Storm Forecast Valid: Mon 25 Aug 2014 06:00 to Tue 26 Aug 2014 06:00 UTC Issued: Sun 24 Aug 2014 22:01 Forecaster: PISTOTNIK
A level 1 was issued for some coastlines of Denmark, S Sweden and Poland for waterspouts.
SYNOPSIS and DISCUSSION
Two pronounced cyclones are placed over the British Isles and from Southern Scandinavia into the Baltic region. A strong zonal flow is present to their South, but temporary high pressure and dry, mostly cool air create often hostile conditions for deep convection.
Convection in the Northern half of Europe will mostly take place in well-mixed, weakly sheared polar air in the periphery of the two cyclones. Late in the forecast period, limited area models show well-marked convergence zones between Sweden and Denmark and along the Polish coast which could favor the development of a few waterspouts.
In the greater Mediterranean region, regionally rich moisture is still present but very weak lapse rates allow only limited patches of CAPE. Isolated to scattered showers are expected in the morning over the Adriatic Sea, the Northern Aegean Sea and the Bosporus (including the possibility of one or two waterspouts), and in the afternoon over orographic features of the Southern Balkans. However, forecast instability seems too shallow to produce a lot of lightning or to benefit from 15 to 20 m/s deep-layer shear.
An overlap of more robust CAPE and shear would be present over the Black Sea, but a strong cap will likely suppress convection.