Yeah that cant be good.. AT ALL
CWASP from the GFS output also has a significant signal over a large area.
I've been thinking something similar may be possible. There is one potentially important difference between this one and that one though. There were actually height rises, anticyclonic flow aloft, and warm mid-level temperatures out in the open warm sector that prevented what we thought would be a major threat over north/west Alabama north of I-59 from coming to fruition. This one... there are decent height falls (rising motion), mostly straight flow aloft... but a slight cyclonic curvature from the base of the trough out into the warm sector, and mid-level temperatures are in a cooler and more acceptable range for severe weather. There theoretically should be more large scale ascent and lift with this one, although the lift still isn't overly strong.
Great point Fred … the trough on 18z loosing the positive Tilt look for sure . Trend ? I feel quite confident what I am seeing modeled today spc will put out a rather large day 3 15 percent risk at least
18z Euro is in, and it is deeper, stronger, a bit more curved with the trough, and it's not as in-your-face positive tilt.
RGEM and ICON are also more curved with the trough, and these guys were the first to trend toward what we have as the current model evolution. ICON also isn't a positive tilt by Friday late evening either, and for that matter, RGEM isn't as in-your-face with the positive tilt itself.
18z Euro still has the strong signal for renegade stuff in the open warm sector in the evening and overnight Friday well ahead of the predawn prefrontal main round, like the 12z run. 18z Euro brings that prefrontal main round in as cellular stuff though and gets it deep into central MS and north central AL going into Saturday morning...
Watching for trends...
So far, the GFS isn't less favorable than it has been, but it's still a flatter solution than the 18z stuff from above on the other models. The 00z Canadian came in solidly trending toward the 18z Euro:
18z Euro is in, and it is deeper, stronger, a bit more curved with the trough, and it's not as in-your-face positive tilt.
RGEM and ICON are also more curved with the trough, and these guys were the first to trend toward what we have as the current model evolution. ICON also isn't a positive tilt by Friday late evening either, and for that matter, RGEM isn't as in-your-face with the positive tilt itself.
18z Euro still has the strong signal for renegade stuff in the open warm sector in the evening and overnight Friday well ahead of the predawn prefrontal main round, like the 12z run. 18z Euro brings that prefrontal main round in as cellular stuff though and gets it deep into central MS and north central AL going into Saturday morning...
Watching for trends...
Very similar convective evolution signal to the 18z Euro as well on tonight's Canadian:
If the Euro tonight continues its idea from earlier, I'm going to start leaning toward the assumption that the GFS is showing it's historically known bias of being too flat and sheared with systems.
This appears to be leading to higher lapse rates Friday evening over N. Miss. and NW Al....also, the shear values are adequate in this area and something that could increase if current trends continue...I am still questioning how this all evolves late Friday evening into early Saturday. The first area of supercells that develop ahead of the front could eventually become the main squall line, or there could be a break with a seperate line forming along prefrontal trough.
www.eas.slu.edu
30% over which areas?
I say 30 percent , really would lead to enhanced risk actually which I think is the ceiling for this threat, roughly from edge of sw Tennessee across north miss. Into parts middle Tennessee catching perhaps very corner nw Alabama …
I concur
