Storm Forecast
Valid: Sat 06 May 2006 06:00 to Sun 07 May 2006 06:00 UTC
Issued: Fri 05 May 2006 21:51
Forecaster: DAHL

SYNOPSIS

Omega-line upper flow pattern is present over Europe and the eastern Atlantic ... with two large upper lows over SE Europe and the E Atlantic respectively ... and an upper high over Scandinavia ... which supports large-scale SFC high covering N and NE Europe ... as well as NW Russia. Weak and small SFC low-pressure centers persist over SE and SW Europe. Plume of moist and weakly unstable air mass is present over Spain and France ... and will be focus for convective development on Saturday.

Discussion

France ... Spain
MLCAPEs of about 500 J/kg should be possible with SFC heating in the afternoon hours. Large-scale forcing for ascent is expected to remain fairly weak ... but mesoscale ascent should be provided by outflow boundaries of Friday's convection ... by orographic features and along the frontal boundaries stretching across E and W France/Spain, respectively. A few cells may favorably interact with one another or with outflow boundaries laid out by earlier convection and may briefly become organized ... posing a threat for wind/hail approaching severe levels ... but allover organized threat should be rather low given minimal kinematic and weak thermodynamic support.

North Balkans
Ahead of small vort max at the inner periphery of the SE European upper low... scattered rather shallow TSTMS should form. Given presence of a rather deep CBL ... strong downdrafts producing gusty SFC winds may accompany the storms ... but allover minimal CAPE/shear preclude organized severe TSTM threat. Isolated lightning may also occur farther S and E of the TSTM area ... but indications are that bulk of activity will be tied to the small vort max.