CONVECTIVE FORECAST - UPDATE
VALID 15Z THU 08/07 - 06Z FRI 09/07 2004
ISSUED: 08/07 14:44Z
FORECASTER: GROENEMEIJER

There is a moderate risk of severe thunderstorms forecast across parts of Germany, eastern France and Benelux, the western Czech Republic and western Poland, the western Alps and northern Italy

There is a slight risk of severe thunderstorms forecast across an area surrounding the moderate risk area including entire Austria, Benelux and Czech republic and greater parts of France, Poland and Italy.

General thunderstorms are forecast across refer to convective forecast

SYNOPSIS

refer to convective forecast

DISCUSSION

...Germany, Benelux, eastern France, western Czech Republic, western Poland ...
Update: Complex flow pattern creates considerable unceratinty w.r.t. the evoltuion of convective systems during the remainder of the forecast period. Quite steep low level lapse rates and 500 - 1000 J/kg have been realised south of an area of precipitation over northern Germany. Supercells over Switzerland and southwestern Germany are expected to increase in coverage and move northeastward. The storms have a threat of producing large hail and damaging winds as well as a few tornadoes. The storms may merge into a bow echo system capable of producing widespread damaging winds.

In the left exit region of the southwesterly jet over western Germany, a few storms including supercells have formed over the southeastern Netherlands. These storms will likely persist and move into northwestern Germany, posing a threat of hail, winds and perhaps a few tornadoes as well.

...Italy...
Update Very strong shear profiles are present over northern Italy where 500 - 1000 J/kg and locally more MLCAPE is forming this afternoon per 12Z radiosonde observations. Widespread convective development is expected during the next few hours. Supercells capable of producing hail, storng winds and tornadoes are expected. The storms may cluster in a severe MCS over this area as well.

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