Bill Schintler
EF4
Chase target:
8 miles south of Storm Lake, IA.
Timing and storm mode:
Storms will initiate at 4 PM CDT, with a multicell clusters the primary mode. Supercells will also be possible along the southern periphery of the complex, with all forms of severe weather possible there. As was the case today, the storms will evolve into a large MCS and race east-southeast through IA, with wind the primary threat.
Synopsis:
Ridging will gradually build in the WRN CONUS while flow becomes increasingly NWRLY over the upper Midwest and the NERN CONUS trough amplifies. A lead S/WV will dive through MN and WI on Sunday, with a second impulse following in its wake over the ND/SD border. H5 flow will increase to 50-60kts within these streaks. At the SFC, a diffuse CF will extend along the NY/PA border with a low centered near BUF at 00 Z. Further west, the position is less certain due to location of numerous OFBs. By 00Z, this boundary should bisect IA from SE to NW, and then further W it will extend along the NEB/SD border.
Discussion:
FCST is a particular challenge due to the ongoing MCS in IA and resulting location of residual boundaries and degree of air mass recovery. Probably the best target location will be in NWRN IA along the outflow-enhanced baroclinc zone. Once again, storms should develop late in the afternoon, with a multicell mode dominating. Embedded supercells will be likely along the leading edge of the storm complex. Storms should again develop into a large complex and track E and SE through IA. Skies should remain mostly clear S of the boundary, allowing for strong insolation with MLCAPES AOA 3000J/kg beneath steep mid-level lapse rates of 8-8.5 C/km. Although the target area will be S of the strongest H5 flow, SFC-6km shear should exceed 50 kts. Hodograph curvatures will also increase as a 20kt LLJ strengthens to and veers to the SW.
- bill
10:30 PM CDT, 07/19/08
8 miles south of Storm Lake, IA.
Timing and storm mode:
Storms will initiate at 4 PM CDT, with a multicell clusters the primary mode. Supercells will also be possible along the southern periphery of the complex, with all forms of severe weather possible there. As was the case today, the storms will evolve into a large MCS and race east-southeast through IA, with wind the primary threat.
Synopsis:
Ridging will gradually build in the WRN CONUS while flow becomes increasingly NWRLY over the upper Midwest and the NERN CONUS trough amplifies. A lead S/WV will dive through MN and WI on Sunday, with a second impulse following in its wake over the ND/SD border. H5 flow will increase to 50-60kts within these streaks. At the SFC, a diffuse CF will extend along the NY/PA border with a low centered near BUF at 00 Z. Further west, the position is less certain due to location of numerous OFBs. By 00Z, this boundary should bisect IA from SE to NW, and then further W it will extend along the NEB/SD border.
Discussion:
FCST is a particular challenge due to the ongoing MCS in IA and resulting location of residual boundaries and degree of air mass recovery. Probably the best target location will be in NWRN IA along the outflow-enhanced baroclinc zone. Once again, storms should develop late in the afternoon, with a multicell mode dominating. Embedded supercells will be likely along the leading edge of the storm complex. Storms should again develop into a large complex and track E and SE through IA. Skies should remain mostly clear S of the boundary, allowing for strong insolation with MLCAPES AOA 3000J/kg beneath steep mid-level lapse rates of 8-8.5 C/km. Although the target area will be S of the strongest H5 flow, SFC-6km shear should exceed 50 kts. Hodograph curvatures will also increase as a 20kt LLJ strengthens to and veers to the SW.
- bill
10:30 PM CDT, 07/19/08
