20-05-2012 06:39 | Estofex | m.b.t. 20-05-2012 t/m 21-05-2012
Storm Forecast
Valid: Sun 20 May 2012 06:00 to Mon 21 May 2012 06:00 UTC
Issued: Sun 20 May 2012 06:39
Forecaster: GATZEN
A level 1 was issued for western and southern Germany, the Benelux countries, and eastern Spain mainly for large hail.
A level 1 was issued for southern France and north-eastern Spain mainy for excessive precipitation.
A level 1 was issued for western Russia, the southern Baltic States, Belarus, eastern Poland, western Ukraine, Romania, Moldova, Bulgaria, Slovakia, and eastern Hungary mainly for large hail.
SYNOPSIS
A polar trough amplifies across western Europe and will form a cut-off low centered across northern Iberia at the end of the forecast period. The low geopotential yields a southerly to south-westerly mid-level flow from the west Mediterranean to southern Scandinavia and warm air advection is expected over most of central Europe. Farther east, a cut-off low located over western Turkey will remain quasi-stationary. Warm and unstable air is advected westward across the Black Sea region today.
DISCUSSION
Eastern France, southern Germany
The southerly flow will lead to intense warming to the north of the Alps today. Steepening lapse rates are expected to spread across southern Germany and eastern France. At low-levels, diurnal heating will result in easterly or north-easterly winds that will be associated with upslope flow. The low-level missing ratio will increase to about 9 g/kg in the lowest km. Together with the daytime heating MLCAPE in the order of 800 J/kg is forecast.
Current thinking is that storms will start over eastern France and will spread into south-western and central Germany in the afternoon hours. With moderate vertical wind shear, well-organized multicells and a few supercells are not ruled out. The main threat will be large hail with these storms. In the evening hours, isolated storms may also develop further east along the northern Alps. These storms will also have a potential to produce large hail. In the evening and night hours, storms are expected to weaken.
(Alleen de voor NL een aangrenzende gebieden relevante tekstdelen overgenomen, klik hier voor de volledige forecast, red.)
Verwachtingen/waarschuwingen
