Storm Forecast
Valid: Mon 31 Jan 2011 06:00 to Tue 01 Feb 2011 06:00 UTC
Issued: Sun 30 Jan 2011 22:26
Forecaster: DAHL

No threat levels issued.

... SYNOPSIS ...

A rather intense meandering upper frontal zone is stretching across the northern parts of Europe while a fairly large quasi-stationary upper cut-off low persists over the SW Mediterranean regions and Iberia. This pattern is reflected in the SFC analyses that show several intense SFC lows over the N Atlantic and N Europe, a belt of high pressure over the central portions of Europe, and weak low pressure over the central Mediterranean E of the cut-off cyclone.

... DISCUSSION ...

... western and central Mediterranean Sea ...

A few hundred Joules of CAPE are anticipated in the subtropical air mass E of the Mediterranean upper low. GFS advertises 25 m/s DLS in parts of this air mass, suggesting that some of the storms may become organized into linear segments and/or mesocyclones. It thus seems that an isolated severe wind event and maybe some hail cannot be ruled out, but weak instability and somewhat weak forcing for upward motion will limit the overall severe threat.

Some convection should also occur in the modified polar air over the western Mediterranean near the upper lows center. Shear will be marginal, but it seems that a few waterspouts could occur given strong low-level buoyancy.

... British Isles ...

An intense Atlantic system will reach the British Isles late in the period. It seems that there exists a small chance of strongly forced convection along the cold front, which is a scenario that has been associated with isolated tornadoes and severe wind gusts in the past. However, the signals in the models in favor of
such a line are very weak, so the probabilities of severe convective weather appear quite low.