Storm Forecast
Valid: Mon 05 Jun 2006 06:00 to Tue 06 Jun 2006 06:00 UTC
Issued: Sun 04 Jun 2006 16:02
Forecaster: TUSCHY

SYNOPSIS

Omega-like streamline pattern continues for most parts of Europe, although the western trough ( over the eastern Atlantic Ocean ) will start a cut-off process during the next 24 hours...Unseasonable strong upper-level trough continues to affect parts of northern, central and southern Europe... Strong low-level depression will develop along its upstream side and should continue to move towards the NNE.
Weak ridging will affect Spain with hot and dry conditions.

DISCUSSION

... Eastern and northeastern Europe...

Conditions will become favorable for an outbreak of severe TSTMs over a broad area over north-western Russia!

Well developed upper-level trough will shift towards a more negatively tilted position, as an intense speed max in the upper levels will round the base, crossing Greece and the Black Sea region during the early morning hours....
Latest model runs consistently calculated pretty strong pressure falls in the area of interest as a result of an impressive coupled jet structure and a tightening baroclinic zone, stretching from the north towards the south over western Russia.
Model pool agrees well on final strength of the depression (~1000hPa ) and also calculates a more or less closed circulation.
This depression will only support northward transport of a warm and very humid airmass ( yesterday readings already showed dewpoints of 17-20°C in the northward moving warm sector) and this, combined with rapidly steepening lapse rates //mainly northeast of Moscow// should release up to 2000 J/kg instability.
Scattered TSTM development expected over Belarus and eastward (mainly along the <> ) due to a weakly capped atmosphere.... Enhanced LL shear and DLS in the order of 20-25m/s ( east of Belarus) would favor storms to organize pretty fast with an attendant severe wind gust and large hail threat....TSTM activity should diminish from the south, due to the advection of a drier and cooler airmass.

The main concern arises during the later afternoon hours over a region around,north and northeast of Moscow ( continuing out of our area of responsibility towards the east )...
Intense pressue fall due to the approach of the low-level depression, combined with high instability values and more than adequate kinematic parameters will create a favorable environment for severe TSTMs.
Current thinking is, that storm coverage in the level-2 area should increase during the early afternoon hours from the south.
Very low LCLs and a possible well developed backing wind field in the NE-quadrant of the low-level depression will create a fine environment for tornadoes, some of them even strong !... Steepening lapse rates and DLS up to 30m/s will also favor large or even very large hail, mainly in discrete developing storms...
By degrees,the approach of the depression and a strengthening speed max from the south constantly impressive upper- level divergence values should help to organize a line of storms, racing N/NE-ward, with an attendant severe wind gust threat.

The area will be monitored, if higher probabilities may become necessary later on!

....Central Mediterranean and parts of central Europe...

Cool mid-level airmass will continue to affect the central Mediterranean, but current thinking is, that main TSTM activity will continue to be mainly offshore due to higher ” T's (SST-500hPa).
Weak instability and shear should preclude a more organized severe TSTM threat.

Influx of cold mid-level air over NE-Germany and steepening lapse rates should (re-)activate shower activity and don't want to exclude a few electrified storms... Again... expect mostly sub-severe wind gusts with maturing showers/storms.