ok found a TORRO paper from the international journal of meteorology Aug 2010 which says that the previous year tornado watches gave rise to one or more tornadoes in 19% of the watches and 41% occurred during a convective discussion, which is actually not a bad hit rate as they are very hard to forecast. There are lots of discussions as to when tornado watches should be issued - with the bias towards issuing tornado watches when significant tornadoes may occur and trying to envelope weak, short lived tornadoes into convective discussions, so that tornado watches are not overly issued and mean that people should perhaps pay attention when they are issued. There is still work to be done as always though in that year 46% were not forecast.
nice Gloria wfrances, even if we were guaranteed to have a widespread outbreak (which is rather unlikely!) your dh would be incredibly unlucky! I cant remember the percentage accuracy of TORROs forecasts. It is quite reasonable. I'll have to try and dig the paper out.
ESTOFEX (the european storm forecast experiment) have issued a level 1 storm forecast for the possibly of tornadoes and severe windgusts too. They run their level 1 area into the SE, having moved it slightly south of the TORRO forecast.
TORROhave issued a tornado watch and a convective discussion today for the interaction of a cold front with a large upper trough (creating an unstable and dynamic atmosphere) There may possibly be some tornadoes generated, also largish hail and cloud-ground lightning. Keep an eye on local weather conditions before heading off for out door activities. The cold front is showing up nicely on the met office radar