Storm Forecast
Valid: Wed 04 Jun 2008 06:00 to Thu 05 Jun 2008 06:00 UTC
Issued: Tue 03 Jun 2008 21:21
Forecaster: GATZEN

SYNOPSIS

Northern Atlantic polar jet stream splits into two branches over western Europe, one surrounding a weak long-wave trough over Mediterranean, the other forming an amplified ridge over northern Europe. In the range of the ridge axis, a weak surface low over Balkans and southern/western Germany indicates the warmest air mass that is characterized by locally steep lapse rates and rather rich boundary-layer moisture. On WED, models indicate that drier and cooler air mass will spread westward over northern Germany, while moist air mass will remain further south. Some instability can also be expected in the range of rather warm air mass over the Mediterranean.

DISCUSSION

Benelux to northern Balkans

Unstable air mass is pushed to the south-west as dry air enters northern Germany. Given rather high instability and weak CIN, thunderstorms are expected along the main convergence zone where forcing will likely be sufficient for initiation during peak heating in the afternoon hours. Over some regions, stratiform rain will likely inhibit instability especially over southern Germany. Thunderstorms that form do not encounter favourable vertical wind shear, and chance for severe weather is expected to be rather low. Stronger cells will likely be accompanied be marginally severe hail and strong wind gusts. However, given complex low-level wind field, with various outflow-boundaries, wont exclude one or two short-lived organized convective cells, capable of producing isolated severe hail. Overall threat seems to be low, though.

Northern Africa

Daytime initiation over the Atlas mountains is expected as some low-level moisture develops along the northern frontal boundary of warm desert air mass. Storms stat form may evolve into supercells given strong DLS, and severe hail and severe wind gusts are forecast.

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