VALID 06:00 UTC Thu 17 Oct 2019 - 05:59 UTC Fri 18 Oct 2019

ISSUED 07:03 UTC Thu 17 Oct 2019

ISSUED BY: Dan

Large upper vortex will slowly approach from the Atlantic on Thursday, spreading increasingly cold air aloft across the British Isles. This will result in increasingly steep mid-level lapse rates, with numerous showers and a few thunderstorms developing in response to relatively warm SSTs and increased forcing aloft. Showers will tend to become organised into bands at times, these migrating progressively eastwards across the British Isles - and so penetrating further inland as a result (particularly on Thursday night). Occasional, sporadic lightning will be possible, particularly close to exposed coastal areas where CAPE will be highest (500-900 J/kg). Hail is likely in many of the showers, generally small but potentially up to 1.5cm in diameter in the most intense cells, along with gusty winds.