Storm Forecast
Valid: Fri 02 Dec 2016 06:00 to Sat 03 Dec 2016 06:00 UTC
Issued: Thu 01 Dec 2016 17:23
Forecaster: TUSCHY

A level 1 was issued for E-Slovakia, E-Hungary, the W-Ukraine and parts of Romania mainly for severe wind gusts and an isolated tornado event.

SYNOPSIS and DISCUSSION

A stable configuration of a ridge to the west and a deep trough to the east support ongoing influx of cold/cool air mass over most parts of Europe with some BL air mass modification over offshore regions. There, a few areas with lightning probabilities exist, but nothing severe is anticipated.

The only area of interest is an ongoing cold frontal passage during the 06-12Z time frame, which exits E-Slovakia/far W-Ukraine and affects E-Hungary and parts of Romania. Good placement beneath the left exit of a powerful mid-level jet and meager prefrontal BL moisture advection combined with strong lift result in somewhat deeper convection along the cold front.

Severe wind gusts will be the main risk, although an isolated tornado event can't be ruled out. Generally meager BL moisture should limit the overall tornado risk, but locally enhanced BL moisture and orographically induced enhanced directional shear (in addition to already high SRH-1 values) are enough arguments for adding a low tornado risk. We thought about adding a small level 2 for widespread severe wind gusts, but again, meager BL moisture and very low CAPE lowered confidence in adequate thunderstorm coverage. Also, no confined and intense LLJ speed max is expected but more a broader and weaker LLJ structure, which also lowers the probabilities for extreme gusts. The area needs to be monitored closely in case of more robust CAPE release due to better dry slot/BL moisture overalp than currently anticipated.
The hazard diminishes east/southeast and beyond 12Z as CAPE decays.