Storm Forecast
Valid: Sun 15 Feb 2015 06:00 to Mon 16 Feb 2015 06:00 UTC
Issued: Sun 15 Feb 2015 03:13
Forecaster: TASZAREK

No threat levels were issued

SYNOPSIS

Blocking pattern continues over Europe. Thanks to high pressure with center over Scandinavia (1040 hPa), central, N, and E Europe will stay under influence of stable polar and arctic dry air masses of continental origin. Moister and warmer air will be located in the SW and S Europe within the belt encircling high over Scandinavia. Cut-off lows over France and Turkey divided by ridge over Balkan Peninsula will provide conditions for thunderstorm development, mostly in low-sheared environment. Minor and shallow jet streak will be located in the W France.

DISCUSSION

Thunderstorms are expected to occur in polar air masses of marine origin over W and C Mediterranean. Within mixing ratios up to 7 g/kg, highest CAPE values are forecast to occur over sea surface and reach peak near Sardinia up to 800 J/kg. Lightning are the most likely in the northern flank of the low-leveled cut-off over France, that in the forecast period is expected to move towards Sardinia, and deepen to 1005 hPa. Thunderstorms that will occur in SW France from 12-18Z will be supported by DLS up to 30 m/s, however due to marginal flow in low and mid levels, and rather marginal instability, level 1 is not issued. Although probability for severe weather is small, given steep lapse rates and mixing ratios up to 6 g/kg, large hail phenomena cannot be ruled out. The rest of the lightning areas will remain in low-sheared and low CAPE environment that is not conducive for severe weather phenomena associated with convection. Thunderstorm activity over the sea will be evenly distributed during the forecast period, while over the land it should peak in the afternoon hours.

High sum of precipitation exceeding 100mm in the forecast period (mostly of non-convective origin) are forecast over Liguria and Aosta Valley in NW Italy.