Outlook day 1 (valid: 18/09/2014)

VALID FOR 18-09-2014

*** A significant flooding event is likely to occur in parts of southern France on Thursday. Locally, very high amounts of rainfall (150-200mm or more in 24 hours) are again expected. ***

A powerful upper low centered NW of Iberia is gradually weakening on Thursday while at extensive ridge remains over NE Europe. Strong SSW-erlies are continue advecting humid and strongly unstable airmass into SW Europe. The upper low over N Turkey finally weakens while progressing east.

A HIGH risk has been issued for southern France with threat for torrential excessive rainfall which could result in severe flooding. A moderately unstable airmass with up to 1500 J/kg MLCAPE persists over the northern Mediterranean. Moderately strong shear will again support multicell clusters with training effect and strong orographic effect, that will produce very high rainfall cumulatives. Over 200 mm / 24h is locally possible. Aditionally, strong LL shear enhances tornado threat in the coastal area.

A MDT risk has been issued for surrounding areas of HIGH risk including S France and extreme NW Italy threat for excessive rainfall and additional tornado threat.

A SLGT risk has been issued for the Iberian Peninsula, France, W Germany and NW Italy for excessive rainfall.

A MDT risk has been issued for extreme NW Turkey for excessive rainfall.

A SLGT risk has been issued for the area surrounding MDT risk in Turkey for excessive rainfall and marginally large hail.