Storm Forecast
Valid: Mon 14 Dec 2009 06:00 to Tue 15 Dec 2009 06:00 UTC
Issued: Sun 13 Dec 2009 21:01
Forecaster: DAHL

No threat levels have been issued

SYNOPSIS

A deep quasi-stationary long-wave upper trough is stretching from SW Europe into N Russia. This trough is slowly closing of into a cut-off cyclone over Iberia. Concomitant DCVA-forced ascent will affect SE Spain
and the SW Mediterranean Sea on Monday. Another vort max, pivoting about the base of the large-scale trough is simulated to cross the central Mediterranean on Monday, reaching the Aegean Sea late in the day. These two upper features will maintain a SFC low that covers the central and western Mediterranean Sea, which will bet the focus for convective development on Monday. Elsewhere, cold and stable conditions should preclude any severe/electrified convective activity.

DISCUSSION

... SE Spain ... SW Mediterranean ...

Minimal instability and 10 to 15 m/s deep shear will coinide with rather strong forcing for upward motion ahead of the Iberian cut-off low. In addition, strong LL warm advection/frontogenesis is in place over the SW Mediterranean, which should contribute to the upward forcing. Scattered convection should form as a result, but it seems that shear and instability will be too weak to support organized storms. In addition, the low-level forcing for upward motion will likely not be very focused, which also hints at a lack of storm organization. Much precipitation is simulated in this region, but it seems that it will be tied mainly to mesoscale frontogenetic ascent, rather than to the convective activity.

... Ionian Sea ... Aegean Sea ...

The scenario farther east is rather smilar to the one over the SW Mediterranean, but advectively-steepened lapse rates as well as stronger DCVA may support somewhat deeper convection. The shear profiles seem to be somewhat stronger, so that some of the cells may become weakly organozed, capable mainly of strong wind gusts. Strong WAA/frontogenesis will maintain widespread/intense ascent, supporting large amounts of precip. Though scattered convection will likely be imbedded in this vertical-motion regime, it is currently not thought to be causative of the precip threat.
Altogether, severe probabilities are too low
For a LVL1.