Storm Forecast
Valid: Thu 14 Apr 2016 06:00 to Fri 15 Apr 2016 06:00 UTC
Issued: Wed 13 Apr 2016 23:02
Forecaster: GATZEN
A level 1 was issued for Bosnia-Herzegovina, Serbia, Bulgaria, Romania, Moldova, and south-western Ukraine mainly for large hail and to a lesser extent severe wind gusts and tornadoes.
SYNOPSIS
A zonal flow affects southern Europe at the edge of low geopotential that extents from west to east. With the strong westerly flow, intense vort-maxima travel east and will especially affect western Russia, south-eastern Europe, and parts of western Europe. Ahead of the south-east European vort-max, a tongue of subtropical air and associated elevated mixed layer spreads into the Black Sea region. It overlaps with some better low-level moisture, and CAPE can develop. Further west, maritime air masses characterized by weaker lapse rates will be present.
DISCUSSION
Bosnia-Herzegovina and Serbia into Bulgaria, Romania, and south-western Ukraine
Ahead of an intense short-wave trough that moves east, DCVA is forecast on Thursday. At lower levels, the tongue of warm air will be pushed into the Black Sea early in the period. In the wake of the warm air axis, some cold air advection is indicated by latest models. However, thermodynamic environment will remain relatively moist. With some diurnal heating, CAPE can be expected to reach a few 100 J/kg.
Main forcing will be close to the left exit region of an intense jet streak that curves around the short-wave troughs base. It will affect Bosnia-Herzegovina and Serbia in the morning hours, where first storms are forecast, spreading east during the day. Storm intensity will increase as CAPE increases with stronger low-level heating. Additionally, strong vertical wind shear exceeding 15 m/s in the lowest 3 km will allow for organized storms.
Main threat will be large hail, especially when supercells form. Additionally, severe wind gusts and tornadoes are not ruled out given strong low-level vertical wind shear. Storms will move into the Black Sea later on where they weaken.
