Valid: Mon 10 Jun 2019 16:30 to Mon 10 Jun 2019 20:00 UTC
Issued: Mon 10 Jun 2019 16:45
This mesoscale discussion is issued to highlight enhanced potential for large to very large hail and tornadoes within isolated supercell outbreak currently ongoing in N parts of Poland.
Current dew points in the range of 17-19°C provide thermodynamic instability estimated with GFS, ICON and ECMWF on 1000-2000 J/kg. As evidenced in previous soundings from Łeba and Wrocław, a favourable clockwise-curved hodographs with 0-1km SRH exceeding 150 m2/s2 and enhanced deep layer shear >15 m/s provide conditions supportive for rotating updrafts. Thanks to the orographic lift and low-level convergence zone, around 1530 UTC explosive (as evidenced on satellite image) convective initiation took place in NW Poland. Developing thunderstorms quickly evolved into supercells capable of producing large to very large hail, severe wind and heavy precipitation. Currently we observe development of a new convective cells and better organization of ongoing supercells. It is expected that along with increasing low-level wind shear towards evening hours and lowering LCL (dew point depressions on the level of 5-6°C) tornado potential will increase, especially for isolated cells with undisturbed inflow of warm and moist airmass on their south-eastern edge.