Convective Outlook: Sat 24 Jun 2023
LOW
SLGT
MDT
HIGH
SVR
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Convective Outlook

VALID 06:00 UTC Sat 24 Jun 2023 - 05:59 UTC Sun 25 Jun 2023

ISSUED 06:30 UTC Sat 24 Jun 2023

ISSUED BY: Dan

An upper ridge over western Europe will build more strongly across Britain on Saturday, leading to capped profiles in many areas despite strong surface heating. Ireland/Northern Ireland will be on the western flank of the ridge, with stronger S/SW flow aloft, and while surface-based capping will be weaker forecast soundings reveal a notable warm nose in the 700-800hPa layer, largely suppressing any surface-based convection - however, if any thunderstorms can develop, the environment would be favourable for supercells capable of producing large hail. This mid-level nose is weaker with northwestward extent, such that there may be a small window of opportunity towards the evening for the likes of Mayo/Sligo/Donegal where some deep convection may just be possible, aided perhaps by an approaching shortwave embedded within the SW flow aloft. As such, a few heavy showers/thunderstorms could develop here late in the day, and will then be advected NNEwards towards the Outer Hebrides (chance here also for supercells), perhaps with renewed thunderstorm development close to (but probably to the west of) the Outer Hebrides overnight too.

In addition, a cold front approaching from the Atlantic will bring a band of showery rain eastwards into western and later central Ireland during the evening and night hours. There may be some embedded thunderstorms with this, although possibly with a weakening trend later in the night. Nonetheless, strong low-level shear along the frontal boundary with modest CAPE may pose the threat for an isolated tornado, this most pronounced close to coastal areas as convection tends to become more elevated further inland due to lower surface temperatures.