Storm Forecast
Valid: Sat 01 Jul 2006 06:00 to Sun 02 Jul 2006 06:00 UTC
Issued: Fri 30 Jun 2006 13:56
Forecaster: DAHL

SYNOPSIS

Large upper ridge is covering the central portions of Europe ... with a series of weak vort maxima ... ejecting from SW-European/E-Atlantic longwave trough ... undercutting the ridge and crossing the W and central Mediterranean. Weak vort maxima are also present over central Europe ... which will move southward and affect SE-central Europe and the N Balkans on Saturday. Large SFC high is centered over the Baltic-Sea region ... otherwise ... rather quiescent conditions prevail.

DISCUSSION

Balkan States

Air mass over the Balkans should become quite unstable again ... with CAPEs in the 1000 to 2000 J/kg range. Locally somewhat higher values may occur where deep/rich moisture is available. Deep-layer and low-level shear are expected to continue weakening ... and severe threat should thus be somewhat limited. However ... strong CAPE should promote vigorous updrafts ... which are apt to interact with the complex orography and outflow boundaries ... and given expected large coverage of the storms ... isolated severe weather may occur. Primary mode should be weakly organized mutlicellular storms ... in which mesocyclones may be imbedded. Expect large hail and damaging winds with the strongest cells ... though an isolated tornado cannot be discouted either.

Southern Italy

Better kinematic setup should develop over southern Italy ... where 15 m/s DLS should be present in the afternoon/evening hours. MM5 also assumes increase of the low-level shear ... but main negative will be strong capping and accordingly low coverage or even complete failure of storms to initiate. Also ... latest soundings indicate lack of LL moisture ... limiting allover MLCAPE amounts. If storms develop ... main threats should be severe wind gusts and large hail.

United Kingdom

It seems that weakly unstable air mass will be advected across the UK on Saturday. LL WAA should maintain weak ascent which should help initiating isolated TSTMS in the afternoon/evening hours and through the night. Indications are that this convection will mainly be elevated ... but storms tapping BL air will benefit from 15 m/s deep shear ... and could produce marginally severe weather. Threat seems to be too low for a categorical outlook ATTM.