Valid: Wed 14 Mar 2018 06:00 to Thu 15 Mar 2018 06:00 UTC
Issued: Tue 13 Mar 2018 21:27
A level 1 was issued for Portugal and Southwestern Spain mainly for tornadoes and severe wind gusts.
SYNOPSIS and DISCUSSION
An active weather pattern continues for southern parts of Europe with a number of troughs crossing the region. Isolated to scattered DMC is forecast over Iberia, in conjuction with a deep low pressure system over the Atlantic and over southeastern Europe and Turkey, underneath a broad trough with axis stretching across the Balkans.
... SW Iberia ...
Ahead of a rapidly advancing short-wave trough, in the WAA regime, moist airmass, characterized by mixing ratios over 10 g/kg will have overspread much of the region by Wednesday morning. Moist airmass, along with a synoptic-scale ascent will contribute to the development of marginal latent instability. Forecast soundings show that much of CAPE will be confined to the temperatures around or above 0°C, so that some of the convective storms may not even be electrified. Nevertheless, particularly between 06 and 09 UTC, very strong lower tropospheric wind shear is forecast, with large and curved hodographs in forecast data. Considerable SREH and LLS around 15 m/s, together with low LCLs point to the significant tornado threat. Lvl 2 was considered for a combination of tornado and wind gust threat (as 850 hPa flow reaches 25 m/s), but was discarded due to the questionable degree of instability and also its nature (surface based vs elevated). Situation should be closely monitored though for any surface based supercell development in such setup!