Storm Forecast
Valid: Sun 25 Sep 2011 06:00 to Mon 26 Sep 2011 06:00 UTC
Issued: Sat 24 Sep 2011 19:06
Forecaster: SCHLENCZEK

A level 1 was issued for E Algeria, Tunisia and parts of the S-central Mediterranean mainly for large hail and severe wind gusts.

SYNOPSIS

Warm and mostly stable conditions prevail over central and eastern Europe also on Sunday. The highest instability can be expected over the southern Mediterranean region in an environment with 10 - 15°C at 850 hPa.

DISCUSSION

...S-central Mediterranean, Tunisia, E Algeria...

Locally high instability with MLCAPE in order of 1500 J/kg is forecast for the southern Mediterranean and parts of Algeria / Tunisia. High CIN is in place which should suppress convective activity in most places. A weak upper trough could provide some QG forcing when approaching S Italy / Sicily during the afternoon but this scenario is quite uncertain. As convective precipitation is forecast by GFS and WRF-NMM, the development of storms is more likely than not and a level 1 is introduced for the region with the highest probability of convective initiation. Due to strong vertical shear (15 - 20 m/s from 0-6 km AGL), storms will likely become multicellular or supercellular. The main threat is large hail and / or severe wind gusts.
Please note that the level 1 region also covers the places further inland which are not shown on the map.