TORRO tornado watch just issued for S England...
http://www.torro.org.uk/site/forecast.phpTORRO TORNADO WATCH 2010/009 (PLEASE NOTE TCD017 is still in effect, see below).
A TORNADO WATCH has been issued at 09:15GMT on Thursday 11th November 2010
Valid from/until: 09:15 - 18:00GMT on Thursday 11th November 2010, for the following regions of the United Kingdom & Eire:
Parts of (see map)
Central and southern England
Much of Wales
THREATS
Tornadoes; wind gusts to 60-65mph; isolated CG lightning.
SYNOPSIS
Deep Atlantic low will cross Scotland today. Frontal system is moving across England and Wales, with a split cold front evident. Along the surface front, line convection is possible. Strong low-level shear suggests that misocyclone development is possible, with an associated tornado/strong-severe wind gust risk. In addition, a strong mid-level jet streak will nose into southern parts of England through this morning. Ascent associated with this looks like causing a small frontal wave to develop and move across parts of S England later this morning and through this afternoon. Rear-inflow into any cells/lines which develop along this may allow strong winds to develop. In addition, a few tornadoes are possible. Convection is expected to be rather shallow so lightning is not generally expected - however, a small risk exists with any vigorous convection, especially across southern parts of England.
Forecaster: RPK
TORRO CONVECTIVE DISCUSSION 2010/017
A TORRO CONVECTIVE DISCUSSION has been issued at 17:35GMT on Wednesday 10th November 2010
Valid from/until: 0000-2359GMT on Thursday 11th November 2010 for the following regions of the United Kingdom & Eire:
England
Wales
Scotland
N Ireland
Ireland
THREATS
Wind gusts to 65-75mph; tornadoes; occasional CG lightning; hail
SYNOPSIS
Rapidly deepening Atlantic storm will push an occluding frontal system across the British Isles overnight and through Wednesday. Instability along the occluded front and cold front is not predicted to be deep and very large; however, a forced line of shallow convection is possible across parts of Eire/N Ireland, and into Scotland/N England later tonight and for a time tomorrow morning. Strong ascent across northern parts of Ireland and N Ireland and into W Scotland could lead to somewhat deeper convection here, with a risk of thunder. Wind gusts of 50-65mph possible, along with isolated tornadoes.
Across Wales and central and southern parts of England, the cold front is forecast to split, with the surface cold front making somewhat slower eastwards progress than further north. Thus the risk of line convection is lower here. However, across S Wales and southern parts of England, as the upper trough extends SE'wards and a strong mid-level jet streak rounds the base of this, a wave may develop along the cold front in the SW approaches during the morning hours and then move eastwards across southern parts through the middle of the day and into the afternoon hours. Shallow convection may develop in a rather strongly-sheared environment. Broken convective lines are possible with rear-inflow, promoting severe wind gusts (55-65mph) along with a few tornadoes. A tornado watch may be required tomorrow morning for this.
Further north, behind the front heavy showers and few thunderstorms are expected, especially close to western coasts. Strong-severe wind gusts are likely with these.
Forecaster: RPK