A very complex forecast with low confidence with the location and intensity of the thunderstorm. We are expected to see two rounds of thunderstorm at night as a band of heavy rain react to mild southeasterly wind. Therefore a large slight risk and an area of marginally enhanced risk has been issued for parts of the south and west.
There is a strong sign of a convergence zone develop across the Celtic sea and move north/ northwest to parts of Northern and eastern parts of Ireland in the early morning, bring very heavy rain and gusty wind. Therefore an severe storm risk is issued for risk of gusty wind and torrential downpour. There is also a slight risk of few brief waterspout/ tornado possible somewhere across the severe storm area. Few sporadic thunderstorms are possible too.
Further band of heavy rain will push northward to the Celtic sea in the evening, sporadic thunderstorms are possible to develop as when they meet the southeasterly flow. Cape of 500-700 J/kg is possible across parts of Southwest England, Western parts of Wales, Northwest England and southeastern parts of Ireland. Therefore a high-ended slight risk is issued to these parts. However, the location of the band of rain remain uncertain which will influence the accuracy of the forecast.
Overnight, another convergence zone might develop across southern England when southwesterly meet the southeasterly flow, which will further develop into strong thunderstorm and heavy rain. The exact location will be very hard to pin-point as there is a very poor cross-model agreement. Therefore a very low-ended enhanced risk has been issued across the LOW and parts of Southeast England, elsewhere across West Midland, East Anglia and Northeast England might also see some strong thunderstorm but confident is too low to issue an enhanced risk.
Issued at: 19:25 (BST) 03/09/2022
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