Storm Forecast
Valid: Sun 19 Jul 2026 06:00 to Mon 20 Jul 2026 06:00 UTC
Issued: Sat 18 Jul 2026 21:04
Forecaster: PUCIK
A level 1 was issued across E Spain and Pyrenees for a possibility of a storm with large to very large hail and severe wind gusts.
A level 2 was issued over Apennines for large to very large hail and severe wind gusts.
A level 2 was issued in a belt from Slovenia to W Serbia mainly for large to very large hail, severe wind gusts and to the lesser extent for heavy rainfall.
A level 2 was issued over S - central Poland mainly for large to very large hail, damaging wind gusts and to the lesser extent for heavy raifnall.
A level 1 was issued from S Germany through Czechia, Austria to Slovakia and Poland mainly for severe wind gusts and large hail.
A level 1 was issued from Romania to Ukraien mainly for heavy rainfall, large hail and to the lesser degree severe wind gusts.
DISCUSSION
... Eastern Spain and Pyrenees ...
Convective initiation is more likely over Pyrenees, but still not guaranteed. If storms form, they would initiate in the environment of around 1000 J/kg of MLCAPE and up to 25 m/s of 0-6 km bulk shear. Expect large to very large hail and severe wind gusts in case a sustained storm forms and achieves supercell stage. Even more impressive environment is simulated further south, with extremely high MLCAPE values, reaching 4000 J/kg. Strong vertical wind shear is forecast here as well. Any sustained storm forming on a local dryline in such environment could be capable of very large to giant hail and destructive wind gusts. However, the likelihood of initiation is quite low as forming updrafts will quickly move towards high CIN environment towards the coastline. Nevertheless, decided to mark this region with Lvl 1 as it deserves attention.
... S Germany, central to N Austria, Czechia, Slovakia, Poland ...
A fast-moving cold front along with a short-wave trough will sweep across the region. Lack of strong convergence signals on the front suggest rather spotty, isolated lift along the front. An exception may be Poland, where pronounced Q-vector convergence at 850 hPa is simulated along with a deepening surface low. Isolated to scattered storms will form along the whole front and local orography, moving E and NE. Storm coverage may be the greatest over Poland with the strongest anticipated mesoscale lift. Squall line formation (with attendant severe weather risk) will be the highest here. 500 to 1000 J/kg of MLCAPE is forecast along and ahead of the front, increasing eastwards towards the regions with more abundant surface heating. 0-6 km bulk shear will reach 15 to 20 m/s across majority of the region with shear increasing towards the Alps, where lower CAPE is simulated over S Germany. The best overlap of CAPE and shear is forecast across S-central Poland, where a Lvl 2 was introduced. Here, a chance will exist for supercell to produce very large hail. Otherwise, whole area has a mixed risk of severe wind gusts and large hail with a mix of transient supercells and small linear segments traveling E-wards.
... S Austria, Croatia, Slovenia, Croatia, Bosnia, Serbia ...
A cold front will surge south along the eastern rim of the Alps, providing strong linear lift and initiating storms that will spread S and SE in the afternoon and evening hours. 1000 to 2500 J/kg of MUCAPE are forecast within the area, overlapping with unidirectional 15 to 25 m/s of 0-6 km bulk shear. Current thinking is that several supercells will initiate along the front and local orography and move SE-wards with threats of large to perhaps very large hail and severe wind gusts. Chances for growth into linear segment will be there along the front itself and the northern part of the Lvl 2, though storms moving E will be undercut by cold air advection. Conditions for a longer-lived convective windstorm are thus questionable, unless a linear segment manages to propagate more towards south.
... Apennines ...
A decent chance will exist for a SE-moving supercell along the orographic dryline in impressive CAPE-shear environment. Any sustained supercell in this environment with up to 3000 J/kg of MLCAPE and 30 m/s of 0-6 km bulk shear would be capable of very large to giant hail and damaging wind gusts. It is expected that one to two storms will manage to form here, so the coverage will remain isolated. The highest threat will lie in Bologna to Rimini belt. While it is not certain that a storm develops, combination of moderate probability of initiation along with very high conditional probability of severe weather given that storm suceeds to form results in Lvl 2 probabilities.
... NE Italy ...
Some SE-moving supercells may form over the southern flank of the Alps and progress towards the Adriatic coastline with threats of large hail and isolated severe wind gusts. Compared to the previous day, lower and skinny CAPE will limit the possibility of very large hail. Storm activity may be in several waves starting in the afternoon with some chance of a supercell going over the Adriatic Sea even during the night.
... Romania to Ukraine ...
Storms will form over the Carpathians in scattered to widespread coverage. The outflow boundaries will then spread towards Ukraine, initiating further storms over the lowlands. 0-6 km bulk shear between 13 and 18 m/s is forecast with some orographic modifications possible. Well organised multicells and transient supercells are expected with threats of large hail and heavy rainfall. Rather moist profiles with low LCLs may reduce the downburst risk to some degree, but huge precipitation loading can be expected, especially in supercells and thus severe wind gusts will be possible too.
