Storm Forecast
Valid: Mon 26 May 2025 06:00 to Tue 27 May 2025 06:00 UTC
Issued: Sun 25 May 2025 21:20
Forecaster: PUCIK
A level 2 was issued across NW to central-N Turkey mainly for damaging wind gusts, large to very large hail, tornadoes and heavy rainfall.
A level 1 was issued across W Turkey mainly for large hail and heavy rainfall.
A level 1 was issued across central-S Turkey mainly for large hail and severe wind gusts.
A level 1 was issued across Romania to Moldova mainly for heavy rainfall.
A level 1 was issued across Ukraine mainly for heavy rainfall and tornadoes.
A level 1 was issued across W Russia mainly for tornadoes.
A level 1 was issued across N Italy mainly for large hail and heavy rainfall.
DISCUSSION
... Turkey ...
A regional outbreak of severe thunderstorms is likely over parts of western and central Turkey. Ahead of a pronounced low at mid to upper troposphere, a cold front will advance across the region. Combination of ample surface heating inland and advection of moister airmass ahead of the front will yield MLCAPE values from 500 to 1000 J/kg inland and up to 2000 J/kg along the N Turkey coastline. Widespread storms are forecast to initiate along the front and move towards the Black Sea. Ahead of the front isolated to scattered storms will initiate over the local orography.
Well-organised storms are forecast within the Lvl 2 with 0-6 km bulk shear of around 25 and 0-3 km shear around 20 m/s. Near the front, widespread initiation and strong 0-3 km shear will result in several linear segments, likely forming bow echoes. As the storm development spreads east towards the well heated areas inland with deep boundary layer and inverted-V profiles, strong cold pools are forecast. This combined with strong shear will result in high threat of damaging wind gusts, including isolated gusts of 30+ m/s.
East of the front, more isolated initiation will yield several supercells with large hail and severe wind threat. As the supercells progress towards the Black Sea coastline with higher CAPE, threat of very large hail will increase correspondingly. Low LCL and enhanced low-level shear environment near the coastline will also elevate the tornado threat. To the west of the advancing front, elevated storms may train over the same areas, bringing heavy rainfall.
... Romania to Ukraine ...
From Romania to Moldova, strong synoptic-scale lift is forecat, giving rise to a large stratiform rain shield. Embedded convection is forecast given presence of marginal MUCAPE in the profiles, enhancing the rainfall rates. Lightning activity will be either minimal or completely absent.
Over Ukraine, there is high uncertainty whether surface based storms will form. If yes, there will be some tornado and severe wind threat given strong low-level shear. If not, storms will remain embedded in the stratiform rainshield, locally enhancing the rain threat.
... N Italy ...
Isolated to scattered storms are forecast to form over the mountains at first. Towards the evening and night, models indicate a development of low-level convergence zone over the area, providing enough lift for the storms over the lowerlands. With 0-6 bulk shear up to 15 m/s, some well-organised storms, including transient supercells, will be possible with threat of large hail. As the coverage of storms increases towards the night and mean flow decreases, heavy rainfall threat will be enhanced.
... W Russia ...
ECMWF shows some low-level CAPE developing on the cold front with embedded storms within a stratiform rainshield. Strong low-level wind field will yield 0-1 km shear exceeding 10 m/s, often combined 0-1 km SRH exceeding 100 m2/s2. In case surface-based storms develop in the setup, tornadoes may occur. However, GFS and ICON-EU are more sceptical concerning CAPE, so the introduced Lvl 1 is highly uncertain at the moment.
