CONVECTIVE FORECAST
VALID Sun 10 Jul 06:00 - Mon 11 Jul 06:00 2005 (UTC)
ISSUED: 09 Jul 17:42 (UTC)
FORECASTER: DAHL

SYNOPSIS

Upper low over the NRN Mediterranean ... will make little EWD progress during the period ... though peripheral vort maxima are expected to deform/elongate the large-scale low somewhat. Building upper high is progged to spread across NW Europe ... being centered over the British Isles by Monday 06Z. At the SFC ... dominating feature is strengthening high-pressure area over the British Isles ... otherwise ... pressure distribution is rather flat though several small/weak low-pressure centers are expected to exist E and S of the mediterranean upper low.

DISCUSSION

...central Mediterranean...
As rather vigorous vort max overspreads the region at the periphery of the large-scale upper low late in the day ... supporting 25 to 35 m/s 500 hPa flow ... some potential for severe evolution may exist provided that sufficient CAPE will be in place. Current indications are that mainly rather cool/dry air will be forced to ascent ahead of the vort max ... and that convective threat is thus limited. This is supported by the modest numerical QPFs. Late in the night/early Monday morning ... unstable air mass farther S may be tapped though ... and a few severe TSTMS could develop. These could be capable of producing large hail ... damaging wind gusts and maybe a tornado or two given diurnally-enhanced low-level shear.

...central Europe...
Weakly-capped and weakly unstable air mass should be present across central Europe. TSTMS should initiate towards early afternoon and may become rather widespread. Though deep shear will be marginal with about 15 m/s ... ample low-level flow is expected to develop ... which may support a few rotating updrafts with an attendant hail/tornado threat. Also ... local flash flooding may occur. Altogether ... severe threat seems to be too low for a SLGT though an upgrade may be considered with later outlooks.

...E Spain...
Inverted-V profiles coupled with about 20 m/s deep shear should exist over central Spain and may be supportive of a few high-based downburst-producing TSTMS. Coverage should be rather low ... and a SLGT does not appear to be necessary ATTM. Somewhat cooler but more moist BL air is expected to be present along the Mediterranean coast. Though this may boost the CAPEs ... CINH should also be quite high in this environment ... and initiation is expected only after the low-level moisture has been mixed out with associated decrease of CAPE.

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