Storm Forecast
Valid: Tue 24 Jan 2017 06:00 to Wed 25 Jan 2017 06:00 UTC
Issued: Mon 23 Jan 2017 23:00
Forecaster: DAFIS

A level 1 was issued for s S Greece and SW Turkey mainly for excessive rainfall, large amounts of small hail, severe wind gusts and tornadoes.

SYNOPSIS

Several progressive short-wave troughs and low geopotentials prevail over the European domain. During Tuesday a ridge is forming in West Europe and the mid-level cold pool over the Mediterranean Sea travels east. Near the surface, a high pressure system will cover most of Central Europe whilst Italy and Greece will be under low pressure systems, which produce several waves, destabilizing the area marked with 15-50% of lightning probability.


DISCUSSION

During the morning of Tuesday a cold front will approach the SW coasts of Greece, moving progressively NE during the day.
Modest prefrontal moisture with adequate forcing (in terms of PVA) could support a broken line of enhanced convection. Also, as deeper updrafts can reach 500-400 hPa, they should be able to take profit of the strong mid-layer shear. DLS up to 35 m/s with SRH0-3 km exceeding 300 m²/s² could form bowing line segments, which enhance the downward transport of 20-25 m/s winds from 850 hPa over the Aegean between 09-18z. The main threat for strong downward mixing of strongest winds will be along the cold front, which is just about to enter the forecast area around 09z. Therefore, a level 1 was issued for isolated convection embedded in enhanced low level flow. Storms will be capable of producing heavy rainfall, especially near the coasts of Turkey, where tail-end storms can form and large amounts of small hail as MLCAPE is calculated up to 500 J/kg, DLS 25-35 m/s and wet bulb temperature freezing level is just above 1000m.
Finally, a few waterspouts cannot be ruled out along the coasts, where LL instability is present and LLS reaches 10 m/s.