Storm Forecast
Valid: Tue 03 Oct 2006 06:00 to Wed 04 Oct 2006 06:00 UTC
Issued: Tue 03 Oct 2006 11:21

...Southeast side of Alps...

Tricky situation, where most of the level 1 area is actually expected to be capped under warm air advection into the low. Very strong shear conditions are in place under the jetstream, so anything that develops can become a very severe storm. Have chosen to highlight the northeastern Italy area by a level 2, where GFS model expects persistent convective precipitation mostly after 18Z, apparently due to upslope flow.

As the depression enters the area rather late, 12Z northern Italy soundings are likely to be not yet affected by deep lift/potential instability release and may not be much unstable. However, models do not show a concentrated vorticity maximum for this area, making the primary trigger the strong southwestern flow against the mountain range.

Very strong kinematic environment creates potential for severe to extreme convective weather events. DLS soars at >25 m/s, with 0-3 km SREH progged by GFS in the range of 300-450 m2/s2, more than adequate for supercells with large/very large hail, while very low LCL heights along with 12-18 m/s LLS indicate strong potential for (violent) tornadoes. Severe outflow winds can accompany any storm with 20 m/s already present at 850 hPa.


European Storm Forecast Experiment - ESTOFEX