Convective Outlook: Thu 07 Apr 2022
LOW
SLGT
MDT
HIGH
SVR
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Thu 07 Apr 2022 - 05:59 UTC Fri 08 Apr 2022

ISSUED 06:39 UTC Thu 07 Apr 2022

ISSUED BY: Dan

An upper low will drift southeastwards across the North Sea to Denmark on Thursday, leaving a cool northwesterly flow on the rear side over the UK/Ireland. A strong westerly jet over southern Britain will gradually retreat southwards through the day, but with a ribbon of shear vorticity on its northern flank, which will generally straddle C Ireland - Wales - Midlands - E Anglia. An occlusion and associated showery rain will drift southwards across northern England and Northern Ireland, but likely becoming more fragmented/increasingly convective in nature with time. A zone of steeper mid-level lapse rates will connect the aforementioned upper low to the east with a substantial cold pool expanding southeastwards across Scotland and Northern Ireland. This W-E zone will be located over northern England during the morning, before gradually drifting southwards over the Midlands and East Anglia during the afternoon. As such, a narrow corridor of potential for deeper convection will exist from N England southwards into the Midlands/East Anglia, with the west-northwesterly steering flow generally favouring eastern portions of these regions. 

A few hundred J/kg CAPE (T/Td of 8-10C / 1-4C) in conjunction with one or two confluence zones could provide the focus for lines/clusters of heavy showers to develop and drift southeastwards. The depth of convection and thermodynamic profile would be supportive of some sporadic lightning, but given fairly strong flow at all levels the cloud-layer shear will probably be around 15-20kts at best - still sufficient to aid some cell organisation/longevity. Small hail and gusty winds (50-60mph) may accompany the strongest cells. A low-end SLGT has been introduced where the greatest risk of some lightning is considered, but realistically a few odd strikes could occur just about anywhere. Another area of interest may be W / C Ireland, but here profiles are rather dry with weaker shear. Any showers that develop over southern Britain will likely be shallower in depth but in a stronger shear environment, so this may be sufficient to compensate for the limited CAPE to produce a few odd lightning strikes. Frequent showers will also pile into northern and western Scotland and northern coasts of Ireland/Northern Ireland, continuing overnight, with a few isolated strikes possible in places.