LVL2 setup in N-Italy, N-Balkans

Estofex gave LVL2 for todays setup and I mostly agree with the forecast. Cold front moves through central Europe in late thursday/friday. Moisture pooling allows for high CAPE, while deep-layer shear seems to be in the 20 m/s range while CAPE is very local, up to 2500 J/kg. There is no severe veering wind profile, so the SREH3 seems to be limited, but the best areas seems to be in the FVG, CTRL-Slovenia and SE-Slovenia/N-Croatia where the wind is best. So supercells are very much possible and given the low PWAT values we could see some nice classic ones. Main dangers will be large hail and strong winds. I can't give an exact target area because the area of possible activity will be rather large, and initiation is possible anywhere. There is a rather strong convergence along the Dinaric mountain range, but it will be mostly capped, except for the NW part. All-in-all, a pretty favourable setup for storm-chasing but a very dangerous situation for general public, we could see some major damage.

Happy hunting!

Severe storms potential on Friday in FVG, Italy

Severe weather is expected on Friday afternoon in Italy, Austria, Slovenia and Hungary as the trough advances eastward. The trough will provide a 15-20 m/s 500mb jet and adequate lift on the front which comes in the late afternoon in N-Italy, N-Slovenia and W-Hungary. Models still do not agree with each other on how much CAPE will be available although they are starting to converge. GFS forecasts >1000 J/kg in NE-Slovenia, >1500 J/kg in N-Croatia and only a couple of hundred in central Italy with marginal CAPE in Friuli-Venezia region. ECMWF and GFS are drawing more CAPE in FVG region and less in NE-Slovenia.
The wind profile is great in the FVG region and a lot worse elsewhere. Medium SRH3 and nice veering suggest for potentially tornadic supercells. That will be basically the only interesting region. Other locations have more or less uni-directional shear so linear storms will probably be the primary mode. Still, large hail is definitely a danger, including severe wind gusts, but to a lesser extent, given the high moisture and PWAT values. High PWAT values also suggest HP supercells in the FVG region. With some low-level shear, tornado is not ruled out.

My biggest concern is the capped atmosphere in the FVG region. Elsewhere the cap will be broken rather easily. I remain somewhat sceptical for Italy. There is a strong convergence west of Venezia and Bologna, but the lack of serious lift in FVG region, the initiation prior to the front is questionable. Once the front comes, there will be no problem with initiation, but this will probably be rather late. I think the CIN will be in the 30-60J range and with the lack of serious convergence zones the initiation can be late.

The severe weather potential in NE-Slovenia and elsewhere along the front will be limited due to lack of low-level shear and these locations are probably not the best chasing targets.

May 3rd 2011 - Storm with shelf cloud in SE-Slovenia

Another weak front passed us today. Only marginal CAPE with weak deep layer shear was present, but the front provided enough lift for some semi-serious storms to form. I got a nice view of a shallow shelf cloud in the vicinity of my home. It was really a multi-cellular mess. Only this storm showed some signs of organization, everything else was just not worth looking at. Some nearby cells really killed the action on the cell I photographed. It was soon digesting downdrafts from other cells and died soon after that.

Yeah, we've seen better but given that the season sucks so far and it's still early May, I'll take this one.

Wall cloud of the first cell of the day that did not produce anything.

Distant wall cloud.

Forming shelf cloud approaching.

Funky looking tornado-like structure. Nothing serious.

Probably the best look of the storm I got.

Wall cloud with the shelf above.

Weak supercells possible tommorow across Serbia

Some marginal CAPE buildup on March 17th (up to 500 J/kg MUCAPE is forecast) in front of the cold front with the surface low somewhere above N-Austria. Potential for rotating storms exists in the central and eastern Serbia where SREH3 gets up to about 200 m2/s2. DLS is about 20 m/s. Main threat will be hail. CIN will be low so the storms will fire up fairly quickly. I usually wouldn't care for this type of setup, but in the early spring (late winter) every semi-severe convective weather is a welcome change.

August 13th 2010 - Cold front passing in Medvedje Brdo, W-Slovenia

The front arrived in the morning. Wasn't expecting much, but got surprised! A morning shelf cloud and what a spectacular one!

May 3rd 2009 - Shelf cloud

Surprising shelf cloud from a really crappy storm. Conditions weren't good at all, so I was at home all the time, but this was quite surprising! Solid winds on the ground but nothing spectacular.