Forecast Update
Valid: Mon 03 Sep 2007 06:00 to Tue 04 Sep 2007 06:00 UTC
Issued: Mon 03 Sep 2007 11:42
Forecaster: VAN DER VELDE

DISCUSSION

An update is warranted to account for the threat of waterspouts over western Finland and parts of the Baltic Sea. Especially in the area of Finland-Estonia-Gulf of Botnia, in the weak low pressure gradients, strong 0-3 km CAPE is present, well indicated by GFS00Z for the entire period and 00Z soundings of Jokioinen and Tallinn. 0-500m lapse rates are increasingly superadiabatic over water, helping rapid parcel ascent and vortex stretching.

Also the southern Baltic Sea area upgraded for the same reason. GFS model is more confident in low level instability at the end of the night as the system that is now still over the Norwegian coast passes over warm Baltic Sea surface.