VALID 06:00 UTC Fri 28 Apr 2023 - 05:59 UTC Sat 29 Apr 2023

ISSUED 07:12 UTC Fri 28 Apr 2023

ISSUED BY: Dan

Beneath a mid/upper-level ridge, a residual moist low-level airmass will persist across Ireland/Northern Ireland on Friday with dewpoints typically 10-13C. Assuming extensive low cloud erodes through the day, increasing insolation and resultant surface heating may yield ~500 J/kg MLCAPE. This, in conjunction with increasing low-level wind convergence in the slack pressure pattern, may encourage deep convection and a scattering of heavy showers to develop. Modified forecast soundings suggest ELTs could reach -35C/cloud tops around 24,000ft. However, the upper troposphere is rather dry with subsidence aloft in the vicinity of the aforementioned ridge, while effective shear is also fairly weak, and this casts some uncertainty over how deep/sustained convection may be, and therefore the likelihood of any lightning. Nonetheless, heavy showers are plausible in various parts of Ireland, with the best potential for lightning probably across southern Ireland where more substantial low-level convergence may aid with forced ascent to sustain convection for longer. Tentatively introduced a low-end SLGT, but confidence in much in the way of lightning is low.