Jump to content
  • Member Statistics

    17,584
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

Possible late season severe outbreak morning of 10/8/14


CoastalWx

Recommended Posts

Because some are expecting widespread EF3s and derechos. It's not gonna happen like that.

 

Its been so quiet for so long, that when some see you and Ryan, et all get excited, it can make it seem like a bigger deal than what actually may transpire.  But like all SVR set-ups, who really knows?  You could get nothing but some elevated thunder, or there are two touchdowns tomorrow morning with a bunch of wind damage reports.  Neither out-come would be too surprising, but its hard to go out and just make a definitive call about what to "expect" one way or another.

Link to comment
Share on other sites

  • Replies 550
  • Created
  • Last Reply

Interesting handling between the mesoscale models.

Was just about to mention that MCV-looking thing. Looks like the center approaches KTOL at 5 a.m.

The 18z 4km NAM, on the other hand, punches a dry"slot" through between 4-6 a.m. before two clusters/lines of semi-discrete cells blow up around daybreak. One targets western Mass. and the other moves from NE Conn. into eastern Mass.

Right exactly the time I go out for last training run before marathon on Saturday. Last run ever ?
Link to comment
Share on other sites

Certainly an interesting setup. May be a neat case study after its done. I'm not sure how often we'll see this sort of setup play out during the pre-dawn hours in October. Could be junky or there could even be a few significant severe reports. 

Link to comment
Share on other sites

Its been so quiet for so long, that when some see you and Ryan, et all get excited, it can make it seem like a bigger deal than what actually may transpire. But like all SVR set-ups, who really knows? You could get nothing but some elevated thunder, or there are two touchdowns tomorrow morning with a bunch of wind damage reports. Neither out-come would be too surprising, but its hard to go out and just make a definitive call about what to "expect" one way or another.

In the context of October it's a real good setup. The point here is that it could almost all wind reports too. Who knows, but unless the models way overestimate CAPE....I'm intrigued by the setup. To me , instability is the main key here.

Link to comment
Share on other sites

18Z Nam shifted Sig tor, supercell composites south of SNE with only a portion of the Cape under supercell risk.

 

Yeah I mentioned why before. It develops quite a min of low level theta-e aorund 9z in the wake of the first round of convection. Probably a spurious feature and something that looks more robust since you're looking at 3 hour panels.

Link to comment
Share on other sites

Yeah I mentioned why before. It develops quite a min of low level theta-e aorund 9z in the wake of the first round of convection. Probably a spurious feature and something that looks more robust since you're looking at 3 hour panels.

It had it 12z run too. It does seem a bit weird.

Link to comment
Share on other sites

Was just looking at some soundings from the 15z SREF and 19z RAP and WOW.  Both models show some pretty solid cape values in the 0-3km and 0-6km layers and shear values virtually between 30 and 35 m/s.  Helicity values too are in the 200-250 m2/s2.  This is pretty substantial stuff.  I think OceanSt mentioned this a little earlier but not only are we looking at a tornado possibility but you have to think a sig. tor is possible as well.  You really hate to use wording THAT strong but those ingredients would warrant that possibility.  

 

It's also interesting to note, however, the RAP is much less impressive with instability back west across central CT...it seems like it may be a bit too low with dewpoints back this way so that could be why.  Also, on a more interesting note, the RAP has VERY steep mid-level lapse rates move in, actually on order of 7-7.5 C/KM.  

Link to comment
Share on other sites

Was just looking at some soundings from the 15z SREF and 19z RAP and WOW.  Both models show some pretty solid cape values in the 0-3km and 0-6km layers and shear values virtually between 30 and 35 m/s.  Helicity values too are in the 200-250 m2/s2.  This is pretty substantial stuff.  I think OceanSt mentioned this a little earlier but not only are we looking at a tornado possibility but you have to think a sig. tor is possible as well.  You really hate to use wording THAT strong but those ingredients would warrant that possibility.  

 

It's also interesting to note, however, the RAP is much less impressive with instability back west across central CT...it seems like it may be a bit too low with dewpoints back this way so that could be why.  Also, on a more interesting note, the RAP has VERY steep mid-level lapse rates move in, actually on order of 7-7.5 C/KM.  

