Storm Forecast
Valid: Mon 13 Apr 2015 06:00 to Tue 14 Apr 2015 06:00 UTC
Issued: Mon 13 Apr 2015 01:40
Forecaster: VAN DER VELDE

A level 1 was issued for parts of Belarus and Ukraine mainly for severe convective wind gusts and a chance of tornadoes.

SYNOPSIS

A small upper low resides over the western Iberian Peninsula. To its north an anticyclone is in place over UK, France, Benelux and western Germany. Scandinavia and the Baltic states are under the influence of low pressure systems. A sharp cold front extends from the Baltic low south and westwards to the Alps. The active section moves from eastern Poland into Belarus and Ukraine with support of a deep PV feature which causes lift and destabilization.

DISCUSSION

...Belarus and Ukraine...

20-25 m/s mean wind speed between 1 and 3 km AGL can be transported to ground in thunderstorm downdrafts, which will most likely be concentrated in a linear convective system. The amount of CAPE (<250 J/kg) and low-level mixing ratios is modest while forcing and vertical shear are strong. At low levels 10-15 m/s 0-1 km shear supports both bow-echo and tornadic developments. Deeper shear vectors are perpendicular to the cold front, supportive of squall line traits. Marginal large hail may also be observed. The severe weather threats will likely be quite limited by the lack of buoyant energy.

...Hungary-Croatia-Bosnia area...

Higher resolution models are not really supportive of widespread convective activity, but shear is enhanced especially for elevated parcels. A marginal chance of large hail is present once a storm develops.