Storm Forecast
Valid: Wed 13 May 2026 06:00 to Thu 14 May 2026 06:00 UTC
Issued: Tue 12 May 2026 16:02
Forecaster: TUSCHY

Numerous level 1 areas were issued for S-CNTRL into SE Europe mainly for hail and gusts with a low-end coastal tornado risk over CNTRL/S Italy.

A level 1 was issued for parts of Benelux into W-CNTRL Germany for isolated hail and gusts.

SYNOPSIS

We're in the recharging process of the persistent negative geopotential height anomaly atop N-CNTRL to CNTRL Europe. A new trough approaches from the NW and settels down over CNTRL Europe with a new burst of cool air from the NW. This trough gets framed by blocking anticyclones over the NE Atlantic and N Africa. Another deepening trough affects SE Europe, whereas a quasi-stationary positive tilted trough still impacts the Iberian Peninsula and the offshore areas to the SW.

Frontal-wise we still deal with a wavy and slowly eastward shifting boundary over NE into E Europe with more fronts moving in from NW to CNTRL Europe. In addition, geopotential heights/surface pressure lowers over N Italy during the forecast with an evolving diffuse lee vortex.

DISCUSSION

... CNTRL Italy towards Albania ...

Morning convection occurs over far NW Italy and Corse/Sardegna with isolated severe possible (e.g. heavy rain and a coastal tornado event). Rapid weakening during the morning precludes a level 1 upgrade.


A passing trough advects cool mid-levels towards the level 1 area, where seasonable moisture from the Mediterranean resides. The net result will be 400-800 J/kg weakly capped MUCAPE with lowering values onshore due to shrinking BL moisture. A confined CAPE/shear overlap exists with long/straight hodographs and up to 15-20 m/s DLS. Organized multicells and a few supercells (e.g. deviating updrafts near the coasts) bring strong to severe gusts and hail in the 2-4 cm range (hail size hampered by thin CAPE profiles and lowered EL heights). An isolated coastal tornado event is possible. This convection clusters betimes while shifting E/SE. We expanded the level 1 into W Albania to account for adequate onshore moisture advection for a lingering severe risk as convection moves ashore.

A similar risk exists in the level 1 over parts of NE Greece, where a belt of 300-600 J/kg MUCAPE overlaps with decent shear for a few multicells with hail and gusts.

... Turkey to the Greater Caucasus ...

A diffluent and cyclonic SW-erly mid/upper flow regime atop modest low to mid-tropospheric moisture assist in 400-800 J/kg MUCAPE with regional higher peaks (e.g. E of the Greater Caucasus with better moisture trajectories off the NE Caspian Sea). Scattered thunderstorm occur and modest DLS in the 10 m/s range should keep the severe risk in check. Regionally enhanced shear e.g. by tropographic influence can result in a few focused spots with augmented severe like E of the Greater Caucasus. An upgrade was performed, where CAPE exceeds 1000 J/kg, which includes parts of Georgia, Armenia and Azerbaijan, but also a region just E of Georgia (into Russia) and far N into E-CNTRL Turkey. The main risk will be hail and gusts.

... Benelux to W-CNTRL Germany ...

Placed along the S fringe of the southward dropping trough, a brisk W-erly mid-level flow regime affects the area of interest. Meager moister keeps MUCAPE in the 200 to locally 400 J/kg range, whereas shear offers impressive values including long and slightly curved hodographs. A few thunderstorms could become strong to severe in case of cell merging or line-ups normal to the 30 kt+ 0-3 km shear vector with some hail and strong gusts forecast. In nowcasting one has to monitor the trend of some models which show a passing short wave and better defined moisture flux convergence over W-CNTRL Germany. If this trend verifies we could see a more focused line of thunderstorms with a growing strong gust risk. In addition an isolated tornado cannot be ruled out but this risk is modulated by the mesoscale. A confined and low-end level 1 was added for a combined low-end gust, hail and tornado risk.

... E-Europe ...

A plume of modest CAPE spreads N ahead of the wavy frontal boundary. Shear is modest at best so most of the activity should stay sub-severe with local graupel/gust and heavy rain. A temporarily better organized line may emerge from NE Belarus NE into Russia, where cold pool driven gusts can evolve for a few hours. This risk is too marginal for a broad level 1 area however.