Storm Forecast
Valid: Thu 26 Jan 2017 06:00 to Fri 27 Jan 2017 06:00 UTC
Issued: Wed 25 Jan 2017 22:45
Forecaster: GATZEN

SYNOPSIS / DISCUSSION

Amplified Atlantic trough approaches west of Europe on Thursday. Its leading occlusion runs into dry low-level air advected offshore from the British Isles and Iberian Peninsula. In its wake, intense jet streak is directed towards Morocco. Stretching of the maritime air mass allows for some CAPE over the Sea and also into Portugal late in the period with equilibrium level temperatures around -15°C. Showers and thunderstorms are forecast. Weak CAPE and limited low-level convergence are forecast, and organized deep moist convection is not likely.

Downstream of the digging west-European trough, ridging sets in across the central Mediterranean. Troughs that allowed for storms on Wednesday will move into drier air masses. One currently situated over the Balearic Islands will lift over France. It can still be associated with storms over the French coasts in the morning, although low-level moisture is decreasing along its path. Severe storms are not expected given weak CAPE and vertical wind shear. Over France, dry low-level air will quickly lessen thunder chances. A trough over the central Mediterranean is forecast to move into the Aegean region. Here, very dry low-level air mass will remain, and CAPE will disappear over most regions. Thunderstorms may be possible on Thursday morning over the Ionian Sea but will likely weaken until the afternoon as equilibrium levels become warmer in the wake of the leaving trough. With weak CAPE and shear, main threat of these storms are a few waterspouts at the start of the period.