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NCEP Service Center Evaluations SPC Steve Weiss
No Evaluation of Retrospective Runs
Real-Time Parallel Runs - SPC compared to operational NAM during period March 21 through April 15
- SPC focused on fundamental fields used by SPC forecasters during the preparation of severe weather outlooks, although the short-range fields in the 6-12 hour time frame can impact convective watch decisions as well. In addition to basic synoptic pattern evolution of 500 mb heights, vorticity, temperature, surface pressure and 10m winds, SPC focused on kinematic fields related to vertical shear (jet streaks/axes of maximum wind at 500 and 850 mb, bulk vertical shear in lowest 6 km, and storm-relative helicity in lowest 3 km) and thermodynamic parameters associated with instability (lowest 30 mb BL dew point, MUCAPE and MLCAPE). On most occasions, the synoptic pattern forecasts and jet structures were comparable between the operational and parallel runs, and differences between the two runs were minor from an SPC perspective.