Jesse Risley
Staff member
Two plays today within the broader southwest flow aloft, as the main upper low works into the lower Great Basin region, and this is progged to push into the four corners region by late today. Further west, it looks like a potent H5 perturbation will begin to overspread the Rockies and eastern Piedmont regions by late afternoon. Looking at a current morning surface map, moisture is pooling into the upslope regions, longitudinally, across the Colorado Piedmont and Sand Hills region. The usual zone of vorticity and convergence should initiate storms across NE CO and SE WY by mid to late afternoon. It should be noted that some models have been depicting moisture mixing out at the lower levels. Nevertheless, ample shear and moisture should exist to support some robust updrafts as storms work ENE into W NE. Progged soundings do show favorable LCLs, MLCAPE profiles and marginal streamwise vorticity to facilitate a few supercells with a tornado or two not out of the question; storms in the southern portion of the area of greatest risk, namely NE CO and far SW NE, will have the more favorable proximity to the better mid-level flow. In addition, favorable looking CAPE values within the -10 to -30° C layer and formidable 700-500 mb lapse rates would suggest there will be some higher end severe hail reports too.
Of greater concern is the low pressure system in eastern IA and warm front progged to extent ESE into NC IL and IN. Ongoing convection will likely have an impact on the eventual placement of the warm front, and residual OFBs will be exist across the region as well. The atmosphere is forecast to destabilize by late afternoon, as storms should initial in the warm sector across MO and E IA and propagate eastward in N IL. Discrete supercells appear to initially be the dominant storm mode, and all modes of SVR weather are possible, including a heightened risk of tornadoes where storms are able to interact with the surface warm front or residual boundaries, given very magnanimous 0-1 km SRH profiles around 200-300 m2/s2 and amble instability parameters. PW values are quite large, which lead to some concerns with the evolution of HP supercells, given SR anvil level winds, and visibility issues. With time, convection looks to morph into more of a QLCS mode as storms gyrate eastward towards SW MI, N IN and eventually NW OH, where wind damage and embedded mesovortices become the dominant threats. I would expect a few strong tornado reports are likely today with initial discrete convection, assuming storms are able to interact and maintain themselves commensurate with residual boundaries and/or the surface warm front, and also assuming that adequate destablization materializes in the wake of earlier convective activity approaching from the WSW.
Of greater concern is the low pressure system in eastern IA and warm front progged to extent ESE into NC IL and IN. Ongoing convection will likely have an impact on the eventual placement of the warm front, and residual OFBs will be exist across the region as well. The atmosphere is forecast to destabilize by late afternoon, as storms should initial in the warm sector across MO and E IA and propagate eastward in N IL. Discrete supercells appear to initially be the dominant storm mode, and all modes of SVR weather are possible, including a heightened risk of tornadoes where storms are able to interact with the surface warm front or residual boundaries, given very magnanimous 0-1 km SRH profiles around 200-300 m2/s2 and amble instability parameters. PW values are quite large, which lead to some concerns with the evolution of HP supercells, given SR anvil level winds, and visibility issues. With time, convection looks to morph into more of a QLCS mode as storms gyrate eastward towards SW MI, N IN and eventually NW OH, where wind damage and embedded mesovortices become the dominant threats. I would expect a few strong tornado reports are likely today with initial discrete convection, assuming storms are able to interact and maintain themselves commensurate with residual boundaries and/or the surface warm front, and also assuming that adequate destablization materializes in the wake of earlier convective activity approaching from the WSW.
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