Forecast Update
Valid: Mon 27 Jul 2009 14:00 to Tue 28 Jul 2009 06:00 UTC
Issued: Sun 26 Jul 2009 21:42
Forecaster: ESTOFEX

A level 1 was issued for Eastern Spain, and for southern, eastern and central France, parts of Switzerland, southern Germany, and western Austria, mainly for severe wind gusts and large hail.


SYNOPSIS

Refer to the convective forecast...

DISCUSSION

The overall evolution of the convective activity is expected to occur more or less as foreseen earlier on. However, current thinking is that less CAPE will materialize then expected before. The resulting reduced severe weather coverage does not require a level 2 any more. However, the 09 UTC Lyon and 12 UTC Payerne soundings suggest that elevated storms will be possible rooted in a layer between 850 and 800 hPa. Steep lapse rates above that layer indicate that a large hail threat will exist.

The forecast calls for initiation of mostly elevated storms later this afternoon and in the evening across east-central France, Switzerland ans SW Germany. Large hail and a few strong downdraughts are possible, as shear should be sufficient to sustain a few supercells. Some localized excessive rainfall across the areas is also expected. As the storms move eastward during the night across southern Germany, some hail threat will probably persist, and severe winds are possible in places. But, as said, the overall coverage of the severe weather is expected to be too low to warrant a level 2.