Storm Forecast
Valid: Mon 08 Jun 2015 06:00 to Tue 09 Jun 2015 06:00 UTC
Issued: Mon 08 Jun 2015 00:02
Forecaster: DAFIS

A level 1 was issued for parts of Switzerland, Austria and N Italy mainly for excessive precipitation.

A level 1 was issued for central parts of Italy mainly for large amounts of small hail and excessive precipitation.

SYNOPSIS

A high pressure system is approaching the British Isles from the west and a trough with an SW axis is moving slowly south-eastwrads from the North Sea area. Also a cold pool of upper air is present in central Mediterranean where strong low level winds dissipate. Rather weak storms are expected in parts of S France and NE Spain, NE Europe, especially in Russia, in southern Balkans and in Turkey where small hail events is the main threat.

DISCUSSION

....Northeastern Alps....

Very moist boundary layer (mixing ratios 10-13g/kg) exists in the northern parts of Alpine region which overlaps with high values of MLCAPE (1800-2000J/kg) and regarding very weak DLS 0-6km, the storm cells that are expected to be quasi stationary. Models simulate a low level convergence zone in central Austria, where the strongest convection initiation is expected. Large hail is not predicted as supercells are not expected to form into this environment and also severe wind gusts will not be a threat in such a moist BPL.

....Central Italy....

Very steep lapse rates (> 10K/km) overlap with high values of MLCAPE (1500 - 2000J/kg simulated by GFS and high resolution models). DLS 0-6km is weak (<10m/s), so single cell storms are expected to stay stationary, producing large amounts of precipitation mostly at the mountainous areas of central Italy (BPL mixing ratio >10g/kg), where large amounts of hail is not ruled out.