![]() ![]() ![]() Similar CAPE and shear conditions are in place on the French side of the Pyrenees, which will likely be reached by the storms by sunset. ![]() The possibility of both a high coverage of severe weather and of a handful of extreme hail and/or wind events justifies a level 2. The main hazard is large hail with discrete storms (in particular supercells), before it turns to severe wind gusts and heavy rain in case convection grows upscale. A quick organization into strong multicells, supercells and later perhaps a larger linear system, driven by strong downbursts in the hot airmass, is expected. By early afternoon, a pronounced sea breeze front / dryline will likely establish downstream (NE) of the Iberian System mountains, and scattered convective initiation becomes more and more likely over those mountains that can still be reached by the moisture tongue from the Ebro valley. One or two clusters of elevated and probably non-severe storms may already be active in the morning, but should decay and/or move away towards the NE soon enough to allow plentiful sunshine and strong daytime heating. Courtesy to the subtropic jetstream aloft, deep-layer shear rises from 20 m/s in the Basque region to 30 m/s near the Spanish east coast, providing excellent conditions for storm organization. Convective initiation is hampered and delayed by a capping inversion beneath the EML, but synoptic lift (both from warm air advection and from subtle short-wave troughs) appears strong enough to allow upvalley/upslope circulations to break this cap. High CAPE, probably on the order of 1000-2000 J/kg, builds in the sea breeze and upvalley flow regime of the Spanish east coast and the Ebro Valley, which feeds plenty of low-level moisture with 2m dewpoints in the upper tens beneath an elevated mixed layer (EML) that detaches from the high and dry inland areas. Last but not least, an extensive but weak mid-level low is present over SE Europe with seasonable temperatures and unsettled weather. Near the surface, the accompanying diffuse frontal zone acts as a cold front from the Baltic States to the Alpine region and turns into a warm front towards France and Spain. At 500 hPa, the flow is split up into a polar jet from the British Isles towards Finland and a subtropic jet over Iberia and the Mediterranean Sea. All in all, this configuration results in a broad, meandering westerly to southwesterly flow over most of the continent. Two other cyclones are present west of the British Isles and Iberia. A cyclone (responsible for an extraordinary summertime windstorm in the Netherlands and NW Germany on Wednesday) fills up over S Sweden. A level 1 and level 2 are issued for NE Spain and S France for large hail, severe convective wind gusts and excessive convective precipitation.Ī level 2 and level 2 are issued for N Italy for large hail, excessive convective precipitation and to a lesser degree for severe convective wind gusts.Ī level 1 and level 2 are issued for SE and E Europe, as well as for W Turkey, mainly for excessive convective precipitation and large hail.Ī complex weather pattern is in place in the European sector.
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