Radar Analysis - 14 June 1998
The Scenario:
- A severe thunderstorm watch for central
and eastern Missouri expired at 400 AM CDT.
- Our staffing was lowered from 5 to 3 staff members (fair weather staffing).
- It is Sunday morning. Two convective lines, each around 120 km in length, form northwest
of St. Louis between 430 - 530 AM CDT.
- The convective line farthest away from the KLSX merges with the leading convective line.
- What do you think happens during the following 2 hours?
Fig. 1. Plan view of KLSX WSR-88D reflectivity image at 0.5° slice for 1030 UTC (full 230 km).
Fig. 2. Plan views of WSR-88D reflectivity / storm-relative velocity images at 0.5°/2.4° slice respectively for 1045 UTC.
- The convective line farthest away merges with the leading convective line between 1040 and 1156 UTC.
- The MARC velocity signature was difficult to detect with this case. We have discovered that the MARC velocity signature is not easily identifiable with nocturnal severe convection.
Fig. 3. Tracks of MARC across east-central Missouri.
Fig. 4. Time-height series plot of Mid-Altitude Radial Convergence (#2)
Fig. 5. Plan view of WSR-88D reflectivity image at 0.5° slice for 1056 UTC.
Fig. 6. Plan views of WSR-88D reflectivity / storm-relative velocity images at 0.5° for 1100 UTC.
Fig. 6. Four panel presentation of WSR-88D reflectivity / storm-relative velocity image for the lowest two elevation slices (0.5° / 1.5°) at 1100 UTC.
Fig. 7. Six panel presentation of WSR-88D reflectivity / storm-relative velocity image for the lowest three elevations slices (0.5° / 1.5° / 2.4°) at 1106 UTC.
Fig. 8. Plan view of WSR-88D reflectivity image at 0.5° slice for 1130 UTC.
Fig. 9. Six panel presentation of WSR-88D reflectivity / storm-relative velocity image for elevation slices (1.5° / 2.4° / 3.4°) at 1130 UTC.
Fig. 10. Circulation tracks across east-central Missouri for 14 June 1998. Time of initial circulation detection is depicted in UTC and denoted by marker specific to each circulation track every 5 minutes.
Fig. 11. Time-height series plot of rotational velocities (Vr; m/s) of Circulation #1.
Fig. 12. Time-height series plot of Circulation #1's diameter versus time.
Fig. 13. Time-height series plot of rotational velocities (Vr; m/s) of Circulation #2.
Fig. 14. Time-height series plot of Circulation #2's diameter versus time.
Fig. 15. Plan view of WSR-88D reflectivity image at 0.5° for 1200 UTC.
