Storm Forecast
Valid: Mon 03 Aug 2020 06:00 to Tue 04 Aug 2020 06:00 UTC
Issued: Mon 03 Aug 2020 05:25
Forecaster: VAN DER VELDE

A level 2 was issued across N Italy, Slovenia, W Croatia for large hail, tornadoes severe wind gusts and excessive rainfall.

DISCUSSION

A potent mid level trough moves across Spain, France and Benelux today, while its shortwave apex focuses on northern Italy, acquiring a negative tilt and starting a cutoff process. A classic setup for severe weather south of the Alps. A strong stationary surface low over the Po Valley will keep drawing in high low-level dewpoint air until evening, when the PV intrusion wraps around the Alps (starting in the west around 12Z). 1000-2000 J/kg MLCAPE should be present, along with 15-20 m/s 0-6 km shear increasing further at night. The combination is solid for supercells and strong multicells, which may produce large hail and severe wind gusts. The latter threat seems displaced a little to the south like Tuscany, where storm motion vectors are larger, while in the north, excessive precipitation chances are high with slower motion, continuous upslope moisture advection and high PW. Low-level shear of 10-15 m/s in the 0-1 km layer support tornadoes, also across the western Balkan. The situation is rated as level 2 with high chances of severe weather, but isolated extreme events are possible as well. The factors of SREH, DLS and CAPE are not that extreme. Cloud base heights are on the low side, which helps rain and tornado events but may reduce a bit the chances of very large hail and severe wind gusts.