Steep lapse rates, no cap, wind direction somewhat out of the south,low lcl's, good trigger. Correct me if I'm wrong but this seems more organized linear or segments to me (not excluding a poss spot tor involved) and maybe a spot discrete cell if someone is lucky?

Link to comment
Share on other sites

Hopefully  all the TOR's down in KY and Tn today are an indication of what transpires downstream..

 

i haven't looked at conditions down there..are they as favorable as they are from NJ to S  Maine?

On paper it's a similar setup. High shear/low CAPE.

Link to comment
Share on other sites

What we want to look for when looking at model data is whether or not we are seeing run-to-run consistency and/or model agreement.  We have started to see some wobbling occur within the guidance and that suggests that models aren't having a good handle on this situation.  There is alot occurring right now as we speak (such as a maturing sfc low) and if the models are initializing and are off on one thing it's going to be off with the evolution of what it's depicting.  

 

We have yet to really see the sfc low develop yet, or at least if it has it's still very weak.  However, we are seeing a sow increase in the llvl wind fields regardless and we have 60F dews already up to at least the south coast.  Once a stronger southerly flow becomes established we should have no problem advecting these values further inland.   

 

We could honestly get a better handle of the situation ourselves just by watching trends within the mesoanalysis data and watch how the sfc low evolves and watch the surge of theta-e air begin to work in.  

Link to comment
Share on other sites

Steep lapse rates, no cap, wind direction somewhat out of the south,low lcl's, good trigger. Correct me if I'm wrong but this seems more organized linear or segments to me (not excluding a poss spot tor involved) and maybe a spot discrete cell if someone is lucky?

 

The activity will likely initiate as discrete, however, this will probably occur either down in NJ or somewhere just off the coast.  the wind fields are aligned and the storm mode looks to favor activity quickly concealing to a QLCS in which you would have embedded mesos.  Out ahead of the QLCS there will likely be some discrete cells as well which at some point would get swallowed up by the line I would think.  

 

We could also see a scenario in which we see a cluster of storms which act as if they are discrete..what I mean by that is you have a bunch of cells which are closely packed, however, you can distinguish each individual cell.  Something like this is a bit more rare, however, it can't be ruled out at this time, at least until we have a better handle on the exact storm mode.  

 

In this case, if we wanted numerous discrete cells I would think we would like to see turning up through the entire troposphere...the turning really goes from the sfc up through about 850mb (SE to SW) but from here on up it's all unidirectional shear.  If we had SE at the sfc to S at 925, SW at 850, WSW at 700mb and W or NW at 500mb that would favor numerous discrete, even without much in the way of capping.  Actually...this might make what I stated in the scenario above more likely.  

Link to comment
Share on other sites

Was just looking at some soundings from the 15z SREF and 19z RAP and WOW. Both models show some pretty solid cape values in the 0-3km and 0-6km layers and shear values virtually between 30 and 35 m/s. Helicity values too are in the 200-250 m2/s2. This is pretty substantial stuff. I think OceanSt mentioned this a little earlier but not only are we looking at a tornado possibility but you have to think a sig. tor is possible as well. You really hate to use wording THAT strong but those ingredients would warrant that possibility.

It's also interesting to note, however, the RAP is much less impressive with instability back west across central CT...it seems like it may be a bit too low with dewpoints back this way so that could be why. Also, on a more interesting note, the RAP has VERY steep mid-level lapse rates move in, actually on order of 7-7.5 C/KM.

If something spins up, 0-1km shear argues it will be like Revere not some EF0 twisting a couple trees down.

Steep lapse rates, no cap, wind direction somewhat out of the south,low lcl's, good trigger. Correct me if I'm wrong but this seems more organized linear or segments to me (not excluding a poss spot tor involved) and maybe a spot discrete cell if someone is lucky?

Shear mainly parallel to forcing would likely yield linear segments. However, there is enough low level helicity to result in brief supercellular structures.

Link to comment
Share on other sites

18z NAM bufkit soundings are absolutely ridiculous...was looking at PYM and I can't believe what I'm seeing.  Between 6:00 and 9:00 AM it has over 1000 SBcape and just over 600 0-6km cape and just over 200 0-3km cape.  Helicity just over 250 and shear of 35 m/s...and actually as high as 40 m/s...those values are jaw dropping.  

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...