Storm Forecast
Valid: Wed 21 Oct 2015 06:00 to Thu 22 Oct 2015 06:00 UTC
Issued: Wed 21 Oct 2015 06:21
Forecaster: PUCIK

A level 1 was issued for Sicily, Ionian Sea, W Greece mainly for excessive precipitation and to the lesser degree large hail and severe wind gusts.

SYNOPSIS

With an extensive ridge over the Atlantic, northerly flow at its edge covers a large part of W Europe. Embedded in this flow, a cyclonic vortex moves from NE Spain towards N Africa during the day. Another cyclonic vortex will reside over E Poland / Belarus / W Ukraine. Scattered DMC activity is forecast over the parts of S, Central and E Mediterranean, where abundant low-level moisture is observed and coastal stations report dewpoints of 16 - 20 deg C. In westerly to southwesterly flow, steep lapse ratse are advected from N Africa towards the Ionian Sea, where the highest CAPE values are forecast.

DISCUSSION

... Sicily towards W Greece ...

A scattered DMC activity is already observed along the left exit region of the strong subtropical jet-stream. Satellite loops show two embedded troughs within the jet-stream approaching Sicily. Underneath the jet, strong vertical wind shear is present with DLS values above 20 m/s, already favourable for well organised modes of DMC. Primary threat should be excessive precipitation due to the moist conditions, low LCLs and high PWAT values. Especially with supercells, large hail and severe wind gusts may occur as well. These threats will be confined more to SE Sicily and W Greece (or generally Ionian Sea) thanks to the presence of steep lapse rates and higher CAPE values. Tornadoes can not be completely ruled out (particularly in the narrow belt of higher LLS just east of Sicily), but are less likely than the other threats. The highest risk of severe weather over Sicily will be present during the day time hours, while over W Greece it will be most pronounced during the night and Thursday morning.