Valid: Thu 28 Nov 2013 06:00 to Fri 29 Nov 2013 06:00 UTC
Issued: Wed 27 Nov 2013 21:19
SYNOPSIS / DISCUSSION
At mid-levels, a broad Mediterranean trough is present with a sharp axis from Iberia to the Adriatic. It will split up into two cut off troughs spreading eastward into the west Mediterranean Sea and the Atlantic. At lower levels, unseasonably cold and dry air masses have spread into the Mediterranean. Latest soundings indicate a deeply mixed and very dry boundary layer in the northern portions, whereas moisture is slightly increasing to the south, where at least weak CAPE is located in the boundary-layer. With northerly winds, advection of dry air goes on except for southern Italy and Sicily, where weak cyclogenesis is expected in the wake of the west-Mediterranean cut-off low.
Sea surface temperatures are about 13°C in the north and 16-21°C in the south Mediterranean. Low-topped showers and thunderstorms have developed near the troughs axis and further south on Wednesday. The focus of convective activity is expected to spread westward to the southern Balearic Sea and the Tyrrhenian Sea. But isolated storms will be also possible across the Adriatic and Ionian Sea. Weak vertical wind shear within the cloud layer will limit the potential of organization. However, steep lapse rates and weak flow can enhance the potential of waterspouts in the southern portions.
Across the east Mediterranean, low-level divergence is expected during the period. Only isolated storms may develop.