]

I also dislike the current cutoff nature ther GFS is showing - from the 108 to 156 hour at 300mb, the initial closed upper low gets more and more cutoff from the polar jet, and continues to weaken as it slowly moves east from CA.
GFS has the polar jet staying way up in Canada.
From a quick browse at the October events for OK on the SPC's 'Severe Thunderstorm Events' page, the events shown all seem to be associated with a western conus dip in the polar jet stream. I want to search some more on the SPC Events site for examples of closed upper low days and see if any have ever led to outbreaks, currently am not sure, but I'd guess the storms would not be as good as with a fast moving shortwave under a strong longwave 250mb trough.

 

[nickgrillo]

The GFS has slowed down the progression of the trough, by around 12 hours or so. A dryline develops over the western TX panhandle on Wednesday, with the GFS initiating precip ahead of the dryline by 0z Thursday. I'd have to think the 36hrs of forecasted southerly flow should be able to advect in deep gulf moisture. The low is much less stacked, and there is pretty decent veering in the 0-3km layer - and speed shear is good at pretty much every level. There should be enough moisture to get things going, with widespread >60 Td's progged to advect into the panhandle warm sector.

A few more hours until the new 0z runs (whistles the theme to Jeopardy) :lol: