Storm Forecast
Valid: Wed 05 Aug 2020 06:00 to Thu 06 Aug 2020 06:00 UTC
Issued: Tue 04 Aug 2020 19:59
Forecaster: PUCIK

A level 1 was issued for a belt from northern Greece towards southern Hungary mainly for excessive rainfall and to the lesser degree for large hail and severe wind gusts.

SYNOPSIS and DISCUSSION

Compared to the previous forecast period, severe weather threat will shift southeastward, in conjuction with the movement of an upper tropospheric cyclone. As of 06 UTC, the cyclone will be centered over central Italy and will shift towards the Ionian Sea by Thursday morning. On its forward flank, moist and warm airmass will be in place in weak easterly low-level flow. NWP models simulate MLCAPE between 500 and 1500 J/kg, increasing towards south. 0-6 km bulk shear will reach 10 - 20 m/s, allowing for well organised multicells and perhaps several transient supercells. Overall evolution of the situation may be heavily influenced by the overnight convection.

The highest severe weather threat will exist over northern Greece, Northern Macedonia and southern Serbia, where models simulate the best overlap of CAPE and shear. At the same time, several rounds of storms will be possible over the area, enhancing the threat of heavy rainfall. It is possible that an MCS will form in the afternoon to evening hours and move towards northwest. If supercells manage to form, isolated large hail will also be possible. Severe wind gust threat will be confined to the southern part of Level 1, where cloud bases will be higher and shear stronger.

Isolated to scattered storms are also forecast over northern and eastern Scandinavia, underneath a plume of steep midtropospheric lapse rates associated with an mid-tropospheric low.