Storm Forecast
Valid: Thu 14 May 2026 06:00 to Fri 15 May 2026 06:00 UTC
Issued: Wed 13 May 2026 21:24
Forecaster: PUCIK
A level 2 was issued across N Italy mainly for large to very large hail, severe wind gusts and tornadoes
A level 1 was issued across the E Adriatic coastline mainly for heavy rainfall and to a lesser degree for severe wind gusts and tornadoes
A level 1 was issued for Sardinia and central Italy mainly for heavy rainfall and to a lesser degree for severe wind gusts and tornadoes.
A level 2 was issued for central Turkey for damaging wind gusts and large hail.
A level 1 was issued for Turkey mainly for severe wind gusts, heavy rainfall and large hail.
A level 1 was issued for southern Russia mainly for large hail.
A level 1 was issued for northwestern Russia mainly for heavy rainfall.
DISCUSSION
... N Italy ...
Q-vectors suggest that synoptic-scale lift, associated with an approaching trough, will overspread the area in the late morning to afternoon hours. Towards the surface, a well-defined convergence zone is forecast by all the models to run from the Apennine foothills towards Veneto region. Cyclogenesis is forecast along this zone and mesoscale lift will be provided by either this convergence or local orography. Further cyclogenesis and convergence is anticipated to develop over Lombardy in the late afternoon hours. Airmass around the convergence zones will be characterized by modest low-level moisture with specific humidity between 8 and 10 g/kg and 7 to 7.5 K/km lapse rates, yielding MLCAPE values of 500 to 1000 J/kg. Conditions will deteriorate towards northeast and anywhere south of the Apennnine convergence zone.
The first storms will fire on the Apennine convergence zone probably already by 12 UTC. Combination of intense 0-6 km bulk shear up to 30 m/s and 0-3 km shear up to 20 m/s with isolated storm formation will favour supercells. Right-moving supercells will track through the belt of enhanced CAPE and thus will be strongly favoured. Supercells will move fast with very strong inflow and will be capable of large to very large hail and damaging wind gusts. Hail size should not reach considerably above 5 cm given limited CAPE above -10 deg C isotherm and modest moisture content. High res models point to locally enhanced low-level shear near the convergence zone and tornadoes will be possible.
The second round of storms will form over the Lombardian convergence zone later in the afternoon. Here, splitting storms should be more prominent with right-movers being favoured as the hodograph curvature increases towards the night. Supercells will be capable of large hail, severe wind gusts and later on also tornadoes as the 0-500 km SRH locally exceeds 100 m2/s2.
Questionable area remains Friuli Venezia Giulia and Istria, where favourable shear profiles, especially near the ground are simulated by the models owing to the warm air advection ahead of the deepening low. Concerning Istria, relatively dry airmass near the LFC may preclude sustained storms and their initiation, while it is questionable whether surface-based storms will form over FVG. In case that surface-based supercells form or reach these areas, expect a tornado risk besides large hail and severe wind gust risks. Overall, only minor changes to the level outlines have been done compared to the extended outlook.
... western Sardinia and central Italy ...
Aforementioned trough will also affect this area in the evening to early night hours. No frontal boundary or major convergence zone is simulated by the models. Thus, orography along the coastlines will need to provide the mesoscale lift. Scattered storms are forecast to form, rapidly progressing inland in mean wind around 20 m/s. Profiles over both areas show skinny CAPE mostly confined to the warm part of the cloud, yielding conditional heavy rainfall threat should cells repeatedly develop in one location. If surface-based storms can form, there will be a risk of isolated severe wind gusts or a tornado given strong low-level shear.
... The eastern Adriatic coastline ...
An increase in storm coverage is expected from the evening into overnight hours, associated with short-wave trough approach and synoptic-scale lift overspread the area. With no pronounced frontal boundary, coastal orography will be the initiation mechanism with storms moving fast from favourable into unfavourable area. It is possible that initiation will be anchored over the local terrain, resulting in local heavy rainfall risk. This scenario seems more likely according to the ICON-D2 in the mountains near Rijeka. A local tornado or severe wind event will also be possible with strong-low level shear, especially with the first wave of the storms. Shear will decrease as the trough crosses the area.
... Turkey ...
A fast-moving short-wave trough and a cold front will cross Turkey during the day. First storms will be ongoing across W Turkey already in the morning hours with threats of heavy rainfall given saturated profiles. As storms progress towards east, cloud bases will increase with more diurnal heating. MLCAPE around 1000 J/kg is forecast in the interior Turkey with steep low-level lapse rates. Given fast movement of the cold front and mean cell motion comparable to the cold front speed, a fast upscale growth into a squall line seems likely. Given favourable environment for strong downdrafts due to Inverted-V profiles and moderate 0-6 km bulk shear between 15 and 20 m/s, central part of Turkey may experience more widespread severe wind risk. Large hail threat will be present too if supercells manage to form ahead of the advancing squall line and the Black Sea coastline will see the highest risk of heavy rainfall. Compared to the extended outlook, a Level 2 was added for part of Turkey and a Level 1 was extended further east and southeast.
... SE Russia ...
A couple of well-organised storms given 15 to 20 m/s bulk shear may move over the lowlands from mountains and produce large hail.
... N Russia ...
Slow moving storms moving parallel to a cold front in moist environment may result in a local heavy rainfall event.
