Sunday's outlook from Tony Gilbert...
Slight Risk of isolated Thunderstorms & Severe Gusts UK & Ireland 00Z Sun- 12Z Mon
Slight Risk of Tornado Development central south UK through to E. Anglia 10Z-17Z Sunday
A complex forecast with several areas at risk of thunderstorms with hail and severe gusts, though pretty much spread out over a large area. Regions at risk of isolated stronger convection are relatively sparse in nature and would be almost impossible to mark with separate convective boxes. Prime attention ATM is given to the risk of a tornado event red box during Sunday. Sharp surface trough expected to develop along the English Channel during Sun morning triggering some heavy rain and convective showers inland within a highly sheared environment. PV is stacked vertically and a breakaway upper trough influences lift in the region. ATM there looks to be some restriction regarding the dry intrusion which looks to remain offshore. This is the missing link and is the reason behind issuing a 'Slight' risk instead of a 'Moderate' risk for tornado genesis!....the potential here nevertheless should be regarded as high priority; Streamlining is actually shown to bow around part of this trough. This is not a common prediction for surface troughing as I can recall. Possible suggestive of some very localised low pressure building at surface! The potential for low level directional shear under these conditions could be exceptional!!
A further risk extended into Mon morning as a cold front and TP moves east bringing another round of thundery showers along the English Channel. Though based on a calculation of storm steering winds this potentially strong convection looks to remain just offshore! A small variation in wind vector could just as easily bring this lot ashore am Mon.
