Outlook day 1 (valid: 11/04/2018)

VALID FOR 11-04-2018

SYNOPSIS

A Rex blocking pattern dominates Europe on Wednesday, with an extensive upper ridge across N-NE Europe and a large upper low centered over SW Europe. Weak short-wave is pushed across N Balkan peninsula while a weak upper low remains over N Middle East region.

DISCUSSION

An ENH risk has been issued for W Alps with threat for excessive rainfall due to persisting SSE winds, resulting in strong orographic precipitation, locally resulting in more than 100mm in 24 hours period, flooding will be possible. Some convective precipitation cannot be rulled out either, resulting in training cells towards the mountainous terrain.

SLGT/MRGL risks have been issued for NW Italy into S France with threat for severe storms, capable of producing excesssive and torrential rainfall and severe winds. A good low-level wind shear / helicity could support rotating storms and enhance threat for tornadoes across SE France.

A MRGL risk has been issued for Sicily into Malta where some isolated threat for strong to severe storms exists, those could bring some severe winds and marginal hail events.

A MRGL risk has been issued for SE Turkey into Middle East where widespread slow moving showers and storms could support torrential rainfall and marginally large hail events.

A MRGL risk has been issued for W Ukraine into N Romania with threat for slow moving storms capable of producing torrential rainfall and marginally large hail events.

A WNTR risk has been issued for W Alps where excessive snowfall amounts are likely above 2000m ASL, locally 60-100cm are possible within 24 hours period.