...The Netherlands, NW-Germany...
A deep, conditionally unstable layer is present at mid-levels, providing a loaded-gun configuration as 1500-2000 J/kg MLCAPE will likely build below a capping layer during the day. Along a surface warm front across the Nrn/NErn Netherlands and NWrn Germany, low-level convergence might trigger a few thunderstorms. At this point, we think that convection will not develop before early evening, when CIN should be minimal. Across the North Sea, an area of 30+ m/s deep-layer shear should be present, with the 20 m/s contour lying across the Nrn Netherlands towards Berlin. Of particular interest is a high-shear zone at low levels with its maximum across the Srn North Sea, extending across the Nrn Netherlands. Here, 0-1 km shear could reach 10-15 m/s, which should enhance rotation within convective updrafts. If thunderstorms form, they could become supercellular. Regardless of convective mode, WBZ heights of about 3 km AGL should be low enough to enable large hail to reach the surface, especially within supercells. Given the amount of latent instability and relatively dry air at mid-levels, convective wind gusts of >25 m/s should also be possible with any thunderstorm. Owing to quasi-linear upward forcing along the warm front, storms might cluster at nightfall and even merge into an MCS. With this scenario, severe wind gusts would become the main threat. Considering our uncertainty with respect to the amount of CIN and upward forcing, a SLGT is issued for the time being.
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