Storm Forecast
Valid: Mon 26 Dec 2016 06:00 to Tue 27 Dec 2016 06:00 UTC
Issued: Mon 26 Dec 2016 05:55
Forecaster: VAN DER VELDE

*** Wind speeds in excess of our extremely severe criterion will be possible over the northern North Sea, Skagerrak, Kattegat and southwestern Baltic Sea ***

A level 1 was issued for parts of Denmark, SW Norway and Baltic States mainly for chances of tornadoes.

SYNOPSIS

An aggressive depression (around 960 hPa) initially west of Norway, moving to the Baltic Sea, sets up very steep pressure gradients which suffice for widespread severe to extremely severe wind gusts. Very steep lapse rates guarantee thundery convection. However, chances of dynamically organized forms of deep convection appear to be low within the cold moisture-starved low CAPE airmass, such that we do not issue a level 3 for severe convective wind gusts. There are enhancements of low-level shear over land due to friction, to values >15 m/s supportive of tornadogenesis. In these regions a level 1 was issued for tornado chances.