Jump to content
  • Member Statistics

    17,586
    Total Members
    7,904
    Most Online
    LopezElliana
    Newest Member
    LopezElliana
    Joined

TS Fay - Drought ending Rains and Severe Convection


weatherwiz
 Share

Recommended Posts

3 minutes ago, weatherwiz said:

Kinda looking harder and I'm not so sure there really is a "tornado threat" with this...first off the probability was rather low but I think it's even low enough to where it's not even worth a mention. But I'm not seeing much in the way to support directional wind shear with this...or certainly not enough to cause rotation. I know with tropical systems the land/ocean interaction can aid in this potential but given how cold the SST's are I think we'll see a pretty stable layer develop off-shore. The greatest potential for convection would be pretty far inland but I think in this case any instability is only going to enhance precipitation rates...with such poor lapse rates and deep/moist column it might be tough to generate lightning...not that this is needed for TOR potential as with these setups in about the lowest few km but the lowest few km don't really look impressive. 

BOX begs to differ 

Additionally, we
can`t rule out a few isolated severe thunderstorms which could spawn
an isolated tornado. Low level wind fields are quite favorable for
strong rotation (0-1 km shear >25 kts and 0-1 km storm relative
helicity >150 m2s2).
Link to comment
Share on other sites

The higher helicity I think is more of a product of the stronger llvl flow rather than turning of the winds in the lower levels. However, storm moving may be slightly angled compared to the mean flow so that could certainly enhance rotation potential. Regardless, I don't think instability in the lowest lvls is going to be sufficient enough. 

Link to comment
Share on other sites

9 minutes ago, STILL N OF PIKE said:

I would “Guess” This would be more than 1-2” where the core of rain passes 

Isn’t iso-tornado about as strong a language as we see in SNE 

No tornado “outbreak “ ? Follows the trend of zero outbreaks in 200 years here

 

Yep this probably won’t be hurricane  Agnes with regard to tornadoes 

Link to comment
Share on other sites

20 minutes ago, Bostonseminole said:

looks like center is trying to reform further east, recon headed out there so data soon.

Yea and that’s what the 12z NAM indicated . Granted it’s the nam, but that’s all of the 12z suite we have at the moment. Latest vis does seem to show the convection-less swirl being abandoned for the deep convection east of OBX.

Link to comment
Share on other sites

37 minutes ago, STILL N OF PIKE said:

I would “Guess” This would be more than 1-2” where the core of rain passes 

Isn’t iso-tornado about as strong a language as we see in SNE 

No tornado “outbreak “ ? Follows the trend of zero outbreaks in 200 years here

 

1. No not really

2. We've had our share of tornado outbreaks 

Link to comment
Share on other sites

1 hour ago, weatherwiz said:

Kinda looking harder and I'm not so sure there really is a "tornado threat" with this...first off the probability was rather low but I think it's even low enough to where it's not even worth a mention. But I'm not seeing much in the way to support directional wind shear with this...or certainly not enough to cause rotation. I know with tropical systems the land/ocean interaction can aid in this potential but given how cold the SST's are I think we'll see a pretty stable layer develop off-shore. The greatest potential for convection would be pretty far inland but I think in this case any instability is only going to enhance precipitation rates...with such poor lapse rates and deep/moist column it might be tough to generate lightning...not that this is needed for TOR potential as with these setups in about the lowest few km but the lowest few km don't really look impressive. 

mm, I'm not sure the type of torsional mechanics that twist columns in land falling/land interacting TCs is the same as that which is supplied by the typical shearing structures that you're using there, though. 

With TCs, what happens is the flow moves from a relative low impeded region, over land where there is an abrupt increase in frictional induced boundary-layer drag; the air must by conservation bend inwards toward lower pressure more so in the 0-3km layer, which instantiates positive shear ... more sub-geostrophic inward, causing a hooked updrafts in the lower 3-km, while the overriding air in the unimpeded 700 mb level is defaulted to increasing bulk shear; a different aspect than suspending a parcel through a vertical column where there's potential vorticity due to bulk shear aspects, synoptically.  That's not likely to be modeled well because by convention/state of tech ...models don't resolve that lower layer very well

Link to comment
Share on other sites

2 minutes ago, Typhoon Tip said:

mm, I'm not sure the type of torsional mechanics that twist columns in land falling/land interacting TCs is the same as that which is supplied by the typical shearing structures that you're using there, though. 

With TCs, what happens is the flow moves from a relative low impeded region, over land where there is an abrupt increase in frictional induced boundary-layer drag; the air must by conservation bend inwards toward lower pressure more so in the 0-3km layer, which instantiates positive shear ... more sub-geostrophic inward, causing a hooked updrafts in the lower 3-km; a different aspect than suspending a parcel through a vertical column where there's potential vorticity due to bulk shear aspects/synoptics.  That's not likely to be modeled well because by convention/state of tech ...models don't resolve that layer very well

I appreciate this information here. I've never fully understood this process with TCs (and can say I've never tried to explore learning...not sure why). My weakest knowledge in this field lies within tropical weather. This though provided a great visual in my head of the physics/processes here and I actually understand much better. Thank you.

Link to comment
Share on other sites

1 minute ago, weatherwiz said:

I appreciate this information here. I've never fully understood this process with TCs (and can say I've never tried to explore learning...not sure why). My weakest knowledge in this field lies within tropical weather. This though provided a great visual in my head of the physics/processes here and I actually understand much better. Thank you.

yeah... we had two course in tropical up at UML as per curr.  

Link to comment
Share on other sites

5 minutes ago, WxWatcher007 said:

Yeah that Mid level vortex has had some staying power and now it looks like a LLC is developing per visible. Might be an interesting flight. 

Probably a minimal  tropical storm when it gets up here but sure is looking good now

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...