Storm Forecast
Valid: Tue 10 Apr 2018 06:00 to Wed 11 Apr 2018 06:00 UTC
Issued: Mon 09 Apr 2018 21:46
Forecaster: DAFIS

A level 1 was issued for S France mainly for excessive precipitation, severe wind gusts and tornadoes/waterspouts.

A level 1 was issued for N Algeria and Tunisia mainly for large hail and severe wind gusts.

A level 1 was issued for SE Turkey, Syria and NW Iraq mainly for large hail and severe wind gusts.

SYNOPSIS

A complex pattern of many short-wave troughs is currently developing over Europe. The most pronounced disturbance will be a cold drop approaching the Iberian Peninsula from NW during Tuesday 10/04, further destabilizing the already unstable air masses over the area. Another trough crosses W Mediterranean, along with a cold front at the surface with a strong LL SW flow which advects moist air masses from the sea onshore France and NW Italy. The same trough will be responsible for organized convection in N Africa. A cut-off low is stalled in far East Mediterranean, resulting in very steep lapse rates and widespread thunderstorm activity. Finally, in C and E Europe, we expect pulsating thunderstorms within convergence zones on stationary fronts, feeding on warm and moist LL air masses and diurnal heating.

DISCUSSION

As mentioned above, widespread thunderstorm activity is expected. DLS does not overlap with high CAPE in most cases, but areas with high CAPESHEAR values are highlighted with level 1 areas.

In S France the ongoing thunderstorm activity is expected to become more organized by the passaged of a jet streak over the Gulf of Lions in the morning of Tuesday. Persisting storms on the Massif Central and SW Alpes may result in excessive precipitation and locally severe wind gusts. Due to strong LL flow and high LLS, tornadic events near the coasts cannot be ruled out, especially in the event of a waterspout formation that can later get onshore. Waterspouts are also expected behind the cold front when weak wind fields and cold mid-levels will prevail.

Another jet-streak is forecast to cross N Africa, organizing storms inside an environment with steep lapse rates and dry LLs. Large hail and severe wind gusts are expected in the afternoon.

In Turkey, Syria, and Iraq, the cold bubble will provide favorable conditions for the development of many storm cells, some of them will be able to cluster, mostly in Turkey, since DLS is forecast to exceed 25 m/s. Large hail and severe wind gusts are expected.