Storm Forecast
Valid: Tue 22 Jan 2019 06:00 to Wed 23 Jan 2019 06:00 UTC
Issued: Mon 21 Jan 2019 23:30
Forecaster: DAFIS

A level 1 was issued for parts of Greece and Turkey for excessive convective precipitation, large hail, severe wind gusts, and tornadoes.

SYNOPSIS

Cold air masses have invaded Europe as a long-wave trough with a positive tilt is extending from NE Europe towards W Mediterranean. Another cold outbreak is expected on Tuesday 22/01, and this time a maritime polar air mass is moving fast from NW Atlantic towards Europe. Snow and freezing conditions will be the main threat along the continental parts of the continent, but later this week a dangerous set-up is building up in C-W Mediterranean, given a strong thermal gradient. At the surface, a rather shallow cyclone over Italy is moving slowly NE towards the Adriatic Sea, bringing unstable air masses to the Balkans and Turkey. A high-pressure system prevails in E Europe, while the cold front of a deep cyclone centered over Iceland, is currently affecting Ireland and the UK, progressively moving towards France tomorrow and stalling in North Sea.

DISCUSSION

.... Greece and Turkey ....

As the middle-level vortex over Italy tries to get aligned with the surface vortex, and before the dissipation of the whole system, the strong southwesterly flow in the Ionian and Aegean Seas will bring warm and moist, and thus unstable air masses onshore. Abundant QG lifting, mid-level lapse rates in the order of 7-8 K, PBL mixing ratios in the order of 8-10 g/kg and strong DLS create a favorable environment for all kinds of severe weather. First, the main threat in W Greece will be excessive precipitation and given the straight-line forecast hodographs we expect some linearly organized convection, better organized more to the south, able to produce severe wind gusts and hail near the coasts (DLS 15-20 m/s, MLCAPE 600-800 J/kg). In the afternoon convection will be most pronounced in NE Aegean where veering winds and a jet-streak at 850 hPa increase the threat of tornadogenesis. Excessive precipitation will be also a serious threat in NE Greece and W Turkey until midnight. After a few hours of limited severe weather, in the early morning of Wednesday, another cyclone will approach Greece, coming from SW, bringing more rainfall and hail.