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Severe WX Severe Risk 2/23-2/24

Currently seeing three potential issues with this system that are simply gnawing at me:

#1-Critical angle, the angle between the 0-500 meter bulk shear vector and the surface storm relative wind vector is forecast to be between 30 and 40 degrees by the majority of the models, especially when the Bunkers right motion vector is not applied to this situation (not all supercells move to the right of the mean wind in tornado events, especially in the deep south). The reason I chose to not apply Bunkers RM here is due to the fact that my gut tells me low level shear is a bit too strong for right movers based on research. Moreover, critical angles within the aforementioned range are very rarely associated with significant tornado events, and only if certain parameters are present to take up the slack.

#2-There is a significant weakness in the mid level storm relative wind structure, namely where the mean wind (non-deviant gold square on SHARPpy soundings) storm motion estimate is directly on or very near the hodograph trace for a depth of at least 4 km. This can be a strong signal for struggling mesocyclones, and if buoyancy is not high enough, some upscale growth can occur... even if just in segments/clusters that form from struggling convective cores/supercells. This weakness, existing between 2-6 km in most of the models this morning, also indicates a cessation in the veering of the storm relative wind vector with height... not good at all for fledgling mesos, because as we know, SRH was originally intended by Lilly and Dr. Davies-Jones to be a parameter for predicting the development of mid-level mesocyclones only, not low level (however there is some carry over).

#3-It's possible that high level storm relative winds are too strong for the given situation. SPC mesoanalysis currently has 80-85, even as high as 90 knot storm relative winds at anvil level moving across a large portion of the Enhanced/Moderate Risks. Our homies Rich Thompson and Dr. Rasmussen both say that's a bit too much per peer reviewed literature.

It's possible that these items are meaningless and all heck will break loose today, sure wouldn't be the first time I've blown a forecast...certainly won't be the last :)
 
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Still see more evidence of storms breaking out well ahead of the line but upper ridge trying to hang on with anticyclonic flow aloft.

500wh.us_ov.png

refcmp.us_ov.png
 
CAL said:
Currently seeing three potential issues with this system that are simply gnawing at me:

#1-Critical angle, the angle between the 0-500 meter bulk shear vector and the surface storm relative wind vector is forecast to be between 30 and 40 degrees by the majority of the models, especially when the Bunkers right motion vector is not applied to this situation (not all supercells move to the right of the mean wind in tornado events, especially in the deep south). The reason I chose to not apply Bunkers RM here is due to the fact that my gut tells me low level shear is a bit too strong for right movers based on research. Moreover, critical angles within the aforementioned range are very rarely associated with significant tornado events.

#2-There is a significant weakness in the mid level storm relative wind structure, namely where the mean wind (non-deviant gold square on SHARPpy soundings) storm motion estimate is directly on or very near the hodograph trace for a depth of at least 4 km. This can be a strong signal for struggling mesocyclones, and if buoyancy is not high enough, some upscale growth can occur... even if just in segments/clusters that form from struggling convective cores/supercells. This weakness, existing between 2-6 km in most of the models this morning, also indicates a cessation in the veering of the storm relative wind vector with height... not good at all for fledgling mesos, because as we know, SRH was originally intended by Lilly and Dr. Davies-Jones to be a parameter for predicting the development of mid-level mesocyclones only, not low level (however there is some carry over).

#3-It's possible that high level storm relative winds are too strong for the given situation. SPC mesoanalysis currently has 80-85, even as high as 90 knot storm relative winds at anvil level moving across a large portion of the Enhanced/Moderate Risks. Our homies Rich Thompson and Dr. Rasmussen both say that's a bit too much per peer reviewed literature.

It's quite possible that these items are meaningless and all heck will break loose today, sure wouldn't be the first time I've blown a forecast...certainly won't be the last :)
Click to expand...
don't feel bad... every outbreak has potential issues to look at ... even 4 27 11 .... getting bad feeling on some things also
 
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Screen Shot 2019-02-23 at 11.48.04 AM.png

This is the strongest warning from local mets (that I've seen) so far - I think they've been playing this a little conservative.

Still on the fence about what to expect here in the Memphis area; there's been cloud cover all day and rain only just stopped a couple of hours ago. Not sure if that's going to help us avoid the worst of it or if it's not even going to matter with the warm front.
 
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