Storm Forecast
Valid: Mon 22 Jan 2018 06:00 to Tue 23 Jan 2018 06:00 UTC
Issued: Mon 22 Jan 2018 02:51
Forecaster: VAN DER VELDE

A level 1 was issued for southern Turkey mainly for chances of excessive convective rainfall, tornadoes and large hail.

A level 1 was issued for eastern France and Switzerland mainly for chances of severe convective wind gusts.

SYNOPSIS

A northwesterly flow in mid/uppper levels is in place between Scotland and a large trough over Turkey. In this flow a sharp shortwave trough and cold front passes over France, Switzerland and Italy with some potential for convection. The main system is the Turkish/Black Sea low slowly moving eastward, with a cold front advancing along the south coast of Turkey.

DISCUSSION

...S Turkey, Cyprus, W Syria...

Persisting convergence parallel to the coast and lifting of moist air over the higher terrain in coastal areas in the warm sector in 200-500 J/kg MLCAPE will likely trigger storms that leave a few tens of millimeters rain in many locations, in some places more. Storm-relative helicity over 250 m2/s2 supports mesocyclonic updrafts with chances of tornadoes and large hail. In the colder air mass waterspout-type tornadoes can appear.

...E France, Switzerland...

Very slight CAPE signals, mostly elevated parcels, are associated with this marked PV feature overpass. Strong lifting and a clear surface front are present in model output. In case this manages to materialize to convection, a linear system could be the mode, and may produce severe wind gusts.