Storm Forecast
Valid: Sat 11 Feb 2017 06:00 to Sun 12 Feb 2017 06:00 UTC
Issued: Sat 11 Feb 2017 00:46
Forecaster: TASZAREK

A level 1 was issued for E Spanish coast mainly for the large hail.

A level 1 was issued for S Portugal and parts of SW Spain mainly for excessive precipitation.

SYNOPSIS and DISCUSSION

Broad high with cold airmass prevails over N Europe. Mid-level cold core is placed over Benelux while a well developed low covers waters SW of Portugal. A weakly pronounced shortwave travels trough E Mediterranean. Thunderstorms are possible in SW part of Iberian Peninsula where 6-7 g/kg mixing ratios overlap with pockets of enhanced lapse rates (> 7 K/km), and persistent synoptic-scale lift. Rather small CAPE (~200-400 J/kg) and weak vertical wind shear limits the potential for severe convective phenomena. However, given 24-hour period, a quasi-stationary convection over S Portugal and SW Spain, and superimposing large-scale precipitation pose a threat for excessive precipitation and a possible local flash flooding.

On the far eastern flank of the low (E Spanish coast), a low-level inflow of moist air from Mediterranean area overlapping with steep lapse rates from Sahara (> 7.5 K/km) may produce few thunderstorms along coastal convergence zone. A local CAPE up to 600-800 J/kg in the zone of ~ 20 m/s DLS and 200 m2/s2 SRH may evolve some thunderstorms into low-topped supercells capable of producing severe weather including 2-3cm hail.

Some lightning activity in the morning hours is also possible between Crete and Turkey within a fading weak convection associated with a receding and weakening wave. Small CAPE and shear significantly limits severe weather potential.