CONVECTIVE FORECAST
VALID 06Z SUN 04/07 - 06Z MON 05/07 2004
ISSUED: 03/07 19:20Z
FORECASTER: DAHL

General thunderstorms are forecast across N-central Europe ... E-central Europe ... NE and N Europe.

General thunderstorms are forecast across E Spain.

SYNOPSIS

Broad fast zonal upper flow extending across central portions of Europe at the south periphery of large-scale N European upper low. Upper jet is expected to back somewhat during Sunday as Atlantic upper trough at the W side of the main upper low moves SE. Most of N and N-central Europe is dominated by deep polar air mass ... with high theta-e's expected to be present only over the S Balkans and the E Iberian Peninsula on Sunday.

DISCUSSION

...north-central Europe ... NE Europe ... Scandinavia...
Bulk of convective activity on Sunday should once more occur in relatively deep uncapped and weakly unstable polar air over N-central and N Europe. Deepest convective mixing will likely occur outside regions of strong shear ... but it looks that regions at the NRN fringe of the upper jet may see deep enough convection /aided by DCVA-related lift/ to benefit from about 15 to 20 m/s deep-layer shear. Expecting a few hail/wind events especially over N Germany that may isolated/briefly approach severe levels ... but weak thermodynamics and uncertainty with respect to the depth of the convective mixing preclude a SLGT ATTM.

...E Spain...
An isolated TSTM or two could develop over Spain late in the day as indicated by strengthening thermodynamic profiles and model CAPE fields/QPFs. Any storm that forms will pose a threat of brief severe wind gusts given deep/dry-adiabatically mixed sub-cloud layers. Low TSTM coverage and limited confidence that initiation will occur preclude a categorical risk ATTM.

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