Jump to content
  • Member Statistics

    17,608
    Total Members
    7,904
    Most Online
    Vesuvius
    Newest Member
    Vesuvius
    Joined

April 1st-4th Severe Weather Thread


andyhb

Recommended Posts

  • Replies 608
  • Created
  • Last Reply

Starting to see some things that may me believe tomorrow may surprise us.  Earlier today I had discounted the tornado threat and believed it was primarily just a hail threat.  But now the tornado threat seems to be kicking up just a bit.  Helicity values are high, shear is reasonable, soundings are looking fairly impressive.  

 

Not sold on the NAM yet, I think the GFS has a better handle.

If moisture return is ample and the system is a bit stronger than anticipated we could see the threat amplify a bit.  Thursday could be interesting for the Tulsa metro, especially if the dryline winds up a bit west of current model predictions.

Link to comment
Share on other sites

The GFS is bad news, scattered discrete convection up and down the dry line by 0z. Even further west this run.

Really deepens the sfc low in the afternoon. 65 dews along dryline.

Yeah, for as scary as the NAM is, the GFS is even scarier.  Just as much instability and the winds are more backed at the sfc.

Link to comment
Share on other sites

Yeah, for as scary as the NAM is, the GFS is even scarier.  Just as much instability and the winds are more backed at the sfc.

I'd argue that the GFS even might be a touch low on the instability especially in coverage, which isn't surprising.

Link to comment
Share on other sites

I'm new here and just follow you all to stay informed and learn but why is everyone's post time way off? Also, I live in NW OKC/Edmond...tomorrow looking bad bad or just stay aware?

 

Check your settings to make sure your time zone is set correctly. Just click on your username on the top of the page and go to My Settings. 

Link to comment
Share on other sites

00Z NSSL WRF absolutely nailed timing and location of CI today in TX. The new 00Z run is coming in, so I am curious to see what it has. Tomorrow definitely has some ugly potential as does Thursday.

 

It also completely nailed 5/19 last year (Carney/Shawnee) down to the actual location of the storms.

 

Another thing, correct me if I'm wrong but the convergence and ascent today wasn't as strong as it is forecast to be tomorrow, and we did get CI (especially the convergence along the dryline with strongly backing surface winds forecast).

Link to comment
Share on other sites

This forecast for tomorrow is the devil for anyone in the OKC area, given how high the potential is if storms do fire and the inconsistencies with the models.

 

It's kind of frightening knowing that this could be a nowcast event where significant tornadoes might not have a whole lot of preparation time in advance, considering that appears very likely if the dryline does light up.

Link to comment
Share on other sites

None of the high-res models I've seen (NCEP'S NMM and ARW, EMC WRF, NSSL WRF, 4-km NAM) pop the dryline tomorrow.  However, the GFS, 12-km NAM, and Euro all do.  This is the reverse of what I'm used to and, honestly, I'm at a bit of a loss as to explain why.

 

Any ideas at all?  You're usually pretty damn spot on so I'd be very interested if you had any thoughts on that.  The hi-res models seem to have been performing rather well in recent times so I would think some weight has to be given to them. 

Link to comment
Share on other sites

None of the high-res models I've seen (NCEP'S NMM and ARW, EMC WRF, NSSL WRF, 4-km NAM) pop the dryline tomorrow.  However, the GFS, 12-km NAM, and Euro all do.  This is the reverse of what I'm used to and, honestly, I'm at a bit of a loss as to explain why.

 

Agreed. Very reminiscent of 4/14/12 in terms of an extremely volatile environment and negligible CINH by late afternoon, but many models showing no CI. However, that was a much more potent trough than this one. It's anybody's guess until noon tomorrow. One of the oddest setups I can remember in OK in terms of such high potential, but so little confidence in initiation. The 5% tor probs seem like an appropriate compromise between the significant likelihood of a cap bust and the 10-15% hatched that would be warranted if we knew sustained convection would evolve.

 

EDIT: I see the 00z ECMWF isn't screwing around with weak or short-lived convective signals... explosive development at the triple point that goes bonkers between 21z-03z. Tornado potential would be high.

Link to comment
Share on other sites

Agreed. Very reminiscent of 4/14/12 in terms of an extremely volatile environment and negligible CINH by late afternoon, but many models showing no CI. However, that was a much more potent trough than this one. It's anybody's guess until noon tomorrow. One of the oddest setups I can remember in OK in terms of such high potential, but so little confidence in initiation. The 5% tor probs seem like an appropriate compromise between the significant likelihood of a cap bust and the 10-15% hatched that would be warranted if we knew sustained convection would evolve.

 

EDIT: I see the 00z ECMWF isn't screwing around... explosive development at the triple point that goes bonkers between 21z-03z. Tornado potential would be high.

I don't see any good reason why there shouldn't be isolated initiation by late afternoon/early evening before the dryline begins retreating again.  CINH should be minimal, OK won't be under any large or small-scale ridge axis, and there should be plenty of convergence along the dryline while it progresses E, especially near the triple point.  It may only be one supercell, but I just don't know why nothing should form tomorrow.  I see no distinct reason.

Link to comment
Share on other sites

None of the high-res models I've seen (NCEP'S NMM and ARW, EMC WRF, NSSL WRF, 4-km NAM) pop the dryline tomorrow.  However, the GFS, 12-km NAM, and Euro all do.  This is the reverse of what I'm used to and, honestly, I'm at a bit of a loss as to explain why.

As does the 10 km Canadian RDPS. 

 

And I agree, very rare where you see the convective allowing models and parameterized guidance in completely different camps. 

post-999-0-83489000-1396423205_thumb.gif

Link to comment
Share on other sites

As does the 10 km Canadian RDPS. 

 

And I agree, very rare where you see the convective allowing models and parameterized guidance in completely different camps. 

 

Just an observation, on that 05z RAP, (valid at 23z Wed) when you get east of I-35, you get an area between 850-700mb w/ pretty uniform temperature. This doesn't translate to a ton of -CINH, if you're looking at that map. But if you get a little closer to the dry line, you get something more like this, which is a nicer ride for our theoretical parcel friend...

 

Is there enough speed shear to sustain an updraft, or will the updrafts in that environment be strong enough to sustain themselves, if they can get going?

post-9012-0-80546100-1396423708_thumb.pn

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...