3/27/08 NOW: OK

[cedwards]

The storm in Muscogee county has a nice hook and couplet on it. It is now tornado warned. I suspect that it is being undercut by the front. I have been watching the towers going up from my back yard. I have a little timelapse of the towers early on.

 

[Kevin Rider]

According to the Weather Channel a tornado has been reported 1 mile north of Council Hill

 

[Michael O'Keeffe]

Two tornado warned cells in Missouri. One in in Pulaski county has a MAJOR hook on it and a nice couplet just north of Lebanon. Hail also up to baseballs are possible according to the warning text. The other is near St. James, MO north of Rolla which also has a nice flying eagle shape to it. Dewpoints aren't great in this area so very surprised to this going on, but we are talking about SW Missouri lol.

 

[Michael O'Keeffe]

Confirmed "dangerous tornado" near Council Hill, OK! Only moving at 20mph. This is so crazy!! I hate when this happens. I hope this doesn't head toward any towns because it sounds like a mean storm.

 

[Rebecca Robinson]

Looks like Fort Smith,Ak is going to be hit very shortly by the Muskogee Cell.
Got a beautiful flying eagle in Dent Co with a huge hail core.

 

[Jim Zandonai]

Those cells in MO. were showing high reflectivity too..a composite shot showed a 77 south of Eagle Springs recently with VILs in the 65+ area..this with consistent rotation in many cells showing hooks..Spring is in force there with 30s in north and 70s south in MO.

 

[Rebecca Robinson]

Looks like the three cells in Dent, Texas and Crawford are about to merge.
Correction: last radar loop shows they have merged.

Anyone look at Ottawa co in NE OK? Last loop there was nothing there and proof is almost at warning level.

 

[Kenny Drake]

I'm trying to figure out why we didn't get a squall line almost instantly upon initiation. My current theory is that there was a sweet balance between the CAP and the amount of dynamic forcing ahead of the cold front. In Missouri a meso-low being picked up on sfc obs definitely had a lot to do with added low-level helicity. Regardless, i'm trying to figure out why the SPC/NWS offices have not gone with tornado watches when it was obvious they should have (this isn't the first time this spring.) If I see great shearing with height and the potential for the CAP to be busted I'm going tornado watch whether it verifies or not. A false alarm is one thing, but a miss is a complete different story.

 

[Jeff Snyder]

I'm trying to figure out why we didn't get a squall line almost instantly upon initiation. My current theory is that there was a sweet balance between the CAP and the amount of dynamic forcing ahead of the cold front. In Missouri a meso-low being picked up on sfc obs definitely had a lot to do with added low-level helicity. Regardless, i'm trying to figure out why the SPC/NWS offices have not gone with tornado watches when it was obvious they should have (this isn't the first time this spring.) If I see great shearing with height and the potential for the CAP to be busted I'm going tornado watch whether it verifies or not. A false alarm is one thing, but a miss is a complete different story.

The "shape" of this frontal zone isn't much different than that from Monday of last week (in northern TX, a front that undercut all warm-sector storms). However, I think the weaker and more veered mid-level flow in this case may be aiding the discrete mode. Instead of the storms being moved beyond the surface cold front (i.e. rearward relative to the front), the cells today are able to stay ahead of the cold front long enough for vertical perturbation pressure gradients to become established, and long enough for said forcing to turn the cells to the right. If the mid-level flow were to be more backed and/or stronger, the storms may have been advected to the northeast more quickly, and they may have ended up being undercut by the front. In addition, flow near the equilibrium level is quite a bit weaker than 3-17-08, so there may be less significant seeding occuring. This is starting to veer into a DISC (more post-storm) type, so I'll stop here.

Oh yeah, forecast and analyzed instability from far NE OK into MO was relatively marginal. The 00z SGF sounding show significantly more CAPE than forecast, but that's a bit of hindsight. Given that we should see some near-surface stabilization soon, I'm not sure it would have been prudent for the SPC to replace a recently issued SVR box with a new Tor box if the tornado thread isn't expected to persist more than a couple of hours. Current RUC analysis shows very significant surface-based CINH and relatively meager sbCAPE. So, between the time the 00z SGF sounding came in and the time the current supercell will lose their surface-based "feed" may not be more than a couple of hours. The tornado threat didn't really look significant enough to warrant a Tor box, IMO.

FWIW, the SVR box did have 20% prob of "2 or more tornadoes", so the SPC did address the possibility of one or two tornadoes (in the probs and in a mesoscale discussion issue to discuss the status of the watch).

 

[Rich Thompson]

FWIW, the SVR box did have 20% prob of "2 or more tornadoes", so the SPC did address the possibility of one or two tornadoes (in the probs and in a mesoscale discussion issue to discuss the status of the watch).

That's exactly why we include probabilistic information with our forecasts - to express the uncertainty. I don't think 4 tornadoes and many more TOR warnings were the specific expectation today, but that doesn't mean that tornadoes were ruled out.

The possibility of supercells suggests a non-zero tornado threat. Supercells were mentioned in the text discussion of the first SVR TSTM watch, but I don't think you'd be that happy with everything becoming a TOR watch based on small probabilities.

Rich T.

p.s. The multi-year average is for 20% of SVR TSTM watches to verify with 2+ tornadoes.

 

[Bill Tabor]

FWIW, the SVR box did have 20% prob of "2 or more tornadoes", so the SPC did address the possibility of one or two tornadoes (in the probs and in a mesoscale discussion issue to discuss the status of the watch).

This comment may be more DISC:

Yeah as I understand it, the nature of the severe weather has to show an environment somewhat conducive and likely to form tornadoes in order to justify a Torn box. Otherwise severe and let NWS make the call on the warnings as they occur. If the environment changes or enough reasonable torns / torn warnings are produced then can upgrade to a Tornado box - assuming as Jeff mentions the situation will remain favorable to production of possible tornadoes.