Skip Talbot
EF5
Very volatile setup depicted on both the NAM and GFS. A deepening surface low is forecast over western/central KS, with a warm front draped across southern NE and a dryline down through central KS. A shallow trough, but with a strong impulse looks to bring 50-70 knots of 500 mb flow across the triple point located along the KS/NE border. There is also a very impressive southerly low level jet forecast over the warm sector with 40-50 knots at 850 mb.
Parameters are all there for huge supercells and significant severe weather: dewpoints in the mid to upper 60's, approaching 70 F to the east in se NE/ne KS bring forecast MLCAPE values to 3000 J/kg or more. Shear profiles are the most impressive, however: effective shear values just north of the warm front are an exceptional 90 knots. Effective storm relative helicity also exceptional with values well over 500 m2/s2 on and north of the warm front. Surface to 1km shear of 40+ knots, also extreme. Severe parameters are all extreme along the warm front where the hodographs are huge and curving.
Cap looks to be a significant player on this setup. 700 mb temps are a toasty 16-18 C in the Kansas warm sector. Significant CINH and LSI values are depicted in the warm sector, down the dryline in KS, and right on the surface low over central NE. Capping is less of an issue to the east along the MO river and extreme se NE/ne KS at the edge of the EML and where moisture is greater. Current lid strength values would suggest to me that the convective initiation will be suppressed down the dryline in Kansas or result in mainly elevated supercells.
The warm front looks like the serious player on this setup, perhaps in a similar fashion to May 11. I would expect storms to initiate near the warm front/dryline triple point by early to mid afternoon where low level lapse rates are steepest and with the enhanced lift along these boundaries. Like May 11, if storms go up right on the warm front, which they may be forced to do due to the strong warm sector capping, I would expect a quick transition to HP mode, due to the large amount of instability yet very low LCLs (600-1000 m immediately north of the warm front). Huge ground scraping, tornadic supercell. These storms are difficult to chase and very dangerous, so chasers should be on their guard, and constantly conscious of their escape routes and situational awareness.
Given the the hot temps and capping, I'd expect an initially high based storm to fire somewhere in extreme southern NE or northern KS off the nose of the low, and for it to track along the warm front in southeast NE. If the EML tapers off a bit more to the south, northeast KS may also be in play, but this target looks largely capped at the moment. Secondary targets might be southern IA, where the warm front is uncapped, and there is significant midlevel flow already in place by mid afternoon. This target may have issues with airmass recovery from earlier convection though. Another secondary target might be ne CO/sw NE where the moisture wraps around the low.
Primary concern with this setup is storm mode. We might have some training HPs supercells which are dangerous to chase due to concerns with visibility, flash flooding, and the large damaging circulations and RFD they produce. There might also be some issues with convection north of the warm front with the open cap and strong flow in place.
Parameters are all there for huge supercells and significant severe weather: dewpoints in the mid to upper 60's, approaching 70 F to the east in se NE/ne KS bring forecast MLCAPE values to 3000 J/kg or more. Shear profiles are the most impressive, however: effective shear values just north of the warm front are an exceptional 90 knots. Effective storm relative helicity also exceptional with values well over 500 m2/s2 on and north of the warm front. Surface to 1km shear of 40+ knots, also extreme. Severe parameters are all extreme along the warm front where the hodographs are huge and curving.
Cap looks to be a significant player on this setup. 700 mb temps are a toasty 16-18 C in the Kansas warm sector. Significant CINH and LSI values are depicted in the warm sector, down the dryline in KS, and right on the surface low over central NE. Capping is less of an issue to the east along the MO river and extreme se NE/ne KS at the edge of the EML and where moisture is greater. Current lid strength values would suggest to me that the convective initiation will be suppressed down the dryline in Kansas or result in mainly elevated supercells.
The warm front looks like the serious player on this setup, perhaps in a similar fashion to May 11. I would expect storms to initiate near the warm front/dryline triple point by early to mid afternoon where low level lapse rates are steepest and with the enhanced lift along these boundaries. Like May 11, if storms go up right on the warm front, which they may be forced to do due to the strong warm sector capping, I would expect a quick transition to HP mode, due to the large amount of instability yet very low LCLs (600-1000 m immediately north of the warm front). Huge ground scraping, tornadic supercell. These storms are difficult to chase and very dangerous, so chasers should be on their guard, and constantly conscious of their escape routes and situational awareness.
Given the the hot temps and capping, I'd expect an initially high based storm to fire somewhere in extreme southern NE or northern KS off the nose of the low, and for it to track along the warm front in southeast NE. If the EML tapers off a bit more to the south, northeast KS may also be in play, but this target looks largely capped at the moment. Secondary targets might be southern IA, where the warm front is uncapped, and there is significant midlevel flow already in place by mid afternoon. This target may have issues with airmass recovery from earlier convection though. Another secondary target might be ne CO/sw NE where the moisture wraps around the low.
Primary concern with this setup is storm mode. We might have some training HPs supercells which are dangerous to chase due to concerns with visibility, flash flooding, and the large damaging circulations and RFD they produce. There might also be some issues with convection north of the warm front with the open cap and strong flow in place.