Storm Forecast
Valid: Mon 23 Mar 2015 06:00 to Tue 24 Mar 2015 06:00 UTC
Issued: Mon 23 Mar 2015 06:16
Forecaster: VAN DER VELDE
A level 1 was issued for southeastern Spain mainly for isolated large hail.
A level 1 was issued for northern Algeria mainly for isolated large hail.
A level 1 was issued for Albania and western Greece mainly for isolated hail/tornado chances.
SYNOPSIS
Low pressure systems are found over the Norwegian Sea and Scandinavia, another over the Iberian Peninsula extending to the western Mediterranean basin. Surface high pressure resides over the Atlantic and the Romania/Ukraine region. A mid level ridge keeps ensures stable condtions across central Europe. Relatively low 500 hPa temperatures from an old trough extend between Spain and Turkey, with slightly unstable conditions throughout this region. A shortwave trough with a low level warm sector is weakening in the early hours of Monday over the Ionean Sea. Low level warm air advection will pick up over the western Mediterranean with strong lapse rates moving out of Algeria.
DISCUSSION
...Ionean Sea shores...
New storms may form across the coastal region where modest CAPE remains with somewhat elevated shear conditions SREH is elevated over 100 mē/sē and 0-6 km shear of 20 m/s. An isolated cell may be organized enough to produce large hail or perhaps a tornado/waterspout.
...eastern Spain..
An upper trough creates lift over the eastern half of Spain. Some 10-15 m/s deep layer shear is combined with 200-500 J/kg MLCAPE which may enhance chances of marginally large hail. On the other hand, the low LCL height is not favorable. Excessive convective rain chances decrease as the flow becomes stronger.
...Algeria and southern Mediterranean...
Storms may struggle to initiate in very dry air and modest CAPE over northern Algeria despite lack of CIN. GFS model does produce many convective rain signals. The situation should improve as strong lifting from the upper trough reaches eastern Algeria around 00Z and the southern Mediterranean Sea where more moisture is becoming available. Still, the unstable parcels appear to remain elevated above a stable surface layer. Effective vertical wind shear is strong and supportive of supercells with chances of large hail.
