Crazy supercells in NE-Slovenia on June 23rd

Favourable conditions in NE-Slovenia brought us some spectacular supercells. Some monsters were also in Austria and Hungary. I have never seen a more structured supercell in Europe. LP supercells at its finest.

Links to photos: http://forum.zevs.si/index.php/topic,3741.0.html

http://forum.zevs.si/index.php/topic,3735.0.html

http://forum.zevs.si/index.php/topic,3733.15.html

http://www.szupercella.hu/node/944

Here are some webcam screens from ARSO:

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!

And now for something completely different ... Lunar eclipse June 15th 2011

Another bust for N-Italy today so instead of storm images, I'm offering you something completely different! Here are some images from the June 15th lunar eclipse that was spectacular! You might have already seen the images on the Facebook account. Probably the darkest lunar eclipse I have ever seen. Dusk light gave a spectacular background setting.

Serious potential for strong (tornadic) supercells on June 18th in FVG, Italy

Estofex gave LVL2 for today in N-Italy and the setup really is very good. I won't really into details because time is not on my side. Just a quick writeup. 50 kt 0-6 km shear combined with good SFC winds with nice veering and moderate CAPE values suggests serious potential. The best potential is again in the FVG region where winds are the best. The cap is not small and there is no serious 10m convergence until 18Z so we will see if it can break it anyway. PWAT values are ridiculousy high, in the 42mm range, so everything points to (potentially tornadic) HP supercells. Good luck to everyone who will chase today. I won't be chasing because of college work. :(

June 6th - Classic supercell south of Krško/Brežice

I saw a lot of potential for E-Slovenia today (see previous posts), but the morning GFS and WRF models put me in a bad mood because they were seriously downgrading deep layer shear to the point where I saw no potential anymore. Later on, it got a tad better. A potential storm formed south of Novo mesto, and I jumped on it because I knew it could get strong given the moderate CAPE and better shear values further north. I was north of the cell the whole time. I tried to get east of the cell to get a better look, but the cell was moving sharply right and the Gorjanci mountain range (about 1000m high) limited my movement. I would waste an hour to get on the other side. I was hoping the cell would get into the Krško-Brežice valley where the conditions could be very good. That did not happen, it tracked right over Gorjanci and tracked eastward and slightly to the north. I only got one good look at it because of bad road connetions and hills on the south side. And it was a pretty one. It didn't look good at first, only the inflow banding was giving me some hope. At some point I was already contemplating about returning home, but the view got better so I waited a while and got rewarded with a nice classic supercell with a "barber pole" updraft. The supercell never looked very good on the radar, but it had nice structure nevertheless. On the radar image below you can see a significantly stronger cell some ten kilometers to the north, but the terrain there is awful, not chasable at all. So the supercell south of Krško and Brežice was probably the storm of the day.

 I was desperate to get east of it, so I went as far as the Croatian border, but at that point the storm had already dissipated once I got a better look at it. No other significant storms were in the area later that day.

Here it already had a nice inflow, but I was way too far north
to see anything else. Here I'm racing eastward.

Very nice wall cloud. Later on, the rain hide the
structure so had to race eastward again, with no luck.

Follow up on the June 6th setup

For initial analysis view the previous post. Potential for the June 7th has vanished due to weak 0-6km shear. June 6th looks solid, the 500mb jet is going to be stronger than expected at first.

We are dealing with 35-45 kt 500mb jet through northern Croatia, Slovenia and NE-Italy, around 30kt @ 700mb, 20kt @ 850mb and around 10kt @ 925mb and 10m. Limiting factor is the unidirectional shear, which limits helicity, so supercells are possible, but not very likely. Storms will tend to get linear. Focus will be on the southern flanks of the lines for possible tail-end charlies. CAPE will range from 500 to 2000 J/kg according to WRF and GFS, locally maybe even more. Areas with high CAPE are forecast in CNTR-Italy, E-Slovenia and N-Croatia. No significant convergence lines other than above the Dinaric mountain range and the Alps are forecast, but the CINH will be rather small and with some daytime heating we should have no problem seeing breaking the cap. Similar conditions exist for E-Austria and W-Hungary.

Severe weather potential for N-Italy, June 6th/7th

Weak trough passes through central Europe, showing some signs of storm potential. As I look at it now, the limiting factor will be the upper level flow, only at 30kts @ 500mb which is seriously borderline. Low level winds on the other hands are quite good, with good speeds and direction make up for a nice veering profile. Higher CAPE is forecast on June 7th with more marginal conditions on June 6th. The cap will be somewhat moderate, but with lack of surface convergence, initiation is questionable. WRF is even drawing a 10m wind divergence in FVG region. Stay tuned for updates and detailed analysis in the next few days.