Tornado watch has been issued by Torro now
http://www.torro.org.uk/site/forecast.php
TORRO TORNADO WATCH 2010/008
A TORNADO WATCH has been issued at 17:50GMT on Sunday 7th November 2010
Valid from/until: 17:50 - 13:00GMT on Sunday 7th/Monday 8th November 2010, for the following regions of the United Kingdom & Eire:
Parts of (see map)
Eire
N Ireland
Western and southern Wales
SW & Central Southern England
THREATS
Tornadoes; hail; thunderstorm wind gusts to 55 knots; torrential rain; and isolated cloud-ground lightning.
SYNOPSIS
Rather intense Atlantic storm will push an occluding frontal system into western parts of the British Isles overnight. The triple point is likely to cross Eire and thence into the S Wales/SW England area. To the north of this feature, the eastward progression of the frontal system is likely to become very slow, whereas the southern portion of the front continues eastwards across southern coastal counties of England through Monday morning.
Hi-resolution models simulate a forced line of convection along the cold front/occlusion. In addition, there is the suggestion of misocylones along the front, and given the strong vertical wind shear, and sharp veer across the front, seems reasonable. Stong convergence along the front and INVOF misocyclones should promote fairly strong updraughts in the lower atmosphere. The backed flow, and hence increased low-level shear INVOF misocyclones, and perhaps topographical features, suggests a tornado risk. In addition, strong wind gusts are likely, although these may non-convective in nature at times. Close to the triple-point depression, increased deep lift and the advection of reasonably warm air from the English Channel may enhance the thunder risk, and perhaps pose a risk of hail, locally heavy.
Behind the frontal system, showers and thunderstorms are expected across parts of S Eire, SW England and S Wales through Monday.
Forecaster: RPK