"upper cold lows" . "Upper tropospheric cyclonic vortex" . . "upper tropospheric trough cell" . . "tropical upper tropospheric cyclones" . . "upper-level trough" . . "upper-level low" . "Upper tropospheric cyclonic vortex" . . "tropical upper tropospheric low" . "mid to upper-tropospheric low" . "TUTT cell" . "upper tropospheric cyclonic vortex" . "upper air cyclonic circulation" . .