CONVECTIVE FORECAST
VALID 06Z MON 19/04 - 06Z TUE 20/04 2004
ISSUED: 19/04 01:22Z
FORECASTER: GROENEMEIJER

General thunderstorms are forecast across the southern and western British Isles, west-central Europe, the north-central Mediterranean, the Alpine countries, the western Balkans and parts of central Europe.

SYNOPSIS

Monday at 06Z....the dominating feature at mid- and upper levels is a strong west-northwesterly jet streak is moving into the western Mediterranean. A cold front is located over the northwestern Mediterranean and rapidly moving eastward reaching the western Balkans Tuesday at 06Z. During the second half of the forecast period...a stable baroclinic wave is expected to move into southern France.

DISCUSSION

...southern France, Catalonia...
Behind the cold front, marginal instability is expected to form in response to diurnal heating. Given the quite strongly sheared environment, a few low-topped supercells may form, but storm coverage will likely be quite limited because of a lack of large-scale rising motions over the area. Chances of tornadoes will be relatively low as there will not be much low-level moisture so that the LCL height will consequently be rather high. There is a chance of some marginally severe hail and wind reports. At the end of the day, stabilisation is expected as warm advection associated with the baroclinic wave affects the area.

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