Storm Forecast
Valid: Thu 20 Mar 2008 06:00 to Fri 21 Mar 2008 06:00 UTC
Issued: Wed 19 Mar 2008 21:42
Forecaster: GATZEN

SYNOPSIS

Intense polar trough remains over northern and central Europe. Another trough is forecast to move southward at the western flank of the European trough on THU. In the range of both troughs polar air mass will be likely be neutral to slightly unstable and diurnal heating may be sufficient for thunderstorms over Poland and northern Ukraine. Weak vertical wind shear will be present, and severe thunderstorms are not likely. To the south, axis of low geopotential is present from northern Mediterranean to southern Iberian Peninsula, where upper cut-off low will remain quasi-stationary. In the range of this cut-off low, neutral to unstable lapse rates are expected, and thunderstorms are forecast to go on. Weak vertical wind shear will not support organized convection.

DISCUSSION

Southern Adriatic

Trough axis of Mediterranean trough will propagate southward, and QG forcing is expected in the range of a strong jet stream at the southern flank of the trough. In the range of the trough, steep mid-level lapse rates as indicated by latest ascends are expected over southern Adriatic. Given some QG forcing as well as lift near the Balkan coast thunderstorms are forecast to form. Given strong deep layer vertical wind shear in the range of the upper jet, multicells and maybe mesocyclones are forecast, capable of producing severe wind gusts and isolated large hail.