Storm Forecast
Valid: Tue 08 Nov 2016 06:00 to Wed 09 Nov 2016 06:00 UTC
Issued: Mon 07 Nov 2016 23:06
Forecaster: DAFIS
A level 2 was issued for West Greece and Albania mainly for excessive rainfall, large hail, severe wind gusts and tornadoes.
A level 1 was issued for S Italy, Malta, Bosnia and Herzegovina, Montenegro, Albania, W FYROM and Greece mainly for excessive rainfall, large hail, severe wind gusts and tornadoes.
A level 1 was issued for W Mediterranean basin mainly for severe wind gusts and tornadoes.
SYNOPSIS
Very cold air masses prevail over West and Central Europe, while a long-wave trough crosses the continent from west to east, bringing moist air masses over the Balkans. Another short-wave trough will cross Ireland and UK during the afternoon, entering France during the night of Tuesday. At the surface, the main feature will be a cold front crossing Ionian Sea, moving towards Greece and Albania, leading to severe DMC events.
DISCUSSION
.... S Italy, Malta, Bosnia and Herzegovina, Montenegro, Albania, W FYROM and Greece ....
As the LL vortex over Italy and the Adriatic Sea will remain stationary for a couple of hours during Tuesday, the leading edge of a cold front approaching the Balkans from the SW will result in an outbreak of organized thunderstorm activity, where strong BL convergence will take place. The unobstructed inflow of moist LL air masses with mixing ratios up to 13 g/kg in E Ionian Sea in combination with steep mid-level lapse rates that will result in almost 1500 J/kg of MLCAPE. In addition to abundant synoptic lift as the vigorous long-wave trough is approaching, the vertical wind speed configuration, the overlap of 20-30 m/s DLS (or even more locally), 400-600 mē/sē SREH0-3km and the high CAPE values suggest a dangerous set up which favors strong, very well organized DMC, including long-lived supercells and large MCS all over the level 2 area. PW values reach the 35 mm, so excessive rainfall with major flood risk is issued for Montenegro, W Albania and W Greece. Very large hail and severe downbursts are likely beside an excessive rainfall risk. Due to the high LLCAPE, very low LCL values, the forecast of 300-400 mē/sē of SREH0-1km and the LLS exceeding the 15 m/s, we expect tornado events and/or a waterspout outbreak in Sicily, West Greece and Albania but also a significant tornado event in Albania and Greece cannot be excluded.
.... W Mediterranean basin ....
Cold mid-level air masses result in steep lapse rates and some hundreds of CAPE among several convergence zones. Some storms will be able to produce severe wind gusts as dry low level air masses will create a favorable environment for downbursts. Slow storm motion vectors also suggest that these storms may be stationary, able to produce waterspouts or landspouts.
