Convective Outlook: Thu 12 Jul 2018
What do these risk levels mean?
Convective Outlook

VALID 06:00 UTC Thu 12 Jul 2018 - 05:59 UTC Fri 13 Jul 2018

ISSUED 08:47 UTC Thu 12 Jul 2018


UPDATE 08:47 UTC No changes to the forecast for now - 00z observed and forecast soundings continue to suggest skinny CAPE which may be limited in height somewhat, and as such lightning may be rather sporadic / isolated - best potential over Wales where an upgrade to SLGT may still be possible. Given notable low-level convergence and favourable low-level wind fields, combined with low cloud bases, there could be several reports of funnel clouds today

Subtly falling heights and moistening with depth will provide the potential for some deep convection on Thursday. A few scattered heavy showers are likely in response to diurnal heating, low-level convergence and orographic forcing - and given very little steering flow, slow storm-motion could produce some locally high rainfall totals. With regards to lightning potential, instability is a little limited with very skinny CAPE. Rather saturated looking profiles and fairly weak shear casts some uncertainty as to whether much lightning will actually occur. As a result, have refrained from issuing a SLGT for now - though parts of Wales / SW England / W Country may require an upgrade if confidence improves. Main threats will be local surface water issues, especially considering existing very dry ground with dust/dirt deposits on roads likely to make surfaces rather slippery when wet.